Chapter 08(3)

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8Sarah Leen/National Geographic Stock

Renewable and Nuclear Energy

Topics Discussed

NewRenewablesSolar,Wind,andBiofuels

TraditionalRenewablesHydropowerandGeo-

thermal

NuclearPower EnergyEfficiency

CaseHistoryAZeroEnergyOfficeBuilding

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CHAPTER 8Section 8.1 New RenewablesSolar, Wind, and Biofuels

Walk around your home and take note of all of the devices that you leave plugged inwhether or not they are in use. Televisions, computers, refrigerators, alarm clocks, andcell phone chargers all constantly use energy. Next, try to imagine the sum of such energyconsumption that occurs in the more than 100 million households across the entire UnitedStates. Add to it all of the electricity, home and commercial heating and cooling, manu-

facturing, and fuel used to power various methods of transportation. Now, still in yourimagination, expand this sum of consumption to include all the other countries through-out the world.

The staggering sum of energy consumption across the world has been quantified by theEnergy Information Agency (EIA) of the United States. The EIA estimates that worldenergy consumption was approximately 500 quadrillion Btu [British thermal unit] in 2010(U.S. Energy Information Administration, 2010). Its difficult to attach a human scale tothis number. 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 thatglobal consumption will increase by about 1 times the current measurement.

When we look into the future, we face the certainty that fossil fuel reserves will becomedepleted. Indeed, in 2010 about 90% of global energy supply was furnished by fossil fuels(BP, 2010). Experts agree that alternative energy sources must be explored in order keepup with global energy demands and avoid catastrophic climate changes. Not surprisingly,though, experts also argue over whether with sufficient will and investment, we can andwill convert to a renewable and nuclear energy economy without a significant changein our lifestyles. In this chapter we will examine the risks and rewards of using nuclearenergy sources, as well as explore the plausibility of using various renewable energysources as we seek the answer to the following question: Can the global society makethe massive shift to using windmills, solar panels, and other renewable energy sources,coupled with nuclear power, to replace the current reliance on fossil fuels?

8.1New RenewablesSolar, Wind, and Biofuels

In this reading, Daniel Kammen of the University of California, Berkeley, reviews the potential forthree relatively new forms of renewable energysolar power, wind power, and biofuels for trans-portation. Currently, all three of these technologies only meet a small portion of our energy needs;however, their use is growing rapidly. As further technological progress continues to reduce thecosts of using these renewables, their use will become even more widespread. Renewable energysources offer numerous benefits, including that they can be produced domestically, they never runout, and they generate very little local air pollution or greenhouse gas emissions.

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 sunlightis used to illuminate or heat interior spaces. Active solar energy captures sunlight using mechani-cal devices and then converts it to useful heat or electric power. Solar photovoltaic or PV panelsconvert sunlight to electricity, which is the most common form of active solar energy. You can findPV panels on solar calculators, rooftops, and streetlights and traffic signs. Another way to generateelectricity using solar energy is through solar thermal or concentrating solar power (CSP) systems.

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renewableenergy:

energy generated

from natural resources

such as sunlight, wind,

and water, which are

naturally replenished

These systems use mirrors to concentrate the suns rays on a tank or pipe filled with fluid. Theheated fluid can then be used to produce steam used to spin a turbine to generate electricity.

Another type of popular renewable energy source comes from the use of wind turbines, which aremechanical 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 Germany, Spain, the UnitedStates, and China. In terms of percentage share of total energy Denmark is the world leader withmore than 20% of their electricity needs produced from wind power. Denmark uses wind turbineslocated both on land and in offshore regions near the coast. Such offshore areas have stronger andmore consistent winds but are also more expensive to develop.

Lastly, the renewable energy that is biofuels refers to liquid fuels produced from plant material. Themost common biofuel utilized by Americans is ethanol, which is blended with the gasoline that issold in many states. Ethanol is produced by fermenting grains such as corn, but because this pro-cess diverts corn from food uses, its production has been implicated in food price increases in recentyears. In addition, producing corn-based ethanol actually requires a significant investment of fossilfuels to provide heat for the fermentation process, and so ethanol may not actually displace much in

the way of fossil fuels or help reduce greenhouse gas emissions. Ethanol produced from other plantmaterial besides corn and other grainsknown as cellulosic ethanolhas greater environmentalbenefits. However, cellulosic ethanol is not yet commercially viable as a fuel source.

