DW3
Comstock/Stockbyte/Thinkstock Learning Objectives After studying this chapter, you should be able to: • Describe how solar and wind power systems work and how—along with other forms of renewable energy—these technologies can help us move away from a dependence on fossil fuel energy sources. • Explain how hydropower and geothermal energy systems work, and review their advantages and disad- vantages relative to other forms of energy. • Discuss the major drawbacks of nuclear power and why this technology may not be the best approach to reducing the carbon footprint of our energy system. • Explain what energy efficiency means and how efficiency can help us meet our energy needs while simultaneously reducing energy consumption and the environmental impacts of energy use. • Describe the features and components of a net-zero energy office building and how a combination of technology and behavioral changes help these buildings use only as much energy as they produce. Renewable Energy, Nuclear Power, and Energy Efficiency 8 ben85927_08_c08.indd 325 1/30/14 8:36 AM Intro Duct Ion Pre-Test 1. Which of the following is not one of the policy options recommended to help speed up the adoption of renewable energy technologies? a. Implementation of a feed-in tariff b. t axing fossil fuels to reflect their externality costs c. Subsidizing corn ethanol production d. Investing in an improved long-distance power transmission system 2. It could be said that hydroelectric power is always renewable and always sustainable. a. t rue b. False 3. Which of the following is not a radioactive byproduct of nuclear power production? a. c esium-137 b. Plutonium c. Strontium-90 d. Bauxite 4. Energy efficiency focuses more on the supply side than the demand side. a. t rue b. False 5. A “net-zero energy” building is designed to use no energy at all. a. t rue b. False Answers 1. c. Subsidizing corn ethanol production. the answer can be found in section 8.1. 2. b. False. the answer can be found in section 8.2. 3. d. Bauxite. the answer can be found in section 8.3. 4. b. False. the answer can be found in section 8.4. 5. b. False. the answer can be found in section 8.5. Introduction Walk around your home and take note of all of the devices that you leave plugged in whether or not they are in use. televisions, computers, refrigerators, alarm clocks, and cell phone chargers all constantly use energy. next, try to imagine the sum of such energy consumption that occurs in the more than 100 million households across the entire united States. Add to that all of the electricity, home and commercial heating and cooling, manufacturing, and fuel used to power various methods of transportation. now, still in your imagination, expand this sum of consumption to include all the other countries throughout the world.
the staggering sum of energy consumption across the world has been quantified by the Energy Information Agency (EIA) of the united States. the EIA estimates that world energy consumption was approximately 500 quadrillion Btu (British thermal units) in 2010 ( u.S. Energy Information Administration, 2010). It’s difficult to attach a human scale to this num- ber. Five hundred quadrillion Btu is the energy equivalent of 10 million atomic bombs of the size dropped on Hiroshima in 1945. And by 2035, the EIA predicts that global energy con - sumption will increase to 770 quadrillion Btu. ben85927_08_c08.indd 326 1/30/14 8:36 AM Intro Duct Ion When we look into the future, we face the certainty that fossil fuel reserves will become depleted. Indeed, in 2010 about 90 percent of global energy supply was furnished by fossil fuels (BP, 2010). Experts agree that alternative energy sources must be developed in order to keep up with global energy demands and avoid catastrophic climate changes. not surpris - ingly, though, experts also disagree over whether there is sufficient will and investment to convert to an alternative energy economy without a significant change in our lifestyles. In this chapter we will examine the risks of using nuclear energy sources, as well as explore the plausibility of using various renewable energy sources as we seek the answer to the following question: can global society make the massive shift to using wind turbines, solar power, and other renewable energy sources to replace the current reliance on fossil fuels?
the two most important sources of renewable energy reviewed in this chapter are solar and wind power. We’ll see that solar comes in a variety of forms, including solar photovoltaic (PV) panels that can be placed on rooftops to generate electricity and large-scale concentrat - ing solar power ( cSP) systems that use mirrors to concentrate the sun’s rays and generate electricity. the power of the wind can be harnessed by wind turbines that, when grouped together in one area, are referred to as a wind farm . other renewable energy sources touched on to varying degrees in this chapter include a variety of water-based sources including hydropower, wave power, and tidal power; geothermal energy or energy from the ground; and a variety of forms of biomass energy derived from plants and other living organisms. In addition, the chapter will have a lot to say about energy efficiency—an approach to using less energy while accomplishing the same tasks and amount of work.
A key difference between non-renewable and renewable energy sources can be illustrated through the concepts of stocks and flows. non-renewable energy sources such as oil and coal currently exist in fixed amounts or stocks. We cannot hope for any significant increase in these stocks. the high-energy content and versatility in use of these fossil fuel stocks makes them especially attractive as a form of energy. In contrast, renewable energy sources such as wind and sunlight are available not as fixed stocks of energy but as flows. these flows are renewable in that the sun will keep shining and the wind will keep blowing no matter how much we make use of them. In addition, these flows are massive—the total energy contained in one hour of sunlight shining on the Earth is more than all of the commercial energy con - sumed on the planet in one year, and the energy contained in wind represents more than 15 times the global energy demand.
However, unlike highly energy-dense fossil fuels, these renewable energy flows are diffuse and intermittent. We have to deploy and develop extensive areas of solar panels and wind turbines to capture enough energy to meet demand, and we have to account for the fact that in a given location, on a particular day, the sun may not shine or the wind may not be strong enough to generate power. In this way we can categorize non-renewable fossil fuel energy sources as stock-limited and renewable energy sources as flow-limited.
In order to more effectively make use of renewable energy technologies, we must pair their adoption with improvements in the efficiency of energy use. By first reducing energy demand through better lighting, appliances, windows, and insulation, we can reduce the quantity and magnitude of the renewable energy devices that need to be put in place to meet remain - ing energy demand. this concept of synergy between renewable energy and energy effi - ciency is best illustrated in so-called net-zero energy homes or buildings (see section 8.5). ben85927_08_c08.indd 327 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy Such structures produce as much energy as they consume over the course of a day, week, or month, and represent the feasibility of utilizing renewable energy sources to meet much of our energy needs. We also need to pay attention to issues of energy storage and how energy is distributed through the electric power grid. For renewable energy sources to really increase in prominence and importance, we’ll need to improve our electric grid so that power gener- ated from renewable sources can be distributed when and where it is needed.
one additional note on the terminology used in many of the readings in this chapter: A watt is a unit of energy, and the readings will refer to things like a megawatt (one million watts) and a terawatt (one trillion watts). For our purposes it might be easier to put these units into per- spective. For example, when the authors in section 8.1 refer to wind turbines that are rated at five megawatts capacity, they are describing a piece of equipment that, when operating at full capacity, can produce five megawatts of electric power. this is enough electricity to meet the needs of roughly 1,700 American households. the main issue that we’ll see with renewable energy is developing enough variety in sources so that energy needs are met in a specific loca - tion even if the wind is not blowing (or sun is not shining) at that moment.
8.1 Powering the World With Renewable Energy Chapter 7 made clear that if we are to avoid the worst consequences of global climate change, we will soon need to shift away from a reliance on fossil fuels and move toward renewable energy sources. However, fossil fuel industries and their supporters often claim that renewable energy is expensive, unreliable, and unable to meet the bulk of our energy needs for the foreseeable future.
In this article environmental scientists Mark Jacobson and Mark Delucchi challenge that claim and describe their plan for how the world can shift to renewable energy for 100 percent of its power needs by 2030. Specifically, Jacobson and Delucchi focus on a combination of wind, water, and sunlight (WWS) renewable energy systems to achieve this goal. Renewable energy sources offer numerous benefits, including that they can be produced domestically, they never “run out,” and they are virtually pollution free.
One major benefit of renewable solar energy is that it can be utilized in a number of different ways. Passive solar energy uses sunlight directly without any mechanical devices, such as when sunlight is used to illuminate or heat interior spaces. Active solar energy captures sunlight using mechanical devices and then converts it to useful heat or electric power. Solar photovoltaic or PV panels convert sunlight to electricity, which is the most common form of active solar energy.
You can find PV panels on solar calculators, rooftops, and streetlights and traffic signs. Another way to generate electricity using solar energy is through solar thermal or concentrating solar power (CSP) systems. These systems use mirrors to concentrate the sun’s rays on a tank or pipe filled with fluid. The heated fluid can then be used to produce steam used to spin a turbine to generate electricity.
Wind turbines are mechanical devices that convert the kinetic energy of the wind into electric power. Wind power development has been accelerating in recent years in such countries as Ger - many, Spain, the United States, and China. In terms of percentage share of total energy, Denmark is the world leader with more than 20 percent of their electricity needs produced from wind power. Denmark uses wind turbines located both on land and in offshore regions near the coast.
Such offshore areas have stronger and more consistent winds but are also more expensive to develop . ben85927_08_c08.indd 328 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy Jacobson and Delucchi’s plan calls for over 90 percent of our energy needs to be met through solar and wind power sources. The remainder can be met by a mix of water-based and geo- thermal sources. Traditional hydroelectric power and geothermal energy are described in more detail in the next section, but it’s worth mentioning here what is meant by wave and tidal power.
Wave power is essentially another form of wind power since it is designed to harness the energy of waves, which are driven by the winds. Tidal power takes advantage of differences in tides and the power of water moving with those tidal changes to also generate electricity. You can learn more about how wave and tidal power work by examining these sources (http://www.ucsusa .org/clean_energy/our-energy-choices/renewable-energy/how-hydrokinetic-energy -works.html and http://science.howstuffworks.com/environmental/earth/oceanography /wave-energy1.htm) and others listed in the Additional resources section at the end of the chapter.
Finally, it’s important to point out the role that economics and politics play in a transition to renewable energy. Jacobson and Delucchi make clear that when you factor in the externality costs—the monetary value of health and environmental damage—of using fossil fuels, these sources of energy are often more expensive than they first appear. Combine that with the rapid rate of decline in the costs of renewable energy sources such as solar and wind and it becomes apparent that there are sound economic arguments in favor of a renewable energy system. While the economics are increasingly favorable for renewable energy, it is the lack of political will to implement these sources and strong lobbying of politicians by the fossil fuel industry that most impede their development. Ironically, fossil fuels are already among the most heavily subsidized industries in the world, especially in the United States. This reading calls for an elimination of those subsidies and the implementation of incentives to promote the development of renewable energy alternatives. Such a policy approach makes both economic and environmental sense but will require a change in our current political approach to energy issues. By Mark Z. Jacobson and Mark A. Delucchi In December [2009] leaders from around the world will meet in copenhagen to try to agree on cutting back greenhouse gas emissions for decades to come. the most effective step to implement that goal would be a massive shift away from fossil fuels to clean, renewable energy sources. If leaders can have confidence that such a transformation is possible, they might commit to an historic agreement. We think they can. A year ago former vice president Al gore threw down a gauntlet: to repower America with 100 percent carbon-free electricity within 10 years. As the two of us started to evaluate the feasibility of such a change, we took on an even larger challenge: to determine how 100 percent of the world’s energy, for all pur- poses, could be supplied by wind, water and solar resources, by as early as 2030. our plan is presented here.
Scientists have been building to this moment for at least a decade, analyzing various pieces of the challenge. Most recently, a 2009 Stanford university study ranked energy systems according to their impacts on global warming, pollution, water supply, land use, wildlife and other concerns. the very best options were wind, solar, geothermal, tidal and hydroelectric ben85927_08_c08.indd 329 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy power—all of which are driven by wind, water or sunlight (referred to as WWS).
nuclear power, coal with carbon capture, and ethanol were all poorer options, as were oil and natural gas. the study also found that battery-electric vehicles and hydrogen fuel-cell vehicles recharged by WWS options would largely eliminate pollution from the transportation sector.
our plan calls for millions of wind tur - bines, water machines and solar instal - lations. the numbers are large, but the scale is not an insurmountable hurdle; society has achieved massive transfor- mations before. During World War II, the u.S. retooled automobile factories to produce 300,000 aircraft, and other countries produced 486,000 more. In 1956 the u.S. began building the Inter - state Highway System, which after 35 years extended for 47,000 miles, changing commerce and society.