Kammen argues that in order to further develop these renewable energy sources and speed up theenergy transition away from fossil fuels two things have to happen. First, we need to continue toinvest in the research and development of alternative energy sources to bring their price down. Sec-ond, energy prices need to reflect their true costs of production and use, including the hidden envi-ronmental costs associated with the use of fossil fuels. Such true cost pricing would make renewableenergies even more competitive and drive greater investment in their development and use.

ByDanielKammen

No plan to substantially reduce greenhouse gas emissions cansucceed through increases in energy efficiency alone. Becauseeconomic growth continues to boost the demand for energy

more coal for powering new factories, more oil for fueling new cars,more natural gas for heating new homescarbon emissions will keepclimbing despite the introduction of more energy-efficient vehicles, buildings, and appliances. To counter the alarming trend of globalwarming, the United States and other countries must make a majorcommitment to developing renewable energy sources that generatelittle or no carbon.

Renewable energy technologies were suddenly and briefly fashionable three decades agoin response to the oil embargoes of the 1970s, but the interest and support were not sus-tained. In recent years, however, dramatic improvements in the performance and afford-ability of solar cells, wind turbines and biofuelsethanol and other fuels derived fromplantshave paved the way for mass commercialization. In addition to their environ-mental benefits, renewable sources promise to enhance Americas energy security byreducing the countrys reliance on fossil fuels from other nations. What is more, high and

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photovoltaics: silicon-

based energy cells that

generate electricity

when solar energy is

absorbed; also called

photovoltaic collectors

wildly fluctuating prices for oil and natural gas have made renewable alternatives moreappealing.

We are now in an era where the opportunities for renewable energy are unprecedented,making this the ideal time to advance clean power for decades to come. But the endeavor

will require a long-term investment of scientific, economic, and political resources. Poli-cymakers and ordinary citizens must demand action and challenge one another to hastenthe transition.

Letthesunshine

Solar cells, also known as photovoltaics, use semiconductor materials to convert sunlightinto electric current. They now provide just a tiny slice of the worlds electricity: their globalgenerating capacity of 5,000 megawatts (MW) is only 0.15 percent of the total generating

capacity from all sources. Yet sunlight could potentially supply 5,000times as much energy as the world currently consumes. And thanks

to technology improvements, cost declines and favorable policies inmany states and nations, the annual production of photovoltaics hasincreased by more than 25 percent a year for the past decade and by aremarkable 45 percent in 2005. The cells manufactured last year added1,727 MW to worldwide generating capacity, with 833 MW made inJapan, 353 MW in Germany and 153 MW in the U.S.

Solar cells can now be made from a range of materials, from the traditional multicrystal-line silicon wafers that still dominate the market to thin-film silicon cells and devicescomposed of plastic or organic semiconductors. Thin-film photovoltaics are cheaper toproduce than crystalline silicon cells but are also less efficient at turning light into power.In laboratory tests, crystalline cells have achieved efficiencies of 30 percent or more; cur-

rent commercial cells of this type range from 15 to 20 percent. Both laboratory and com-mercial efficiencies for all kinds of solar cellshave risen steadily in recent years, indicatingthat an expansion of research efforts would fur-ther enhance the performance of solar cells onthe market.

Solar photovoltaics are particularly easy to usebecause they can be installed in so many placeson the roofs or walls of homes and office build-ings, in vast arrays in the desert, even sewn intoclothing to power portable electronic devices.The state of California has joined Japan and Ger-many in leading a global push for solar instal-lations; the Million Solar Roof commitment isintended to create 3,000 MW of new generatingcapacity in the state by 2018. Studies done by myresearch group, the Renewable and AppropriateEnergy Laboratory at the University of Califor-nia, Berkeley, show that annual production of

Gary Braasch

Many experts are confident that sources of

renewable energy, such as the solar thermal

power plant in the Mojave Desert, offer an

opportunity to transition away from fossil

fuels.

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solar photovoltaics in the U.S. alone could grow to 10,000 MW in just 20 years if currenttrends continue.

The biggest challenge will be lowering the price of the photovoltaics, which are now rela-tively expensive to manufacture. Electricity produced by crystalline cells has a total cost of

20 to 25 cents per kilowatt-hour, compared with four to six cents for coal-fired electricity,five to seven cents for power produced by burning natural gas, and six to nine cents forbiomass power plants. (The cost of nuclear power is harder to pin down because expertsdisagree on which expenses to include in the analysis; the estimated range is two to 12cents per kilowatt-hour.) Fortunately, the prices of solar cells have fallen consistently overthe past decade, largely because of improvements in manufacturing processes. In Japan,where 290 MW of solar generating capacity were added in 2005 and an even larger amountwas exported, the cost of photovoltaics has declined 8 percent a year; in California, where50 MW of solar power were installed in 2005, costs have dropped 5 percent annually.

Surprisingly, Kenya is the global leader in the number of solar power systems installedper capita (but not the number of watts added). More than 30,000 very small solar panels,

each producing only 12 to 30 watts, are sold in that country annually. For an investmentof as little as $100 for the panel and wiring, the system can be used to charge a car battery,which can then provide enough power to run a fluorescent lamp or a small black-and-white television for a few hours a day. More Kenyans adopt solar power every year thanmake connections to the countrys electric grid. The panels typically use solar cells madeof amorphous silicon; although these photovoltaics are only half as efficient as crystallinecells, their cost is so much lower (by a factor of at least four) that they are more affordableand useful for the two billion people worldwide who currently have no access to electric-ity. Sales of small solar power systems are booming in other African nations as well, andadvances in low cost photovoltaic manufacturing could accelerate this trend.

Furthermore, photovoltaics are not the only fast-growing form of solar power. Solar-ther-mal systems, which collect sunlight to generate heat, are also undergoing a resurgence.These systems have long been used to provide hot water for homes or factories, but theycan also produce electricity without the need for expensive solar cells. In one design, forexample, mirrors focus light on a Stirling engine, a high efficiency device containing aworking fluid that circulates between hot and cold chambers. The fluid expands as thesunlight heats it, pushing a piston that, in turn, drives a turbine.

In the fall of 2005 a Phoenix company called Stirling Energy Systems announced thatit was planning to build two large solar-thermal power plants in southern California.The company signed a 20-year power purchase agreement with Southern California Edi-son, which will buy the electricity from a 500-MW solar plant to be constructed in the

Mojave Desert. Stretching across 4,500 acres, the facility will include 20,000 curved dishmirrors, each concentrating light on a Stirling engine about the size of an oil barrel. Theplant is expected to begin operating in 2009 and could later be expanded to 850 MW.Stirling Energy Systems also signed a 20-year contract with San Diego Gas & Electric tobuild a 300-MW, 12,000-dish plant in the Imperial Valley. This facility could eventually beupgraded to 900 MW.

The financial details of the two California projects have not been made public, but electric-ity produced by present solar-thermal technologies costs between five and 13 cents per

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windturbine: a

mechanical device

that utilizes the

kinetic energy of

wind by capturing it

and converting it into

electricity

windfarm: a power

plant made up of a

collection of wind

turbines used for

generating electricity;usually located in flat,

wide open places where

there is a constant

breeze

kilowatt-hour, with dish-mirror systems at the upper end of that range. Because the proj-ects involve highly reliable technologies and mass production, however, the generationexpenses are expected to ultimately drop closer to four to six cents per kilowatt-hourthat is, competitive with the current price of coal-fired power.

Blowinginthewind

Wind power has been growing at a pace rivaling that of the solarindustry. The worldwide generating capacity of wind turbines hasincreased more than 25 percent a year, on average, for the past decade,reaching nearly 60,000 MW in 2005. The growth has been nothingshort of explosive in Europebetween 1994 and 2005, the installedwind power capacity in European Union nations jumped from 1,700to 40,000 MW. Germany alone has more than 18,000 MW of capacitythanks to an aggressive construction program. The northern Germanstate of Schleswig-Holstein currently meets one quarter of its annual

electricity demand with more than 2,400 windturbines, and in certain months wind powerprovides more than half the states electricity. Inaddition, Spain has 10,000 MW of wind capacity,Denmark has 3,000 MW, and Great Britain, theNetherlands, Italy and Portugal each have morethan 1,000 MW.