Is it feasible to transform the world’s energy systems? could it be accom - plished in two decades? the answers depend on the technologies chosen, the availability of critical materials, and economic and political factors.
Clean Technologies Only renewable energy comes from enticing sources: wind, which also produces waves; water, which includes hydroelectric, tidal and geothermal energy (water heated by hot underground rock); and sun, which includes photovoltaics and solar power plants that focus sunlight to heat a fluid that drives a turbine to generate electricity. our plan includes only technologies that work or are close to working today on a large scale, rather than those that may exist 20 or 30 years from now.
to ensure that our system remains clean, we consider only technologies that have near-zero emissions of greenhouse gases and air pollutants over their entire life cycle, including con- struction, operation and decommissioning. For example, when burned in vehicles, even the most ecologically acceptable sources of ethanol create air pollution that will cause the same mortality level as when gasoline is burned. nuclear power results in up to 25 times more car - bon emissions than wind energy, when reactor construction and uranium refining and trans - port are considered. carbon capture and sequestration technology can reduce carbon dioxide emissions from coal-fired power plants but will increase air pollutants and will extend all the other deleterious effects of coal mining, transport and processing, because more coal must be Consider This the main factor that determines whether a battery-electric car is “greener” than a gasoline-powered vehicle is how electric - ity is produced in a specific area. If a signif- icant portion of the electricity comes from renewable and clean sources like solar and wind, then a battery-electric car can be very green. However, in areas where elec- tricity comes mainly from coal, a gasoline- powered car might actually be “greener” than a battery-electric vehicle.
First read this article: http://www.ny times .com/2012/04/15/automobiles /how-green-are-electric-cars-depends -on-where-you-plug-in.html next, explore the resources at this union of concerned Scientists site and determine how green a switch to a battery-electric vehicle would be in your area: http:// www.ucsusa.org/clean_vehicles/smart -transportation-solutions/advanced - vehicle -technologies/electric-cars /emissions-and-charging-costs-electric -cars.html ben85927_08_c08.indd 330 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy burned to power the capture and storage steps. Similarly, we consider only technologies that do not present significant waste disposal or terrorism risks.
In our plan, WWS will supply electric power for heating and transportation—industries that will have to revamp if the world has any hope of slowing climate change. We have assumed that most fossil-fuel heating (as well as ovens and stoves) can be replaced by electric sys- tems and that most fossil-fuel transportation can be replaced by battery and fuel-cell vehicles.
Hydrogen, produced by using WWS electricity to split water (electrolysis), would power fuel cells and be burned in airplanes and by industry.
Plenty of Supply today the maximum power consumed worldwide at any given moment is about 12.5 tril - lion watts (terawatts, or tW), according to the u.S. Energy Information Administration. the agency projects that in 2030 the world will require 16.9 tW of power as global popula - tion and living standards rise, with about 2.8 tW in the u.S. the mix of sources is similar to today’s, heavily dependent on fossil fuels. If, however, the planet were powered entirely by WWS, with no fossil-fuel or biomass combustion, an intriguing savings would occur. global power demand would be only 11.5 tW, and u.S. demand would be 1.8 tW. that decline occurs because, in most cases, electrification is a more efficient way to use energy. For example, only 17 to 20 percent of the energy in gasoline is used to move a vehicle (the rest is wasted as heat), whereas 75 to 86 percent of the electricity delivered to an electric vehicle goes into motion.
Even if demand did rise to 16.9 tW, WWS sources could provide far more power. Detailed studies by us and others indicate that energy from the wind, worldwide, is about 1,700 tW. Solar, alone, offers 6,500 tW. of course, wind and sun out in the open seas, over high moun - tains and across protected regions would not be available. If we subtract these and low-wind areas not likely to be developed, we are still left with 40 to 85 tW for wind and 580 tW for solar, each far beyond future human demand. yet currently we generate only 0.02 tW of wind power and 0.008 tW of solar. these sources hold an incredible amount of untapped potential. the other WWS technologies will help create a flexible range of options. Although all the sources can expand greatly, for practical reasons, wave power can be extracted only near coastal areas. Many geothermal sources are too deep to be tapped economically. And even though hydroelectric power now exceeds all other WWS sources, most of the suitable large reservoirs are already in use.
The Plan: Power Plants Required clearly, enough renewable energy exists. How, then, would we transition to a new infrastruc - ture to provide the world with 11.5 tW? We have chosen a mix of technologies emphasiz - ing wind and solar, with about 9 percent of demand met by mature water-related methods. (other combinations of wind and solar could be as successful.) Wind supplies 51 percent of the demand, provided by 3.8 million large wind turbines (each rated at five megawatts) worldwide. Although that quantity may sound enormous, it is inter - esting to note that the world manufactures 73 million cars and light trucks every year. Another 40 percent of the power comes from photovoltaics and concentrated solar plants, with about ben85927_08_c08.indd 331 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy 30 percent of the photovoltaic output from rooftop panels on homes and com- mercial buildings. About 89,000 photo - voltaic and concentrated solar power plants, averaging 300 megawatts apiece, would be needed. our mix also includes 900 hydroelectric stations worldwide, 70 percent of which are already in place.
only about 0.8 percent of the wind base is installed today. the worldwide foot - print of the 3.8 million turbines would be less than 50 square kilometers (smaller than Manhattan). When the needed spac - ing between them is figured, they would occupy about 1 percent of the earth’s land, but the empty space among turbines could be used for agriculture or ranching or as open land or ocean. the nonrooftop photovoltaics and concentrated solar plants would occupy about 0.33 percent of the planet’s land. Building such an extensive infrastructure will take time. But so did the current power plant network. And remember that if we stick with fossil fuels, demand by 2030 will rise to 16.9 tW, requiring about 13,000 large new coal plants, which themselves would occupy a lot more land, as would the mining to supply them.
Smart Mix for Reliability A new infrastructure must provide energy on demand at least as reliably as the existing infrastructure. WWS technologies generally suffer less downtime than traditional sources.
the average u.S. coal plant is offline 12.5 percent of the year for scheduled and unscheduled maintenance. Modern wind turbines have a down time of less than 2 per- cent on land and less than 5 percent at sea. Photovoltaic systems are also at less than 2 percent. Moreover, when an individual wind, solar or wave device is down, only a small fraction of produc- tion is affected; when a coal, nuclear or natural gas plant goes offline, a large chunk of generation is lost.
the main WWS challenge is that the wind does not always blow and the sun does not always shine in a given location. Intermittency problems can be mitigated by a smart balance of sources, such as generating a base supply from steady geothermal or tidal power, relying on wind at night when it . Felix-Andrei Constantinescu/iStock/Thinkstock Energy demands can be more effectively met by diversifying the use of renewable energy sources, like wind and solar. Consider This these short Energy 101 videos from the u.S. Department of Energy provide easy- to-understand explanations of how renew - able energy technologies actually work:
• Wind: http://energy.gov/videos /energy-101-wind-turbines • Solar photovoltaics: http://energy .gov/videos/energy-101-solar-pv • concentrating solar power: http:// energy.gov/videos/energy-101 -concentrating-solar-power ben85927_08_c08.indd 332 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy is often plentiful, using solar by day and turning to a reliable source such as hydroelectric that can be turned on and off quickly to smooth out supply or meet peak demand. For example, interconnecting wind farms that are only 100 to 200 miles apart can compensate for hours of zero power at any one farm should the wind not be blowing there. Also helpful is intercon- necting geographically dispersed sources so they can back up one another, installing smart electric meters in homes that automatically recharge electric vehicles when demand is low and building facilities that store power for later use.
Because the wind often blows during stormy conditions when the sun does not shine and the sun often shines on calm days with little wind, combining wind and solar can go a long way toward meeting demand, especially when geothermal provides a steady base and hydroelec - tric can be called on to fill in the gaps. Apply Your Knowledge one of the most common criticisms of wind power is that wind turbines are a major cause of bird and bat deaths. the u.S. Fish and Wildlife Service estimates that collisions with wind turbine blades kill close to 500,000 birds annually. However, this is a relatively small number compared to estimated bird deaths from other sources such as domestic cats and collisions with buildings, cell phone towers, and transmission lines. combined, these sources could be responsible for over one billion bird deaths annually. nevertheless, the wind power industry is exploring ways to better locate and construct wind turbines in order to minimize bird and bat mortality. Start by reviewing these readings on the subject:
• A detailed fact sheet on wind turbine interactions with birds and bats: http://national wind.org/wp-content/uploads/assets/publications/Birds_and_Bats_Fact_Shee\ t_.pdf • An article on how researchers are seeking ways to reduce wind turbine-related bird and bat mortality: http://www.nature.com/news/the-trouble-with-turbines-an-ill -wind-1.10849 • A handful of short articles and graphics showing common causes of bird mortality:
http://www.nytimes.com/2011/03/21/science/21birds.html , http://www.nssf.org /share/PDF/BirdMortality.pdf , and http://www.fws.gov/birds/mortality-fact-sheet.pdf After you review this information, consider the following scenario. Suppose a new wind farm consisting of 80–100 new wind turbines is being proposed for development in a rural area near you, and that you’ve been asked to complete a wildlife impact assessment for this proj- ect. Where would you start? What might you do to try to determine whether this wind farm would pose a serious threat to birds and bats in the area? Suppose the wind power developer informed you that they had a new device that they planned to attach to wind turbines to deter birds before they can collide with the structure. How might you design a scientific experiment to test the effectiveness of such a device? ben85927_08_c08.indd 333 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy As Cheap as Coal the mix of WWS sources in our plan can reliably supply the residential, commercial, indus - trial and transportation sectors. the logical next question is whether the power would be affordable. For each technology, we calculated how much it would cost a producer to gener- ate power and transmit it across the grid. We included the annualized cost of capital, land, operations, maintenance, energy storage to help offset intermittent supply, and transmission.
today the cost of wind, geothermal and hydroelectric are all less than seven cents a kilowatt- hour (¢/kWh); wave and solar are higher. But by 2020 and beyond wind, wave and hydro are expected to be 4¢/kWh or less.
For comparison, the average cost in the u.S. in 2007 of conventional power generation and transmission was about 7¢/kWh, and it is projected to be 8¢/kWh in 2020. Power from wind turbines, for example, already costs about the same or less than it does from a new coal or natural gas plant, and in the future wind power is expected to be the least costly of all options.
the competitive cost of wind has made it the second-largest source of new electric power generation in the u.S. for the past three years, behind natural gas and ahead of coal. Solar power is relatively expensive now but should be competitive as early as 2020. A careful analysis by Vasilis Fthenakis of Brookhaven national laboratory indicates that within 10 years, photovoltaic system costs could drop to about 10¢/kWh, including long-distance transmission and the cost of compressed-air storage of power for use at night. the same analysis estimates that concentrated solar power systems with enough thermal storage to generate electricity 24 hours a day in spring, summer and fall could deliver electricity at 10¢/kWh or less.
transportation in a WWS world will be driven by batteries or fuel cells, so we should com - pare the economics of these electric vehicles with that of internal-combustion-engine vehi - cles. Detailed analyses by one of us (Delucchi) and tim lipman of the university of califor - nia, Berkeley, have indicated that mass-produced electric vehicles with advanced lithium-ion or nickel metal-hydride batteries could have a full lifetime cost per mile (including battery replacements) that is comparable with that of a gasoline vehicle, when gasoline sells for more than $2 a gallon.
When the so-called externality costs (the monetary value of damages to human health, the environment and climate) of fossil-fuel generation are taken into account, WWS technologies become even more cost-competitive. overall construction cost for a WWS system might be on the order of $100 trillion worldwide, over 20 years, not including transmission. But this is not money handed out by governments or consumers. It is investment that is paid back through the sale of electricity and energy.