In the U.S. the wind power industry has accel-erated dramatically in the past five years, withtotal generating capacity leaping 36 percent to9,100 MW in 2005. Although wind turbines now

produce only 0.5 percent of the nations elec-tricity, the potential for expansion is enormous,especially in the windy Great Plains states.(North Dakota, for example, has greater windenergy resources than Germany, but only 98MW of generating capacity is installed there.) Ifthe U.S. constructed enough wind farms to fully

tap these resources, the turbines could generate as much as 11 trillionkilowatt-hours of electricity, or nearly three times the total amountproduced from all energy sources in the nation last year. The windindustry has developed increasingly large and efficient turbines, eachcapable of yielding 4 to 6 MW. And in many locations, wind power isthe cheapest form of new electricity, with costs ranging from four toseven cents per kilowatt-hour.

The growth of newwind farms in the U.S. has been spurred by aproduction tax credit that provides a modest subsidy equivalent to1.9 cents per kilowatt-hour, enabling wind turbines to compete withcoal-fired plants. Unfortunately, Congress has repeatedly threatened

Gary Braasch

Between 2000 and 2010, world wind

electric generating capacity increased at

a frenetic pace from 17,000 megawatts

to nearly 200,000 megawatts, says Earth

Policy Institutes Lester Brown.

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biofuels: gas or liquid

fuel made from plant

material

to eliminate the tax credit. Instead of instituting a long-term subsidy for wind power, thelawmakers have extended the tax credit on a year-to-year basis, and the continual uncer-tainty has slowed investment in wind farms. Congress is also threatening to derail a pro-posed 130-turbine farm off the coast of Massachusetts that would provide 468 MW of gen-erating capacity, enough to power most of Cape Cod, Marthas Vineyard and Nantucket.

The reservations about wind power come partly from utility companies that are reluctantto embrace the new technology and partly from so-called NIMBY-ism. (NIMBY is anacronym for Not in My Backyard.) Although local concerns over how wind turbines willaffect landscape views may have some merit, they must be balanced against the socialcosts of the alternatives. Because societys energy needs are growing relentlessly, rejectingwind farms often means requiring the construction or expansion of fossil fuelburningpower plants that will have far more devastating environmental effects.

Greenfuels

Researchers are also pressing ahead with the development of biofuelsthat could replace at least a portion of the oil currently consumed bymotor vehicles. The most common biofuel by far in the U.S. is ethanol,which is typically made from corn and blended with gasoline. Themanufacturers of ethanol benefit from a substantial tax credit: withthe help of the $2-billion annual subsidy, they sold more than 16 bil-lion liters of ethanol in 2005 (almost 3 percent of all automobile fuel byvolume), and production is expected to rise 50 percent by 2007. Some policymakers havequestioned the wisdom of the subsidy, pointing to studies showing that it takes moreenergy to harvest the corn and refine the ethanol than the fuel can deliver to combustionengines. In a recent analysis, though, my colleagues and I discovered that some of thesestudies did not properly account for the energy content of the by-products manufactured

along with the ethanol. When all the inputs and outputs were correctly factored in, wefound that ethanol has a positive net energy ofalmost five megajoules [a unit of measurementof energy equal to one million joules] per liter.

We also found, however, that ethanols impacton greenhouse gas emissions is more ambigu-ous. Our best estimates indicate that substitutingcorn-based ethanol for gasoline reduces green-house gas emissions by 18 percent, but the anal-ysis is hampered by large uncertainties regard-ing certain agricultural practices, particularlythe environmental costs of fertilizers. If we usedifferent assumptions about these practices, theresults of switching to ethanol range from a 36percent drop in emissions to a 29 percent increase.Although corn-based ethanol may help the U.S.reduce its reliance on foreign oil, it will probablynot do much to slow global warming unless theproduction of the biofuel becomes cleaner.

Sarah Leen/National Geographic Stock

This biomass facility in an agricultural

region in California, burns rice crop waste

to generate electricity. More and more,

crop wastes are being looked at as potential

sources of fuel.

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Fischer-Tropsch

process: a set of

chemical reactions that

convert a mixture of

carbon monoxide and

hydrogen into liquid

hydrocarbons that can

be used as fuel

But the calculations change substantially when the ethanol is made from cellulosic sources:woody plants such as switchgrass or poplar. Whereas most makers of corn-based ethanolburn fossil fuels to provide the heat for fermentation, the producers of cellulosic ethanolburn ligninan unfermentable part of the organic materialto heat the plant sugars.Burning lignin does not add any greenhouse gases to the atmosphere, because the emis-

sions are offset by the carbon dioxide absorbed during the growth of the plants used tomake the ethanol. As a result, substituting cellulosic ethanol for gasoline can slash green-house gas emissions by 90 percent or more.

Another promising biofuel is so-called green diesel. Researchers haveproduced this fuel by first gasifying biomassheating organic mate-rials enough that they release hydrogen and carbon monoxideandthen converting these compounds into long-chain hydrocarbonsusing the Fischer-Tropsch process. (During World War II, Germanengineers employed these chemical reactions to make synthetic motorfuels out of coal.) The result would be an economically competitiveliquid fuel for motor vehicles that would add virtually no greenhouse

gases to the atmosphere. Oil giant Royal Dutch/Shell is currentlyinvestigating the technology.

Policiestopromotenewrenewables

Each of these renewable sources is now at or near a tipping point, the crucial stage wheninvestment and innovation, as well as market access, could enable these attractive butgenerally marginal providers to become major contributors to regional and global energysupplies. At the same time, aggressive policies designed to open markets for renew-ables are taking hold at city, state and federal levels around the world. Governmentshave adopted these policies for a wide variety of reasons: to promote market diversity

or energy security, to bolster industries and jobs, and to protect the environment on boththe local and global scales. In the U.S. more than 20 states have adopted standards settinga minimum for the fraction of electricity that must be supplied with renewable sources.Germany plans to generate 20 percent of its electricity from renewables by 2020, and Swe-den intends to give up fossil fuels entirely.

But perhaps the most important step toward creating a sustainable energy economy is toinstitute market-based schemes to make the prices of carbon fuels reflect their social cost.The use of coal, oil and natural gas imposes a huge collective toll on society, in the form ofhealth care expenditures for ailments caused by air pollution, military spending to secureoil supplies, environmental damage from mining operations, and the potentially devas-tating economic impacts of global warming. A fee on carbon emissions would provide asimple, logical and transparent method to reward renewable, clean energy sources overthose that harm the economy and the environment. The tax revenues could pay for someof the social costs of carbon emissions, and a portion could be designated to compensatelow-income families who spend a larger share of their income on energy. Furthermore,the carbon fee could be combined with a cap-and-trade program that would set limitson carbon emissions but also allow the cleanest energy suppliers to sell permits to theirdirtier competitors. The federal government has used such programs with great successto curb other pollutants, and several northeastern states are already experimenting withgreenhouse gas emissions trading.

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CHAPTER 8Section 8.2 Traditional RenewablesHydropower and Geothermal

Best of all, these steps would give energy companies an enormous financial incentive toadvance the development and commercialization of renewable energy sources. In essence, theU.S. has the opportunity to foster an entirely new industry. The threat of climate change canbe a rallying cry for a clean-technology revolution that would strengthen the countrys manu-facturing base, create thousands of jobs and alleviate our international trade deficitsinstead

of importing foreign oil, we can export high-efficiency vehicles, appliances, wind turbinesand photovoltaics. This transformation can turn the nations energy sector into somethingthat was once deemed impossible: a vibrant, environmentally sustainable engine of growth.

Adapted from Kammen, D. M. (2006). The Rise of Renewable Energy. Scientific American, September: 8493.

Reproduced with permission. Copyright 2006 Scientific American, Inc. All rights reserved.

8.2Traditional RenewablesHydropower and Geothermal

Decades before modern solar panels and wind turbines were developed, we used the energy con-

tained in running water and under the Earths surface. Water-generated energy called hydroelec-tric power or hydropower taps the kinetic energy of moving water to generate electricity. For overa century dams have been built in the United States to exploit this energy resource. Geothermalpower makes use of heated water that is deep underground to produce steam to generate electric-ity. Because the water cycle keeps water moving, and because the geologic conditions that produceunderground hot water and steam will continue to do so indefinitely, hydropower and geothermalpower 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 fuelcombustion and 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 waterin place, it can have a number of ecological and social impacts. These include the destruction ofwildlife habitat and homes as well as modification of river flow patterns.

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 providehot 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 underground nearlyeverywhere can be tapped to heat and cool homes and buildings. Such geothermal heat pump sys-tems make use of the relatively constant temperature of 50 to 60 F just ten feet below the surfaceto cool spaces in the summer and heat them in the winter.