And again, relying on traditional sources would raise output from 12.5 to 16.9 tW, requiring thousands more of those plants, costing roughly $10 trillion, not to mention tens of trillions of dollars more in health, environmental and security costs. the WWS plan gives the world a new, clean, efficient energy system rather than an old, dirty, inefficient one.
Political Will our analyses strongly suggest that the costs of WWS will become competitive with traditional sources. In the interim, however, certain forms of WWS power will be significantly more costly than fossil power. Some combination of WWS subsidies and carbon taxes would thus be ben85927_08_c08.indd 334 1/30/14 8:36 AM SEct Ion 8.1 Po WE rIng t HE Worl D W ItH rE nEWAB lE En Ergy needed for a time. A feed-in tariff (FI t) program to cover the difference between generation cost and wholesale electricity prices is especially effective at scaling-up new technologies.
combining FI ts with a so-called declining clock auction, in which the right to sell power to the grid goes to the lowest bidders, provides continuing incentive for WWS developers to lower costs. As that happens, FI ts can be phased out. FI ts have been implemented in a number of European countries and a few u.S. states and have been quite successful in stimulating solar power in germany. taxing fossil fuels or their use to reflect their environmental damages also makes sense. But at a minimum, existing subsidies for fossil energy, such as tax benefits for exploration and extraction, should be eliminated to level the playing field. Misguided promotion of alterna- tives that are less desirable than WWS power, such as farm and production subsidies for biofu- els, should also be ended, because it delays deployment of cleaner systems. For their part, leg - islators crafting policy must find ways to resist lobbying by the entrenched energy industries.
Finally, each nation needs to be willing to invest in a robust, long-distance transmission sys- tem that can carry large quantities of WWS power from remote regions where it is often greatest—such as the great Plains for wind and the desert Southwest for solar in the u.S.—to centers of consumption, typically cities. reducing consumer demand during peak usage peri - ods also requires a smart grid that gives generators and consumers much more control over electricity usage hour by hour.
A large-scale wind, water and solar energy system can reliably supply the world’s needs, sig - nificantly benefiting climate, air quality, water quality, ecology and energy security. As we have shown, the obstacles are primarily political, not technical. A combination of feed-in tariffs plus incentives for provid - ers to reduce costs, elimination of fossil subsidies and an intelligently expanded grid could be enough to ensure rapid deployment. of course, changes in the real-world power and transportation industries will have to overcome sunk investments in existing infrastructure.
But with sensible policies, nations could set a goal of generating 25 percent of their new energy supply with WWS sources in 10 to 15 years and almost 100 percent of new supply in 20 to 30 years. With extremely aggressive policies, all existing fossil-fuel capacity could theoretically be retired and replaced in the same period, but with more modest and likely poli- cies full replacement may take 40 to 50 years. Either way, clear leadership is needed, or else nations will keep trying technologies promoted by industries rather than vetted by scientists.
A decade ago it was not clear that a global WWS system would be technically or economically feasible. Having shown that it is, we hope global leaders can figure out how to make WWS power politically feasible as well. they can start by committing to meaningful climate and renewable energy goals now. Consider This A far more detailed description of the 100 percent renewable energy plan described in this reading can be found in this two-part article by the same authors:
• http://www.stanford.edu/group /efmh/jacobson/Articles/I/JDEn PolicyPt1.pdf • http://www.stanford.edu/group /efmh/jacobson/Articles/I/DJEn PolicyPt2.pdf ben85927_08_c08.indd 335 1/30/14 8:36 AM SEct Ion 8.2 Tradi Tional renewables—Hydropower and Geo TH ermal Source: Jacobson, M. Z., & Delucchi, M. A. (2009 October). A Plan to Power 100 Percent of the Planet with Renewables. Scientific American. Retrieved from http://www.scientificamerican.com/article.cfm?id=a-path -to-sustainable-energy-by-2030 Reproduced with permission. Copyright © 2009 Scientific American, Inc. All rights reserved.
8.2 Traditional Renewables—Hydropower and Geothermal Decades before modern solar panels and wind turbines were developed, we used the energy con- tained in running water and under the Earth’s surface. Water-generated energy called hydro - electric power or hydropower taps the kinetic energy of moving water to generate electricity.
For over a century dams have been built in the United States to exploit this energy resource. Geo - thermal power makes use of heated water that is deep underground to produce steam to gener - ate electricity. Because the water cycle keeps water moving, and because the geologic conditions that produce underground hot water and steam will continue to do so indefinitely, hydropower and geothermal power are considered renewable forms of energy.
In the first part of the following section staff writers with the United States Geological Survey (USGS) review advantages and disadvantages associated with the development and use of hydro - power resources. The main advantage is that hydropower generates electricity without fossil fuel combustion, so there are no direct emissions of pollutants or greenhouse gases. However, because hydropower usually involves the construction of a dam in order to create a reservoir to hold water in place, it can have a number of ecological and social impacts. These include the destruction of wildlife habitat and homes as well as modification of river flow patterns. In this sense it might be fair to say that hydroelectric power is renewable but not always sustainable.
In the second part of this section staff writers with the National Renewable Energy Laboratory (NREL) explain some of the basics of geothermal power. Geothermal resources can directly pro - vide hot water for industrial purposes or be converted to electricity through geothermal power plants. The article points out that even the low-grade geothermal energy that exists under - ground nearly everywhere can be tapped to heat and cool homes and buildings. Such geother - mal heat pump systems make use of the relatively constant temperature of 50 to 608F just ten feet below the Earth’s surface to cool spaces in the summer and heat them in the winter. Both hydroelectric and geothermal power fit into the 100 percent renewable energy plan described in section 8.1, along with wave and tidal power systems. However, these energy sources are far more location-specific (e.g., near water or geothermal resources) than wind or solar, so they are expected to play a less important role in meeting future energy needs.
By the United States Geological Survey Hydropower Although most energy in the united States is produced by fossil-fuel and nuclear power plants, hydroelectricity is still important to the nation, as about 7 percent of total power is produced by hydroelectric plants. nowadays, huge power generators are placed inside dams. Water flowing through the dams spin turbine blades which are connected to generators. Power is produced and is sent to homes and businesses. ben85927_08_c08.indd 336 1/30/14 8:36 AM SEct Ion 8.2 Tradi Tional renewables—Hydropower and Geo TH ermal World Distribution of Hydropower • Hydropower is the most important and widely-used renewable source of energy. • Hydropower represents 19% of total electricity production. • china is the largest producer of hydroelectricity, followed by canada, Brazil, and the united States (Source: Energy Information Administration). • Approximately two-thirds of the economically feasible potential remains to be devel- oped. untapped hydro resources are still abundant in latin America, central Africa, India and china. Producing electricity using hydroelectric power has some advantages over other power- producing methods . let’s do a quick comparison: Advantages to hydroelectric power: • Fuel is not burned so there is minimal pollution • Water to run the power plant is provided free by nature • Hydropower plays a major role in reducing greenhouse gas emissions • relatively low operations and maintenance costs • the technology is reliable and proven over time • It’s renewable—rainfall renews the water in the reservoir, so the fuel is almost always there.
Disadvantages to power plants that use coal, oil, and gas fuel: • they use up valuable and limited natural resources • they can produce a lot of pollution • companies have to dig up the Earth or drill wells to get the coal, oil, and gas • For nuclear power plants there are waste-disposal problems Hydroelectric power is not perfect, though, and does have some disadvantages: • High investment costs • Hydrology dependent (precipitation) • In some cases, inundation of land and wildlife habitat • In some cases, loss or modifi - cation of fish habitat • Fish entrainment or passage restriction • In some cases, changes in reservoir and stream water quality • In some cases, displacement of local populations . Getty Images/Jupiterimages/Stockbyte/Thinkstock While Glen Canyon Dam provides electricity to major cities of the American West, it has also impacted the Colorado River ecosystem. Before the dam’s construction, the section of river below Glen Canyon contained silty, warmer water, favoring native fish such as humpback chub and razorback sucker. Since the dam’s completion, water below the dam tends to be colder and to favor trout. ben85927_08_c08.indd 337 1/30/14 8:36 AM SEct Ion 8.2 Tradi Tional renewables—Hydropower and Geo TH ermal Hydropower and the Environment Hydropower is nonpolluting, but does have environmental impacts Hydropower does not pollute the water or the air. However, hydropower facilities can have large environmental impacts by changing the environment and affecting land use, homes, and natural habitats in the dam area.
Most hydroelectric power plants have a dam and a reservoir. these structures may obstruct fish migration and affect their populations. operating a hydroelectric power plant may also change the water tem- perature and the river’s flow. these changes may harm native plants and animals in the river and on land. res - ervoirs may cover people’s homes, important natural areas, agricultural land, and archeological sites. So build - ing dams can require relocating people.
Methane, a strong greenhouse gas, may also form in some reservoirs and be emitted to the atmosphere.
Reservoir construction is “drying up” in the United States [H]ydroelectric power sounds great—so why don’t we use it to produce all of our power?
Mainly because you need lots of water and a lot of land where you can build a dam and res - ervoir, which all takes a lot of money, time, and construction. In fact, most of the good spots to locate hydro plants have already been taken. In the early part of the century hydroelectric plants supplied a bit less than one-half of the nation’s power, but the number is down to about 10 percent today. the trend for the future will probably be to build small-scale hydro plants that can generate electricity for a single community.
[t]he construction of surface reservoirs has slowed considerably in recent years. In the mid - dle of the 20th century, when urbanization was occurring at a rapid rate, many reservoirs were constructed to serve peoples’ rising demand for water and power. Since about 1980, the rate of reservoir construction has slowed considerably.
Typical Hydroelectric Powerplant [sic] Hydroelectric energy is produced by the force of falling water. the capacity to produce this energy is dependent on both the available flow and the height from which it falls. Building up behind a high dam, water accumulates potential energy. this is transformed into mechanical energy when the water rushes down the sluice and strikes the rotary blades of turbine. the turbine’s rotation spins electromagnets which generate current in stationary coils of wire.
Finally, the current is put through a transformer where the voltage is increased for long dis- tance transmission over power lines. Consider This What are the most significant advantages and disadvantages associated with the development and use of hydropower?
Based on a review of these, is this an energy source we should be trying to increase use of ? ben85927_08_c08.indd 338 1/30/14 8:36 AM SEct Ion 8.2 Tradi Tional renewables—Hydropower and Geo TH ermal Figure 8.1: Hydroelectric power generation Hydroelectric dams generate electricity via the force of falling water. once a river is blocked by a dam to form a reservoir, the dam’s sluice gates can be opened, allowing falling water to push powerful turbines that generate electricity. the electric current is run through a transformer to prepare it for transmission to utility customers.
Hydroelectric-power production in the United States and the world [I]n the united States, most states make some use of hydroelectric power, although, as you can expect, states with low topographical relief, such as Florida and Kansas, produce very little hydroelectric power. But some states, such as Idaho, Washington, and oregon use hydroelec - tricity as their main power source. In 1995, all of Idaho’s power came from hydroelectric plants. china has developed large hydroelectric facilities in the last decade and now lead[s] the world in hydroelectricity usage. But, from north to south and from east to west, countries all over the world make use of hydroelectricity—the main ingredients are a large river and a drop in elevation.
Adapted from (no date). Hydroelectric Power Water Use. United States Geological Survey (USGS). Retrieved from http://ga.water.usgs.gov/edu/wuhy.html Building a tall dam allows water to fall from a great height, producing more energy. 1 As water flows in, it spins the turbine blades, generating a current from the coils of wire found in the generator. 2 The current then goes to the transformer, where the voltage travels over power lines to power homes and businesses. 3 ben85927_08_c08.indd 339 1/30/14 8:36 AM SEct Ion 8.2 Tradi Tional renewables—Hydropower and Geo TH ermal By National Renewable Energy Laboratory Geothermal Energy Many technologies have been developed to take advantage of geothermal energy—the heat from the earth. this heat can be drawn from several sources: hot water or steam reservoirs deep in the earth that are accessed by drilling; geothermal reservoirs located near the earth’s surface, mostly located in the western u.S., Alaska, and Hawaii; and the shallow ground near the Earth’s surface that maintains a relatively constant temperature of 508–608F.
this variety of geothermal resources allows them to be used on both large and small scales. A utility can use the hot water and steam from reservoirs to drive generators and produce elec - tricity for its customers. other applications apply the heat produced from geothermal directly to various uses in buildings, roads, agriculture, and industrial plants. Still others use the heat directly from the ground to provide heating and cooling in homes and other buildings.
Geothermal Direct Use geothermal reservoirs of hot water, which are found a few miles or more beneath the Earth’s surface, can be used to provide heat directly. this is called the direct use of geothermal energy. geothermal direct use has a long history, going back to when people began using hot springs for bathing, cooking food, and loosening feathers and skin from game. today, hot springs are still used as spas. But there are now more sophisticated ways of using this geothermal resource.
In modern direct-use systems, a well is drilled into a geothermal reservoir to provide a steady stream of hot water. the water is brought up through the well, and a mechanical system— piping, a heat exchanger, and controls—delivers the heat directly for its intended use. A dis - posal system then either injects the cooled water underground or disposes of it on the surface. geothermal hot water can be used for many applications that require heat. Its current uses include heating buildings (either individually or whole towns), raising plants in greenhouses, drying crops, heating water at fish farms, and several industrial processes, such as pasteur- izing milk.
Geothermal Electricity Production geothermal power plants use steam produced from reservoirs of hot water found a few miles or more below the Earth’s surface to produce electricity. the steam rotates a turbine that activates a generator, which produces electricity.
there are three types of geothermal power plants: dry steam, flash steam, and binary cycle. ben85927_08_c08.indd 340 1/30/14 8:36 AM SEct Ion 8.2 Tradi Tional renewables—Hydropower and Geo TH ermal Dry steam Dry steam power plants draw from underground resources of steam. the steam is piped directly from under- ground wells to the power plant where it is directed into a turbine/genera- tor unit. there are only two known underground resources of steam in the united States: the geysers in northern california and yellowstone national Park in Wyoming, where there’s a well- known geyser called old Faithful. Since yellowstone is protected from devel - opment, the only dry steam plants in the country are at the geysers. Flash steam Flash steam power plants are the most common and use geothermal res- ervoirs of water with temperatures greater than 360 8F (1828 c). this very hot water flows up through wells in the ground under its own pressure. As it flows upward, the pressure decreases and some of the hot water boils into steam. the steam is then sepa - rated from the water and used to power a turbine/generator. Any leftover water and con - densed steam are injected back into the reservoir, making this a sustainable resource.
Binary steam Binary cycle power plants operate on water at lower temperatures of about 225 8–3608F (107 8–182 8 c). Binary cycle plants use the heat from the hot water to boil a working fluid, usu - ally an organic compound with a low boiling point. the working fluid is vaporized in a heat exchanger and used to turn a turbine. the water is then injected back into the ground to be reheated. the water and the working fluid are kept separated during the whole process, so there are little or no air emissions.
Geothermal Heat Pumps geothermal heat pumps take advantage of the nearly constant temperature of the Earth to heat and cool buildings. the shallow ground, or the upper 10 feet of the Earth, maintains a temperature between 50 8 and 608F (108–168 c). this temperature is warmer than the air above it in the winter and cooler in the summer.
geothermal heat pump systems consist of three parts: the ground heat exchanger, the heat pump unit, and the air delivery system (ductwork). the heat exchanger is a system of pipes called a loop, which is buried in the shallow ground near the building. A fluid (usually water or a mixture of water and antifreeze) circulates through the pipes to absorb or relinquish heat within the ground.
In the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system. In the summer, the process is reversed, and the heat pump moves AP Photo/Calpine The only dry steam power plant in the United States, The Geysers, is located in the mountains of California. It has been tapping steam fields to produce power since the 1960s. ben85927_08_c08.indd 341 1/30/14 8:36 AM SEct Ion 8.3 nucl EA r Po WE r heat from the indoor air into the heat exchanger. the heat removed from the indoor air during the summer can also be used to heat water, providing a free source of hot water.
geothermal heat pumps use much less energy than conventional heating sys- tems, since they draw heat from the ground. they are also more efficient when cooling your home. not only does this save energy and money, it reduces air pollution.
All areas of the united States have nearly constant shallow-ground temperatures, which are suitable for geothermal heat pumps.
Adapted from (no date). Geothermal Energy Basics. National Renewable Energy Laboratory (NREL). Retrieved from http://www.nrel.gov/learning/re_geothermal.html 8.3 Nuclear Power The March 2011 earthquake and tsunami that triggered a catastrophe at Japan’s Fukushima nuclear complex has reignited debates over the role and safety of nuclear power. Because nuclear power can generate electricity without carbon dioxide emissions, it has been identified as a potentially useful way to meet our energy needs in a “climate-friendly” manner. However, concerns over nuclear safety, the disposal of highly radioactive nuclear waste, and the high cost of nuclear construction have hindered the development of this energy source. In this section, Dr. Helen Caldicott, a pediatrician in Australia and the founding president of Physicians for Social Responsibility, explains some of the outcomes of the nuclear crisis in Japan.
Most nuclear reactors, including the ones damaged by the tsunami in Japan, are based on the concept of nuclear fission. In nuclear fission, the nucleus of a heavy element such as uranium is bombarded with neutrons causing it to split apart and release multiple neutrons along with heat and radiation. The neutrons released in this process can go on and bombard other uranium atoms and create a chain reaction, releasing massive amounts of energy in the process. This is the basic idea behind a nuclear bomb. In a nuclear power plant, the chain reaction is controlled, and the heat released in the fission process is used to boil water and produce steam to spin a turbine and generate electricity.
Caldicott points out some of the health effects resulting from the catastrophe that occurred in Japan, indicating that nuclear power is the only form of energy that leaves so little room for error. Further updates and information on the Fukushima nuclear disaster are provided in the Additional resources section at the end of this chapter. Consider This Describe the basic difference between geo - thermal direct, geothermal electric, and geothermal heat pump systems. ben85927_08_c08.indd 342 1/30/14 8:36 AM SEct Ion 8.3 nucl EA r Po WE r By Helen Caldicott Nuclear Power No Answer to Climate Change Advocating nuclear power as an answer to global warming is analogous to prescribing smok- ing for weight loss.
nuclear reactors do not stand alone but rely on a massive industrial infrastructure using fos - sil fuel and other global warming gases. renewable energy that is readily available, cheaper than nuclear and coal, and can rapidly avert global warming must be immediately implemented by global governments.
let’s examine the Fukushima disaster—Australia’s uranium fuelled the reactors.
on March 11, 2011, three reactors were online when a massive earth- quake disrupted their power supply, drowned the auxiliary diesel genera- tors in the basements, and submerged pumps supplying each with 3.79 mil - lion litres of cooling water a minute.
Within hours, the intensely hot radio- active cores in units 1, 2 and 3 had started to melt—while the zirconium metal cladding on the uranium fuel rods reacted with water—generating hydrogen which forcefully exploded in buildings of 1, 2, 3 and 4, releasing huge amounts of radioactive elements into the air. And 400 tonnes of highly radioactive water—a total of 245,000 tonnes—has been leaking into the Pacific daily since the accident. three molten cores, each weighing more than 100 tonnes, melted their way through 15 centimetres of steel in the reactor vessels, now rest on concrete floors of the severely cracked containment buildings.
Each core contains as much radiation as that released by 1000 Hiroshima-sized bombs with more than 200 different radioactive elements, lasting seconds to millions of years.
Each of these deadly radioactive poisons has its own specific pathway in the food chain and the human body. radioactive elements are tasteless, odourless and invisible. It takes many years for cancers and other radiation-related diseases to manifest—from five to 80 years.
children are 10 to 20 times more radio-sensitive than adults, and foetuses thousands of times more so. Females are more sensitive than males. radiation is cumulative. there is no safe dose. Each dose adds to the risk of developing cancer. © Mainichi Newspaper/AFLO/AFLO/Nippon News/Corbis In March 2011, a large earthquake off the coast of Japan triggered a tsunami that breached the Tokyo Electric Power Company’s Fukushima Daiichi I power plant’s sea walls, crippling it. ben85927_08_c08.indd 343 1/30/14 8:36 AM SEct Ion 8.3 nucl EA r Po WE r radiation of the reproductive organs induces genetic mutations in the sperm and eggs, increasing the incidence of genetic diseases over future generations such as diabetes, cystic fibrosis, haemochromatosis and 6000 others.
Sea water beside Fukushima is highly contaminated with tritium, the highest level recorded.
tritium causes birth defects, cancers of various organs including brain and ovaries, testicular atrophy and mental retardation. tritium concentrates in food and fish and remains radioac - tive for 120 years . cesium, a potassium mimicker, concentrates in heart, endocrine organs and muscles where it induces cardiac irregularities, heart attacks, diabetes, hypothyroidism, thyroid cancer and rhabdomyosarcoma, a muscle cancer. cesium is radioactive for 300 years and concentrates in the food chain.
Strontium 90, poisonous for 300 years, is analogous to calcium, concentrating in grass and milk, then in bones, teeth and breast milk where it can cause bone cancer, leukaemia or breast cancer.
Plutonium lasts 240,000 years and is one of the most potent carcinogens—a millionth of a gram can cause cancer.
Plutonium resembles iron so it can induce cancers in the lung, liver, bone, testicle and ovary.
It crosses the placenta, causing severe birth deformities.
Each reactor core contains 150 kilograms of plutonium, and five kilograms is sufficient to make an atomic bomb. So nuclear power plants are essentially timeless bomb factories.
Iodine 131, radioactive for 100 days, is a potent carcinogen. Already 44 childhood thyroid cancers are suspected in Fukushima. thyroid cancer is extremely rare in young children. More than 350,000 children still live in highly radioactive areas. leukaemia and solid cancers of various organs will increase for the next 70 to 80 years in this generation. About 2 million people in Japan live in highly contaminated areas.
Food in the contaminated zone will be radioactive for hundreds of years as it concentrates radiation. So cancer will devastate many future Japanese generations.
Japanese doctors are reporting that they have been ordered not to tell patients that their problems are radiation related.
the levels of radiation in buildings 1, 2 and 3 are now so high humans cannot enter or get close to the molten cores. It will be impossible to remove these cores for hundreds of years— if ever.
Should one of these buildings collapse during another earthquake, the targeted flow of cooling water to the pools and cores would cease and the cores would become red hot, releasing massive amounts of radiation into the air and water. Fuel in five cooling pools could also ignite. ben85927_08_c08.indd 344 1/30/14 8:36 AM SEct Ion 8.4 En Ergy E FFI cIEncy Building 4 is severely damaged. A vul- nerable cooling pool situated on the roof contains 250 tonnes of very hot fuel rods which were removed from the reactor just before the earthquake struck. Although the rods and their holding racks are still intact, they are geometrically deformed due to the force of the hydrogen explo- sion and will be dangerous to remove.
A large earthquake disrupting the integrity of the building could cause it to collapse, taking down the pool. Zirconium cladding the rods would burn, releasing the equivalent of 14,000 Hiroshima-sized bombs and 10 times more cesium than chernobyl, polluting much of Japan and the northern hemisphere.
While atmospheric radiation will largely remain in the north, radioactive water and polluted fish will continue to migrate across the Pacific, affecting Hawaii, north America, South Amer - ica and, eventually, Australia. Caldicott, H. (2013, October 7). Nuclear power no answer to climate change. the Age. Retrieved from http://www .theage.com.au/comment/nuclear-power-no-answer-to-climate-change-2013100\ 7-2v3vu.html. Reprinted with permission. 8.4 Energy Efficiency Although much attention is focused on the potential for renewable energy sources such as solar and wind, relatively little consideration is given to the idea of energy efficiency. Energy efficiency can be defined as achieving the same outcome (lighting a room, driving a mile) while using less energy. The logic behind the pursuit of energy efficiency is simple: lowering energy demand through efficiency means reducing the need to produce energy in the first place—regardless of where that energy actually comes from. In the following reading, Eberhard K. Jochem of the Swiss Federal Institute of Technology provides examples of energy efficiency in action and sug - gests ways to boost the efficiency of energy use in the future.
Just as section 5.4 discussed reducing water demand as a means of addressing potential water shortages, energy efficiency focuses on the demand side of the equation rather than the supply side. Aggressive efforts to improve the efficiency of energy use in cars, homes, and businesses bring multiple benefits. Improved vehicle efficiency could reduce oil demand and decrease our dependence on foreign oil sources. More efficient use of electricity in homes and businesses could reduce the need to burn as much coal in power plants and reduce both local/regional air pollu- tion as well as greenhouse gas emissions .
However, there are economic and political barriers to more widespread adoption of energy effi - ciency measures. Because energy efficiency typically involves an upfront cost with payback over Consider This What are some of the major risks associ- ated with the use of nuclear power? How do these risks add to the cost of this form of energy? ben85927_08_c08.indd 345 1/30/14 8:36 AM SEct Ion 8.4 En Ergy E FFI cIEncy Consider This How much energy is lost in the conversion from primary energy to final energy and then on to useful energy? How does energy efficiency help to reduce these losses? time—for example, adding insulation to a home or installing new, energy-efficient windows— many homeowners and businesses hesitate or are unable to make such investments. Politically, energy efficiency does not seem as exciting as new energy sources like wind and solar, nor does it have a political lobby behind it the way fossil fuels do. These and other barriers can be over- come through policies such as tax incentives for energy-efficient investments and better label - ing of efficient appliances. Renewable energy sources are far more feasible and impactful when combined with energy efficiency efforts. We will see this clearly in section 8.5, which reviews a net-zero energy building that is so efficient it can easily meet its overall energy needs through renewable sources.
By Eberhard K. Jochem the huge potential of energy efficiency measures for mitigating the release of greenhouse gases into the atmosphere attracts little attention when placed alongside the more glamor - ous alternatives of nuclear, hydrogen or renewable energies. But developing a comprehensive efficiency strategy is the fastest and cheapest thing we can do to reduce carbon emissions. It can also be profitable and astonishingly effective, as two recent examples demonstrate.
From 2001 through 2005, Procter & gamble’s factory in germany increased production by 45 percent, but the energy needed to run machines and to heat, cool and ventilate buildings rose by only 12 percent, and carbon emissions remained at the 2001 level. the major pillars supporting this success include highly efficient illumination, compressed-air systems, new designs for heating and air conditioning, funneling heat losses from compressors into heating buildings, and detailed energy measurement and billing. In some 4,000 houses and build- ings in germany, Switzerland, Austria and Scandinavia, extensive insulation, highly efficient windows and energy-conscious design have led to enormous efficiency increases, enabling energy budgets for heating that are a sixth of the requirement for typical buildings in these countries. Improved efficiencies can be realized all along the energy chain, from the conver - sion of primary energy (oil, for example) to energy carriers (such as electricity) and finally to useful energy (the heat in your toaster). the annual global primary energy demand is 447,000 petajoules (a petajoule is roughly 300 gigawatt-hours), 80 percent of which comes from carbon-emitting fossil fuels such as coal, oil and gas. After conversion these primary energy sources deliver roughly 300,000 petajoules of so-called final energy to customers in the form of electricity, gasoline, heating oil, jet fuel, and so on.
the next step, the conversion of electric - ity, gasoline, and the like to useful energy in engines, boilers and lightbulbs, causes further energy losses of 154,000 pet- ajoules. thus, at present almost 300,000 petajoules, or two thirds of the primary energy, are lost during the two stages of energy conversion. Furthermore, all useful energy is eventually dissipated as heat at various temperatures. Insulating ben85927_08_c08.indd 346 1/30/14 8:36 AM SEct Ion 8.4 En Ergy E FFI cIEncy buildings more effectively, changing industrial processes and driving lighter, more aerody- namic cars would reduce the demand for useful energy, thus substantially reducing energy wastage.
given the challenges presented by climate change and the high increases expected in energy prices, the losses that occur all along the energy chain can also be viewed as opportu - nities—and efficiency is one of the most important. new technologies and know-how must replace the present intensive use of energy and materials.
Room for Improvement Because conservation measures, whether incorporated into next year’s car design or a new type of power plant, can have a dramatic impact on energy consumption, they also have an enormous effect on overall carbon emissions. In this mix, buildings and houses, which are notoriously inefficient in many countries today, offer the greatest potential for saving energy.
In countries belonging to the organization for Economic cooperation and Development (oEcD) and in the megacities of emerging countries, buildings contribute more than one third of total energy-related greenhouse gas emissions.
little heralded but impressive advances have already been made, often in the form of effi - ciency improvements that are invisible to the consumer. Beginning with the energy crisis in the 1970s, air conditioners in the u.S. were redesigned to use less power with little loss in cooling capacity and new u.S. building codes required more insulation and double-paned win - dows. new refrigerators use only one quarter of the power of earlier mod- els. (With approximately 150 million refrigerators and freezers in the u.S., the difference in consumption between 1974 efficiency levels and 2001 levels is equivalent to avoiding the genera - tion of 40 gigawatts at power plants.) changing to compact fluorescent light - bulbs yields an instant reduction in power demand; these bulbs provide as much light as regular incandescent bulbs, last 10 times longer and use just one fourth to one fifth the energy. . AlexMax/iStock/Thinkstock Replacing incandescent lightbulbs with energy- efficient alternatives, like compact fluorescent or LED bulbs, is one way to reduce energy consumption at work and home. ben85927_08_c08.indd 347 1/30/14 8:36 AM SEct Ion 8.4 En Ergy E FFI cIEncy Despite these gains, the biggest steps remain to be taken. Many buildings were designed with the intention of minimizing construction costs rather than life-cycle cost, including energy use, or simply in ignorance of energy-saving considerations. take roof overhangs, for exam - ple, which in warm climates traditionally measured a meter or so and which are rarely used today because of the added cost, although they would control heat buildup on walls and win - dows. one of the largest European manufacturers of prefabricated houses is now offering Apply Your Knowledge While a lot of attention gets paid to the potential for renewable energy sources like wind power and solar, relatively little is given to how energy efficiency and conservation can reduce our overall energy use. this is in large part due to the fact that most people have very little understanding of how they even use energy and how they might use it more efficiently. How - ever, there are dozens of websites available to help you estimate your own energy use and then find ways to reduce it. For example, explore the energy audit and calculator options at the sites listed below, the first focused on gasoline use and the remainder on electricity and natural gas:
http://www.learner.org/jnorth/tm/caribou/EnergyAudit.html —Work through the personal energy audit and fill in the missing figures on this page to get a sense of how much gasoline you are using annually. consider the “Journaling Questions” at the bot - tom of the page. listed below are home energy consumption calculators offered by various electric and gas utility companies in different regions of the u.S. Pick one of these and provide infor - mation on your appliance and device usage so as to calculate how much energy you are using. or, try completing two or more and see how the results compare. • http://www2.cmpco.com/Energy calculator/input.jsp • https://www.progress-energy.com/app/energycalculator/energycalculator.as\ px • http://www.cpsenergy.com/ residential/Information_ library/calculators.asp • https://www.pacificpower.net/res/sem/eeti/euc.html • http://www.cpi.coop/my-account/online-usage-calculator/ After completing these audits and calculations, visit the following web pages and briefly review the suggestions for using less energy: • http://energy.gov/sites/prod/files/energy_savers.pdf • http://www.alliantenergy.com/SaveEnergyAndMoney/ tipsforSavingEnergy/index .htm • http://www.pge.com/en/myhome/saveenergymoney/savingstips/index.page • http://www.energystar.gov/index.cfm?c=products.pr_save_energy_at_home What are three specific things that you can do to reduce your own energy use? Why aren’t you already doing these things? What are some reasons more people don’t practice energy efficiency? If you were put in charge of developing a public relations campaign to increase adoption of energy efficiency practices, what are some things you might do? ben85927_08_c08.indd 348 1/30/14 8:36 AM SEct Ion 8.4 En Ergy E FFI cIEncy zero-net-energy houses: these well-insulated and intelligently designed structures with solar-thermal and photovoltaic collectors do not need commercial energy, and their total cost is similar to those of new houses built to conform to current building codes. Because build- ings have a 50- to 100-year lifetime, efficiency retrofits are essential. But we need to coordi - nate changes in existing buildings thoughtfully to avoid replacing a single component, such as a furnace, while leaving in place leaky ducts and single-pane windows that waste much of the heat the new furnace produces. one example highlights what might be done in industry: although some carpet manufacturers still dye their products at 100 to 140 degrees celsius, others dye at room temperature using enzyme technology, reducing the energy demand by more than 90 percent.
The Importance of Policy to realize the full benefits of efficiency, strong energy policies are essential. Among the under - lying reasons for the crucial role of policy are the dearth of knowledge by manufacturers and the public about efficiency options, budgeting methods that do not take proper account of the ongoing benefits of long-lasting investments, and market imperfections such as external costs for carbon emissions and other costs of energy use. Energy policy set by governments has tra- ditionally underestimated the benefits of efficiency. of course, factors other than policy can drive changes in efficiency—higher energy prices, new technologies or cost competition, for instance. But policies—which include energy taxes, financial incentives, professional train- ing, labeling, environmental legislation, greenhouse gas emissions trading and international coordination of regulations for traded products—can make an enormous difference. Further - more, rapid growth in demand for energy services in emerging countries provides an opportunity to implement energy- efficient policies from the outset as infra - structure grows: programs to realize efficient solutions in buildings, transport systems and industry would give people the energy services they need without having to build as many power plants, refineries or gas pipelines.
Japan and the countries of the European union have been more eager to reduce oil imports than the u.S. has and have encouraged productivity gains through energy taxes and other measures. But all oEcD countries except Japan have so far failed to update appliance stan - dards. nor do gas and electric bills in oEcD countries indicate how much energy is used for heating, say, as opposed to boiling water or which uses are the most energy-intensive—that is, where a reduction in usage would produce the greatest energy savings. In industry, com- pressed air, heat, cooling and electricity are often not billed by production line but expressed as an overhead cost.
nevertheless, energy efficiency has a higher profile in Europe and Japan. A retrofitting project in ludwigshafen, germany, serves as just one example. Five years ago 500 dwellings were equipped to adhere to low-energy standards (about 30 kilowatt-hours per square meter per year), reducing the annual energy demand for heating those buildings by a factor of six. Consider This What are some of the most important barriers to more widespread adoption of energy efficiency? How can these barriers be overcome? ben85927_08_c08.indd 349 1/30/14 8:36 AM SEct Ion 8.5 Case His Tory— a Zero ener Gy offi Ce buildin G Before the retrofit, the dwellings were difficult to rent; now demand is three times greater than capacity.
other similar projects abound. the Board of the Swiss Federal Institutes of technology, for instance, has suggested a technological program aimed at what we call the 2,000-Watt Soci- ety—an annual primary energy use of 2,000 watts (or 65 gigajoules) per capita. realizing this vision in industrial countries would reduce the per capita energy use and related carbon emissions by two thirds, despite a two-thirds increase in gDP, within the next 60 to 80 years. Swiss scientists, including myself, have been evaluating this plan since 2002, and we have concluded that the goal of the 2,000-watt per capita society is technically feasible for indus- trial countries in the second half of this century.
to some people, the term “energy efficiency” implies reduced comfort. But the concept of efficiency means that you get the same service—a comfortable room or convenient travel from home to work—using less energy. the E u, its member states and Japan have begun to tap the substantial—and profitable—potential of efficiency measures. to avoid the rising costs of energy supplies and the even costlier adaptations to climate change, efficiency must become a global activity.
Adapted from Jochem, E. K. (2006, September). An Efficient Solution. Scientific American, 64–67. Reproduced with permission. Copyright © 2006 Scientific American, Inc. All rights reserved.
8.5 Case History—A Zero Energy Office Building Commercial buildings are a significant consumer of energy in our society and a major source of carbon dioxide emissions. In this article, Kirk Johnson of the new york times profiles a fas- cinating experiment in constructing a “net-zero energy” commercial office building. A net-zero building is designed to produce as much energy as it uses over the course of a day, week, month, Consider This the u.S. Department of Energy provides a wealth of information on energy efficiency and how you can save energy (and money) in your own home or apartment:
• http://energy.gov/public-services/homes/home-weatherization/home-energy-\ audits • http://energy.gov/videos/common-sense-and-next-30-seconds • http://www1.eere.energy.gov/multimedia/video_lighting_choices.html • http://www1.eere.energy.gov/multimedia/video_lumens.html • http://energy.gov/videos/energy-101-cool-roofs • http://energy.gov/videos/energy-101-daylighting • http://energy.gov/energysaver/articles/energy-efficient-home-design • http://energy.gov/public-services/homes/home-weatherization • http://energy.gov/public-services/homes/saving-electricity • http://energy.gov/public-services/homes/heating-cooling • http://energy.gov/public-services/homes/water-heating ben85927_08_c08.indd 350 1/30/14 8:36 AM SEct Ion 8.5 Case His Tory— a Zero ener Gy offi Ce buildin G or year. The National Renewable Energy Lab (NREL) building in Golden, Colorado, is designed to do just that. The building is first and foremost designed to be ultra energy efficient. Because even the most energy-efficient building still needs energy, it also incorporates renewable sources of energy, including a solar photovoltaic system, into its design. An interesting fact about this project is that it has been done using existing technologies and at a cost that is comparable to traditional building designs.
Many homes, offices, and other buildings built in the United States suffer from what is sometimes called a principal-agent problem. The principal-agent problem is when one person or business makes decisions that will have a large impact on energy consumption while another person or business actually pays the energy bills. Many home and office builders cut corners on energy- efficient features during construction in order to keep costs down. Likewise, they are unlikely to include any renewable energy features in construction. However, once the home or office is occupied, a different person has to live with and pay for these decisions. Some builders do invest in energy-efficient insulation, windows, and appliances, and they seek an “efficiency premium” in return, but they are in the minority. Another good example of the principal-agent problem is the landlord who refuses to improve the efficiency of an apartment in cases where the tenant has to pay the energy bills.
There was no principal-agent problem in the design and construction of the NREL building in Colorado. From start to finish energy efficiency and renewable energy were prime objectives of the project. A key insight provided by this and other zero energy projects is that the potential for renewable energy is greatly enhanced when renewable technologies are paired with energy efficiency. If a home or office building were energy inefficient it would require an enor- mous investment in solar panels or other renewable energy devices to meet energy demand. However, if energy demand can first be brought down by 30, 50, or 70 per - cent through efficiency measures, then a more modest investment in solar panels or other devices can meet the remaining demand for energy. Another key insight of this project is that if occupants of a build - ing are provided with real-time information on how their behaviors influence energy consump - tion, they will often modify those behaviors in ways that can save significant amounts of energy over time.
By Kirk Johnson the west-facing windows by Jim Duffield’s desk started automatically tinting blue at 2:50 p.m. on a recent Friday as the midwinter sun settled low over the rocky Mountain foothills.
Around his plant-strewn work cubicle, low whirring air sounds emanated from speakers in the floor, meant to mimic the whoosh of conventional heating and air-conditioning systems, neither of which his 222,000-square-foot office building has, or needs, even here at 5,300 feet elevation. the generic white noise of pretend ductwork is purely for background and work - place psychology—managers found that workers needed something more than silence. Consider This Define the principal-agent problem. How does it work to reduce or prevent invest - ments in energy efficiency? ben85927_08_c08.indd 351 1/30/14 8:36 AM SEct Ion 8.5 Case His Tory— a Zero ener Gy offi Ce buildin G Meanwhile, the photovoltaic roof array was beating a retreat in the fading, low-angled light.
It had until 1:35 p.m. been producing more electricity than the building could use—a three- hour energy budget surplus—interrupted only around noon by a passing cloud formation.
For Mr. Duffield, 62, it was just another day in what was designed, in painstaking detail, to be the largest net-zero energy office building in the nation. He’s still adjusting, six months after he and 800 engineers and managers and support staff from the national renewable Energy lab moved in to the $64 million building, which the federal agency has offered up as a tem - plate for how to do affordable, super-energy-efficient construction.
“It’s sort of a wonderland,” said Mr. Duffield, an administrative support worker, as the window shading system reached maximum.
Most office buildings are divorced, in a way, from their surroundings. Each day in the mechan - ical trenches of heating, cooling and data processing is much the same as another but for the cost of paying for the energy used. the energy lab’s research Support Facility building is more like a mirror, or perhaps a sponge, to its surroundings. From the light-bending window louvers [a window covering with adjust - able slats] that cast rays up into the interior office spaces, to the giant concrete maze in the sub-basement for holding and storing radiant heat, every day is completely different.
Collecting Data this is the story of one randomly selected day in the still-new building’s life: Jan. 28, 2011.
It was mostly sunny, above-average temperatures peaking in the mid-60s, light winds from the west-northwest. the sun rose at 7:12 a.m. By that moment, the central computer was already hard at work, tracking every watt in and out, seeking, always, the balance of zero net use over 24 hours—a goal that managers say probably won’t be attainable until early next year [2012], when the third wing of the project and a parking complex are completed.
With daylight, the building’s pulse quickened. the photovoltaic panels kicked in with electric - ity at 7:20 a.m.
As employees began arriving, electricity use—from cellphone chargers to elevators—began to increase. total demand, including the 65-watt maximum budget per workspace for all uses, lighting to computing, peaked at 9:40 a.m.
Meanwhile, the basement data center, which handles processing needs for the 300-acre cam- pus, was in full swing, peaking in electricity use at 10:10 a.m., as e-mail and research spread- sheets began firing through the circuitry.
For Mr. Duffield and his co-workers, that was a good-news bad-news moment: the data center is by far the biggest energy user in the complex, but also one of its biggest producers of heat, which is captured and used to warm the rest of the building. If there is a secret clubhouse for the world’s energy and efficiency geeks, it probably looks and feels just about like this. ben85927_08_c08.indd 352 1/30/14 8:36 AM SEct Ion 8.5 Case His Tory— a Zero ener Gy offi Ce buildin G “nothing in this building was built the way it usually is,” said Jerry Blocher, a senior project manager at Haselden construction, the general contractor for the project. the backdrop to everything here is that office buildings are, to people like Mr. Blocher, the unpicked fruit of energy conservation. commercial buildings use about 18 percent of the nation’s total energy each year, and many of those buildings, especially in years past, were designed with barely a thought to energy savings, let alone zero net use.
the answer at the research energy laboratory, a unit of the federal Department of Energy, is not gee-whiz science. there is no giant, expensive solar array that could mask a multitude of traditional design sins, but rather a rethinking of everything, down to the smallest elements, all aligned in a watt-by-watt march toward a new kind of building.
A Living Laboratory Managers even pride themselves on the fact that hardly anything in their building, at least in its individual component pieces, is really new. off-the-shelf technology, cost-effi - cient as well as energy-efficient, was the mantra to finding what designers repeatedly call the sweet spot—zero energy that doesn’t break a sweat, or the bank. More than 400 tour groups, from government agency planners to corporations to architects, have trouped through since the first employ - ees moved in last summer.
“It’s all doable technology,” said Jef- frey M. Baker, the director of labora - tory operations at the Department of Energy’s golden field office. “It’s a liv - ing laboratory.” Some of those techniques and tricks are as old as the great cathedrals of Europe (mass holds heat like a battery, which led to the concrete labyrinth in the subbasement). light, as builders since the pyramids have known, can be bent to suit need, with louvers that fling sunbeams to white panels over the office workers heads’ to minimize electricity use.
there are certainly some things that workers here are still getting used to. In nudg - ing the building toward zero net electricity over 24 hours, lighting was a main target. that forced designers to lower the partition walls between work cubicles to only 42 or 54 inches (height decided by compass, or perhaps sundial, in maximizing the flow of natural light and ventilation), which raised privacy concerns among workers. Even the managers’ offices have no ceilings—again to allow the flow of natural light, as cast from the ceiling. . Rick Wilking/Reuters/Corbis Solar tubes on the roof of the U.S. National Renewable Energy Laboratory Research Support Facility bring light deep into the building. Natural light provided by the solar tubes help the building achieve net-zero energy use. ben85927_08_c08.indd 353 1/30/14 8:36 AM SEct Ion 8.5 Case His Tory— a Zero ener Gy offi Ce buildin G Designing Green Behavior getting to the highest certification level in green building technology at reasonable cost also required an armada of creative decisions, large and small. the round steel structural columns that hold the building up? they came from 3,000 feet of natural gas pipe—built for the old energy economy and never used. the wood trim in the lobby? lodgepole pine trees—310 of them—killed by a bark beetle that has infested millions of acres of forest in the West.
ultimately, construction costs were brought in at only $259 a square foot, nearly $77 below the average cost of a new super-efficient commercial office building, according to figures from Haselden construction, the builder. other components of the design are based on observation of human nature.
People print less paper when they share a central printer that requires a walk to the copy room. People also use less energy, managers say, when they know how much they’re using. A monitor in the lobby offers real-time feedback on eight different measures.
the feedback comes right down to a worker’s computer screen, where a little icon pops up when the building’s central computer says conditions are optimal to crank the hand-opened windows. ( other windows, harder to reach, open by computer command.) Apply Your Knowledge one of the keys to developing an effective and efficient renewable energy economy is to know what forms of energy to develop where. large-scale development of solar energy facilities will make more sense in the sunny Southwest than it might in other regions, and wind and biomass are more readily available in some places than in others. this renewable energy map ( http:// www.nrdc.org/energy/renewables/energymap.asp ) developed by the natural resources Defense council ( nr Dc) shows existing renewable energy facilities on a state-by-state basis, as well as the potential for development of different forms of renewable energy. click on your state and review both the existing facilities and the potential for various renewable energy sources. next, review the following pages that provide detailed maps of the availability and potential for various renewable energy sources in different regions of the united States. • links to maps showing biomass, geothermal, solar, and wind energy potential: http:// www.nrel.gov/gis/maps.html • Information and maps on hydro-, wind, solar, geothermal, and biomass power: http:// www.nationalatlas.gov/articles/people/a_energy.html Based on a review of the nr Dc renewable energy map and the other sources of information, design a plan for your state to meet 100 percent of its energy requirements from renewable sources by the year 2050. What renewable energy sources feature most prominently in your plan and why? What role could energy efficiency play in achieving your goal? What kinds of policies would you put in place to make your plan achievable, and how would you present this plan to the public in order to gain their support? “the open office is different,” said Andrew Parker, an engineer. “ you want to be next to some - one quiet.” ben85927_08_c08.indd 354 1/30/14 8:36 AM Su MMA ry & rES ourc ES rethinking work shifts can also contribute. Here, the custodial staff comes in at 5 p.m., two or three hours earlier than in most traditional office buildings, saving on the use of lights.
the management of energy behavior, like the technology, is an experiment in progress.
“right now people are on their best behavior,” said ron Judkoff, a lab program manager. “ time will answer the question of whether you can really train people, or whether a coffee maker or something starts showing up.” Lessons Learned If Anthony castellano is a measure, the training regimen has clearly taken root. Mr. castellano, who joined the research laboratory last year as a Web designer after years in private industry, said the immersion in energy consciousness goes home with him at night.
“My kids are yelling at me because I’m turning off all the lights,” Mr. castellano said. At 5:05 p.m., the solar cells stopped producing. Declining daylight in turn produced a brief spike in lighting use, at 5:55 p.m. Five minutes later, the building management system began shutting off lights in a rolling two-hour cycle (the computer gives a few friendly blinks, as a signal in case a late-working employee wants to leave the lights on).
Mr. Duffield, whose work space is surrounded by a miniature greenhouse of plants he has brought, said his desk has become a regular stop on the group tours. If the building is a living experiment, he said, then his garden is the experiment within the experiment. co-workers stop by, joking in geek-speak about his plants, but also seriously checking up on them as a measure of building health.
“they refer to this as the building’s carbon sink,” he said. And Mr. Duffield’s babies—amaryllis, African violet, a pink trumpet vine—are very happy with all the refracted, reflected light they get, he said.
“the tropical trumpet vine in my house stops growing for the winter,” he said. “Here it has continued to grow, and when the days starting getting longer it might even bloom.” Adapted from Johnson, K. (2011). Soaking Up the Sun to Squeeze Bills to Zero. new york times. Retrieved from http://www.nytimes.com/2011/02/15/science/15building.html. © 2011 The New York Times. All rights reserved.
Used by permission and protected by the Copyright Laws of the United States. The printing, copying, redistribution, or retransmission of this Content without express written permission is prohibited. Summary & Resources chapter Summary Fossil fuels like oil, coal, and natural gas currently meet 80 percent of our energy require- ments. However, concerns about the political, economic, and environmental impacts of their use have increased interest in finding alternative energy sources. one possible approach would be to expand the use of nuclear power since this energy source emits less carbon diox - ide than fossil fuels. However, nuclear power comes with its own issues of safety, cost, waste ben85927_08_c08.indd 355 1/30/14 8:36 AM Su MMA ry & rES ourc ES storage, and the dangers of nuclear material getting into the hands of terrorists. It has been suggested that we are now in the early stages of an energy revolution or transition away from non-renewable fossil fuels, and that we are moving toward using more renewable forms of energy like solar and wind. Earlier energy transitions included the shift from wood and other forms of biomass to coal in the 19th century, as well as the rapid rise in the use of oil over the second half of the 20th century. Any significant shift from non-renewable to renewable energy sources will require changes in the way we produce and consume energy, and it will also require significant investment in new technologies and infrastructure.
this chapter began with a description of an ambitious plan to power the world with 100 per - cent renewable energy by 2030. the authors of that plan argue that while there are techni - cal and other challenges to be overcome to meet this goal, the main barrier is political. they suggest that if billions of dollars in subsidies for fossil fuels were eliminated and the external costs for these fuels were included in their price, then renewables would be highly competi- tive. However, because fossil fuel industries have enormous political clout, it might be difficult to implement policies to achieve this goal.
the chapter also made clear how important it is to improve the efficiency of energy use. If we can achieve the same outcome while using 20, 50, or even 80 percent less energy, then we can both save money and lower the environmental impact of our energy use. Achieving a signifi- cant shift from fossil fuels to renewable energy sources will be made that much easier if we are able to use energy more efficiently.
In the next chapter the focus shifts from climate change and energy to issues of pollution and waste management. the renewable energy sources described in this chapter not only have the potential to reduce greenhouse gas emissions, but they also help to address local and regional air pollution problems. Moreover, we’ll see that recycling and reuse of materials such as aluminum help to reduce the amount of energy required to produce the goods on which we depend. Working Toward Solutions there is no one, single international body that promotes or develops all of the various forms of renewable energy, although there are a number of organizations that promote specific types.
For example, the International renewable Energy Alliance ( http://baringo.invotech.se/), the International Solar Energy Society (http://www.ises.org/ ), and the World Wind Energy Association (http://www.wwindea.org/home/index.php ) all work to promote renewable energy at the international level. the International Hydropower Association ( http://www .hydropower.org/ ) and the International geothermal Association ( http://www.geothermal -energy.org/ ) promote these energy sources, while the International Atomic Energy Agency ( http://www.iaea.org/ ) serves as an intergovernmental forum on issues of nuclear power development and safety.
(continued) ben85927_08_c08.indd 356 1/30/14 8:36 AM Su MMA ry & rES ourc ES Working Toward Solutions (continued) globally, some countries are either more blessed with renewable energy resources or have been more aggressive in developing the renewable resources they have. World leaders in renewable energy development include germany and Denmark. Despite being far less sunny on average than the united States, germany has established itself as the number one producer of solar power in the world, producing five times as much as the u.S. ( http://www.washington post.com/blogs/wonkblog/wp/2013/02/08/germany-has-five-times-as-much-solar-power -as-the-u-s-despite-alaska-levels-of-sun/ ). germany combines its production of solar and wind power with high levels of energy efficiency in its homes, schools, and other buildings.
the germans first developed the concept of the “Passivhaus,” homes that are so energy effi - cient that they hardly require any energy for heating or cooling ( http://www.passivhaustrust.
org.uk/what_is_passivhaus.php). With thousands of miles of windy coastline, Denmark has emerged as one of the top wind power producers in the world and the country that gets the largest percentage of its energy needs from wind. Particularly interesting is the small island of Samso located in the geographic center of Denmark. Samso produces so much electricity from its wind turbines that it exports surplus power to the Danish mainland via underwater cables ( http://www.nytimes.com/2009/09/30/world/europe/30samso.html, http://www .cbsnews.com/8301-18563_162-2549273.html , and http://www.scientificamerican.com /article.cfm?id=samso-attempts-100-percent-renewable-power). Samso has been so success - ful at achieving energy independence that the island attracts thousands of visitors every year from all over the world to learn about how they did it. In the united States the federal government has a number of programs and policies in place to promote renewable energy and energy efficiency. For example, over the last three decades there have been at least 22 federal programs and provisions designed to boost the production and use of ethanol and biodiesel fuels, including mandates, tax incentives, and loan programs ( http://www.fas.org/sgp/crs/misc/ r40110.pdf ). While these programs have increased the production and use of these fuels, this effort has come under criticism for being less about the promotion of renewable energy and more about providing subsidies to farmers and large agribusiness companies ( http://www.fas.org/sgp/crs/misc/ r40155.pdf ). the national gov - ernment also provides more limited financial support to wind power, geothermal, wave/tidal power and other renewable energy sources through the Federal Production tax credit and the Investment tax credit ( http://pdf.wri.org/bottom_line_renewable_energy_tax_credits _10-2010.pdf ). these programs lower the tax liabilities of companies and investors who develop and deploy renewable energy facilities, lowering the cost of production and helping them be more competitive.
Besides these programs, the national renewable Energy laboratory ( nr El) of the u.S. Department of Energy (D oE) is the primary government center for research and development of renewable energy and energy efficiency (http://www.nrel.gov/ ). the nr El is based in golden, colorado, and was featured in the last reading of this chapter. the Energy Star Program ( http://www.energystar.gov/ ) was developed by the u.S. D oE and the Environmental Protec - tion Agency in the 1990s. It sets standards for energy efficiency in consumer products and appliances and advertises the energy efficiency of these products through its familiar label.
(continued) ben85927_08_c08.indd 357 1/30/14 8:36 AM Su MMA ry & rES ourc ES Post- test 1. Which of the following is not one of the policy options recommended to help speed up the adoption of renewable energy technologies? a. Implementation of a feed-in tariff b. t axing fossil fuels to reflect their externality costs c. Subsidizing corn ethanol production d. Investing in an improved long-distance power transmission system 2. It could be said that hydroelectric power is always renewable and always sustainable. a. t rue b. False 3. Which of the following is not a radioactive byproduct of nuclear power production? a. c esium-137 b. Plutonium c. Strontium-90 d. Bauxite Working Toward Solutions (continued) At a more local level, most states in the united States have developed some sort of renewable energy standard or goal. this interactive map from the center for climate and Energy Solu - tions (http://www.c2es.org/us-states-regions/policy-maps/renewable-energy-standards ) shows which states have standards and provides some basic information on those programs. non-governmentally, the American Wind Energy Association ( http://www.awea.org/ ), the American Solar Energy Society ( http://www.ases.org/), and the Biomass Power Association (http://www.usabiomass.org/ ) all work to promote these renewable energy resources. lastly, at an individual level, it might be difficult to imagine what one person can do to promote the development and use of renewable energy. However, these two tED talk videos tell the story of how a 14-year-old African boy built his family an electricity-generating windmill from spare parts based on a design he found in a book ( http://youtu.be/ g8yKFVP oD6o and http:// youtu.be/crj u5hu2fag ). More practically, individuals and organizations can support the devel- opment of renewable energy sources by purchasing some or all of their electricity from green power producers. this link ( http://www.ucsusa.org/clean_energy/what_you_can_do/buy -green-power.html) provides some information on how individuals can do this, while this link (http://www.epa.gov/greenpower/documents/purchasing_guide_for_web.pdf ) is a detailed document that organizations (such as schools, hospitals, and businesses) can make use of to decide whether and how to purchase green power. Finally, this chapter should have made clear that perhaps the most important thing individuals, organizations, and businesses can do is to first reduce their energy use through energy efficiency and conservation. this excellent guide from the Department of Energy (http://energy.gov/sites/prod/files/energy_savers.pd f) is loaded with tips for how to reduce your energy use and save money in the process. ben85927_08_c08.indd 358 1/30/14 8:36 AM Su MMA ry & rES ourc ES 4. Energy efficiency focuses more on the supply side than the demand side. a. t rue b. False 5. A “net-zero energy” building is designed to use no energy at all. a. t rue b. False 6. the authors estimate that solar power alone could produce more energy than what the world currently consumes. a. t rue b. False 7. the rate of hydroelectric dam construction in the united States has been increasing steadily in recent decades. a. t rue b. False 8. According to Amory lovins, the author of section 8.3, the kind of nuclear disaster that occurred in Japan in 2011 could never occur in the united States. a. t rue b. False 9. Which of the following BES t explains why so many buildings are energy inefficient? a. Building codes require inefficient design. b. Builders don’t have any information on efficient design. c. c onsumers demand inefficient buildings. d. Builders focus more on construction costs than on life-cycle costs. 10. Energy efficiency is improved in the national renewable Energy lab building in golden, colorado, by sending real-time updates on building conditions to workers’ computers. a. t rue b. False Answers 1. c. Subsidizing corn ethanol production. the answer can be found in section 8.1. 2. b. False. the answer can be found in section 8.2. 3. d. Bauxite. the answer can be found in section 8.3. 4. b. False. the answer can be found in section 8.4. 5. b. False. the answer can be found in section 8.5. 6. a. true. the answer can be found in section 8.1. 7. b. False. the answer can be found in section 8.2. 8. b. False. the answer can be found in section 8.3. 9. d. Builders focus more on construction costs than on life-cycle costs. the answer can be found in section 8.4. 10. a. true. the answer can be found in section 8.5. ben85927_08_c08.indd 359 1/30/14 8:36 AM Su MMA ry & rES ourc ES Key Ideas • large-scale, commercial solar and wind power facilities have the potential to meet a much larger share of our energy needs in the future. Some of the keys to making a transition from a largely fossil fuel-based economy to one powered by renewable energy such as solar and wind energy include changes to policy, better energy stor- age and distribution systems, and the removal of billions of dollars in subsidies to the fossil fuel industry. • Hydroelectric power or hydropower is electricity generated by the force of moving water, while geothermal energy takes advantage of heat from within the Earth. Both hydropower and geothermal energy are considered traditional forms of renew - able energy since they have been in widespread use for decades or even centuries.
Hydropower is a relatively clean form of energy since it does not depend on mining or combusting fossil fuels. However, construction of hydropower dams does disturb large land areas and can cause a variety of negative environmental impacts. geother - mal energy comes in a variety of forms and is also a relatively clean form of energy. • the March 2011 earthquake and tsunami in northern Japan triggered a massive catastrophe at the Fukushima nuclear power complex. that catastrophe has reig - nited debates over nuclear power and its future development. Supporters of nuclear power argue that it is a relatively clean form of energy and that isolated disasters like the one at Fukushima should not stop further development of this technology. opponents respond that nuclear power is not nearly as clean as renewable alterna - tives, that the risks of catastrophe are unacceptable, and that nuclear can only be supported economically through massive government subsidies. • Energy efficiency is achieving the same outcome—such as lighting or heating a room—while using less energy to do so. Energy efficiency helps reduce overall energy demand and, in the process, the environmental impacts of that energy use.
While energy efficiency can reduce environmental impact and lower energy bills, there are economic and political barriers to its more widespread adoption. consum - ers might hesitate to invest in the up-front costs necessary to achieve energy effi - ciency even if it will save them money over the long term. Politically, energy effi - ciency does not attract the same attention or interest as renewable and other forms of energy. • net-zero energy buildings are designed to produce as much energy as they con - sume. they achieve this energy self sufficiency by combining high levels of energy efficiency with on-site energy production by solar panels and other devices. the national renewable Energy laboratory building described in section 8.5 is the larg - est net-zero energy office building in the united States and was built for roughly the same cost as other commercial office buildings on a square foot basis. critical thinking and Discussion Questions 1. Much of the gasoline sold in the united States is blended with a small amount of corn-based ethanol. While this ethanol is considered a “renewable” energy source since it comes from corn, and corn can be constantly re-grown, many energy experts are skeptical of any environmental advantage from the widespread use of ethanol (see, for example, http://e360.yale.edu/feature/the_case_against_biofuels_probing _ethanols_hidden_costs/2251/ ). Why might this be the case? What is it about the way we currently grow corn, and convert that corn to ethanol, that make any ben85927_08_c08.indd 360 1/30/14 8:36 AM Su MMA ry & rES ourc ES environmental benefit from this fuel minimal? Why is it that despite the potential problems with corn-based ethanol this renewable energy form continues to receive generous government subsidies while subsidies for wind and solar power have been more difficult to secure? 2. on the surface, hydropower appears to offer a number of environmental advantages over electricity produced from burning coal or other fossil fuels. In particular, since hydropower does not involve any fossil fuel combustion, it does not directly emit greenhouse gases such as carbon dioxide into the atmosphere. However, recent scien- tific research ( http://www.newscientist.com/article/dn7046-hydroelectric-powers -dirty-secret-revealed.html ) suggests that hydropower projects in some locations, especially tropical regions, may be responsible for significant emissions of methane, a powerful greenhouse gas. this is because large-scale hydropower projects usually involve flooding large areas of land. If those lands were forested, the trees and other vegetation now under water will decompose and release methane gas in the process.
If you were a scientist tasked with estimating the methane emissions from a large- scale hydropower project before it gets built, what kind of experiment might you design to answer this question? How could you use this information to compare the relative greenhouse gas impacts of the hydropower project compared to a traditional coal-fired power plant? 3. Some people argue that the Fukushima nuclear accident in Japan was an isolated incident and that the same thing could not occur in the united States. Even if this were true (and there’s no way to know this), what are some of the other reasons many experts still oppose increased development of nuclear power? 4. one of the major barriers to greater adoption of energy efficiency approaches is that consumers don’t always take a long-term view of energy consumption and costs.
consider the following examples:
• a young couple with limited savings buys a “fixer-upper” house with drafty win - dows and poor insulation. they estimate that it would cost them roughly $4,000 to replace the windows and install adequate insulation. If they did these things they could save over $1,000 a year in heating costs, recouping their investment in roughly four years. • a retired couple on a fixed income is debating whether to replace their 20-year old refrigerator with a new, energy-efficient model that costs $1,000. They have been informed that the new refrigerator could save them $30 a month in electric bills or $360 a year, meaning they would recoup their investment in less than three years. Both of these examples present a case where it would make sense to pursue energy efficiency and save substantial amounts of money in the long term. However, both cases also describe a situation where the energy efficiency investments probably won’t be made due to the inability to afford the “up front” or initial investments.
What kind of policies or programs do you think could be used to change this situ - ation and help these couples make the right choice? How might programs like this be funded? How should they be communicated or advertised to the public? 5. the national renewable Energy laboratory net-zero energy building described in section 8.5 represents some of the best examples of “smart design” in building construction. the building is designed to allow natural light to provide most of the daytime illumination, for sunlight to provide heat in the winter and electricity throughout the year, and for its occupants to know when and how to adjust their behaviors to save energy. unfortunately, most of the buildings we live and work in ben85927_08_c08.indd 361 1/30/14 8:36 AM Su MMA ry & rES ourc ES externality cost the monetary value of health and environmental damage not factored into the price of a product such as fossil fuels.
life-cycle cost the sum of all recurring and one-time (non-recurring) costs over the full life span of a good, service, structure, or system.
light-water reactors A common nuclear reactor that uses water as a moderator and coolant. meltdown the melting of a nuclear reactor vessel causing the release of a substantial amount of radiation into the environment.
net-zero energy A building or installation that produces as much energy as it con - sumes and is considered to be energy self- sufficient or near self-sufficient. nuclear fission A nuclear reaction in which large atoms of certain elements are split into smaller atoms with the release of a large amount of energy. nuclear reactor A device that initiates and maintains a controlled nuclear fission chain reaction to produce electricity. photovoltaics Silicon-based energy cells that generate electricity when solar energy is absorbed; also called photovoltaic collectors. principal-agent problem A situation that occurs when someone makes a decision that impacts energy consumption and the cost is passed on to another person or business. renewable energy Energy generated from natural resources such as sunlight, wind, and water, which are naturally replenished. wind farm A power plant made up of a col - lection of wind turbines used for generating electricity; usually located in flat, wide open places where there is a constant breeze. wind turbine A mechanical device that uti - lizes the kinetic energy of wind by capturing it and converting it into electricity.
do not feature smart design. If anything, many of them could be characterized as “dumb design.” think about your own house or apartment, or the building in which you work or go to school. next, think about how energy is used to light, heat, cool, or provide power to devices in that building. can you find examples of smart design or dumb design? Are there features of the building that lead to unnecessary energy waste? Why do you think so many of the buildings in this country were built with so little thought or consideration for how they use energy? Key terms Additional resources In addition to the links provided in this section, there is additional information on the topics covered in this chapter in the Working Toward Solutions section.
the Federal Energy regulatory commission tracks energy infrastructure projects and pub - lishes regular reports on what percentage of our new energy systems come from various sources. their 2012 report ( http://www.ferc.gov/legal/staff-reports/dec-2012-energy -infrastructure.pdf ) was remarkable in that it illustrated that fully one-half of all new power generating capacity installed in the united States in 2012 was based on renewable energy ben85927_08_c08.indd 362 1/30/14 8:36 AM Su MMA ry & rES ourc ES resources. this can be seen by examining the breakdown by energy source in the table at the top of page 5.
A number of reports and articles in recent years have tried to examine the possibility of achieving close to 100 percent renewable energy in the decades ahead. • http://wwf.panda.org/what_we_do/footprint/climate_carbon_energy/energy _solutions22/renewable_energy/sustainable_energy_report/ • http://web.chem.ucsb.edu/~feldwinn/greenworks/ readings/solar_grand_plan.pdf • http://www.pewtrusts.org/uploadedFiles/wwwpewtrustsorg/ reports/ global _warming/ g20- report- low res.pdf • http://www.ucsusa.org/global_warming/solutions/reduce-emissions/climate -2030-blueprint.html • http://www.ucsusa.org/assets/documents/clean_energy/ ramping- up-renewables -Energy- you- can- count- on.pdf this very recent article by New York Times writer Elisabeth rosenthal explains why the transition to renewable energy may be happening sooner than many think (http://www.ny times.com/2013/03/24/sunday-review/life-after-oil-and-gas.html ) this article illustrates how the u.S. military and the Department of Defense are already leading the way in the devel - opment of renewable energy resources for strategic reasons ( http://www.motherjones.com /environment/2013/02/navy-climate-change-great-green-fleet). the Energy Information Administration provides some useful background information on a variety of renewable energy resources, including: • Hydroelectric power: http://www.eia.gov/energy_in_brief/article/hydropower.cfm and http://www.eia.gov/energyexplained/index.cfm?page=hydropower_home • Wind power: http://www.eia.gov/energy_in_brief/article/wind_power.cfm and http://www.eia.gov/energyexplained/index.cfm?page=wind_home • Biomass and biofuel energy: http://www.eia.gov/energyexplained/index.cfm? page=biomass_home and http://www.eia.gov/energyexplained/index.cfm?page =biofuel_home • geothermal energy: http://www.eia.gov/energyexplained/index.cfm?page =geothermal_home • Solar energy: http://www.eia.gov/energyexplained/index.cfm?page=solar_home the online news source Yale Environment 360 provides a literal wealth of information on all kinds of issues surrounding energy. this link takes you directly to their energy section: http://e360.yale.edu/topic/energy/015/ For more information on the Fukushima nuclear disaster in Japan, you can check out: • http://www.nature.com/news/specials/japanquake/fukushima.html • http://www.iaea.org/newscenter/news/tsunamiupdate01.html • http://energy.gov/situation-japan-updated-12513 this link provides a brief update of the status of the nuclear industry in the united States. (http://www.eia.gov/energy_in_brief/article/nuclear_industry.cfm). A somewhat supportive ben85927_08_c08.indd 363 1/30/14 8:36 AM Su MMA ry & rES ourc ES report on the future of nuclear power was published by a group out of MI t (http://web .mit.edu/nuclearpower/pdf/nuclearpower-summary.pdf ), while the union of concerned Sci - entists represents a group opposed to nuclear power on safety, environmental, and economic grounds (http://www.ucsusa.org/nuclear_power/ ). Amory lovins expands on his argu - ments against nuclear power in a piece titled “ the nuclear Illusion” ( http://www.rmi.org /Knowledge- center/ library/E08-01_ nuclearIllusion ). At the international level, this report argues that nuclear power and renewables are not really compatible, and that society should make a clear choice in favor of one path or another ( http://www.boell.eu/downloads /froggatt_schneider_systems_for_change.pdf ).
An interesting way to promote energy efficiency is through the use of social psychology as explained in this story from Yale Environment 360 (http://e360.yale.edu/feature/how_data _and_social_pressure_can_reduce_home_energy_use/2597/ ). one of the most comprehensive reports on energy efficiency in the united States was by the McKinsey global Energy and Materials group ( http://www.mckinsey.com/client_service/electric_power_and_natural_gas /latest_thinking/unlocking_energy_efficiency_in_the_us_economy ). the u.S. Water Power Program helps to develop technologies to harness the power of water not only through traditional hydropower but also through waves and tides (http:// www1.eere.energy.gov/water/ ). tidal power and wave power are also explained in a little more detail here ( http://education.nationalgeographic.com/education/encyclopedia/tidal -energy/?ar_a=1 ) and here (http://www.alternative-energy-news.info/technology/hydro /wave-power/ ). A form of biomass energy known as biogas is described in some detail here (http://www.afdc.energy.gov/fuels/emerging_biogas.html ) and here (http://biogas.ifas.ufl .edu/).
lastly, here are two great sources that provide a lot of information on the problems and chal - lenges associated with our conventional energy system and the promises and possibilities for a renewable energy future (http://earththeoperatorsmanual.com/landing/watch-share ) and (http://burnanenergyjournal.com/apm-station-info/ ). ben85927_08_c08.indd 364 1/30/14 8:36 AM