BytheUnitedStatesGeologicalSurvey

Hydropower

Although most energy in the United States is produced by fossil-fuel and nuclearpower plants, hydroelectricity is still important to the Nation, as about 7 percent oftotal power is produced by hydroelectric plants. Nowadays, huge power genera-

tors are placed inside dams. Water flowing through the dams spin turbine blades whichare connected to generators. Power is produced and is sent to homes and businesses.

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World distribution of hydropower

Hydropower is the most important andwidely-used renewable source of energy.

Hydropower represents 19% of totalelectricity production.

China is the largest producer of hydro-electricity, followed by Canada, Brazil,and the United States (Source: EnergyInformation Administration).

Approximately two-thirds of the economicallyfeasible potential remains to be developed.Untapped hydro resources are still abundant inLatin America, Central Africa, India and China.

Producing electricity using hydroelectric power

has some advantages over otherpower-producingmethods. Lets do a quick comparison:

Advantages to hydroelectric power:

Fuel is not burned so there is minimalpollution

Water to run the power plant is pro-vided 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

Its renewablerainfall renews the water in the reservoir, so the fuel is almost alwaysthere.

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 modification 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

Walter Meayers Edwards/National Geographic Stock

While Glen Canyon Dam provides abundant

electricity to major cities of the American

West, it has had considerable impacts

on the Colorado River ecosystem. Before

the dams construction, the section of

river below Glen Canyon contained silty,

warmer water, favoring native fish such ashumpback chub and razorback sucker. Since

the dams completion, water below the

dam tends to be colder and to favor trout.

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Hydropower and the environment

Hydropower is nonpolluting, but does have environmental impacts

Hydropower does not pollute the water or the air. However, hydropower facilities canhave 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 obstructfish migration and affect their populations. Operating a hydroelectric power plant mayalso change the water temperature and the rivers flow. These changes may harm nativeplants and animals in the river and on land. Reservoirs may cover peoples homes, impor-tant natural areas, agricultural land, and archeological sites. So building dams can requirerelocating people. Methane, a strong greenhouse gas, may also form in some reservoirsand be emitted to the atmosphere.

Reservoir construction is drying up in the United States

[H]ydroelectric power sounds greatso why dont 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 andreservoir, which all takes a LOT of money, time, and construction. In fact, most of thegood spots to locate hydro plants have already been taken. In the early part of the centuryhydroelectric plants supplied a bit less than one-half of the nations power, but the num-ber is down to about 10 percent today. The trend for the future will probably be to buildsmall-scale hydro plants that can generate electricity for a single community.

[T]he construction of surface reservoirs has slowed considerably in recent years. In themiddle of the 20th Century, when urbanization was occurring at a rapid rate, many reser-voirs 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

Hydroelectric energy is produced by the force of falling water. The capacity to producethis 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 transformedinto mechanical energy when the water rushes down the sluice and strikes the rotaryblades of the turbine. The turbines rotation spins electromagnets which generate currentin stationary coils of wire. Finally, the current is put through a transformer where the volt-age is increased for long distance transmission over power lines.

Hydroelectric-power production in the United States and the world

[I]n the United States, most states make some use of hydroelectric power, although, asyou can expect, states with low topographical relief, such as Florida and Kansas, producevery little hydroelectric power. But some states, such as Idaho, Washington, and Oregonuse hydroelectricity as their main power source. In 1995, all of Idahos power came fromhydroelectric plants.

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China has developed large hydroelectric facilities in the last decade and now lead theworld in hydroelectricity usage. But, from north to south and from east to west, countriesall over the world make use of hydroelectricitythe main ingredients are a large river anda drop in elevation.

Adapted from: (no date). Hydroelectric Power Water Use. United States Geological Survey (USGS).

Available online at: http://ga.water.usgs.gov/edu/wuhy.html

Power house

Transformer

Generator

Turbine

Penst

ock

StreamOutlet

Dam

Dam

Silt

Storage

resevoir

Sluice gates

Power transmission cables

Hydroelectric Power Generation

Figure8.1 Illustration by Maury Aaseng

HydroelectricPowerplant. Hydroelectric dams generate electricity via the force

of falling water. Once a river is blocked by a dam to form a reservoir, the dams

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.
http://ga.water.usgs.gov/edu/wuhy.htmhttp://ga.water.usgs.gov/edu/wuhy.htm

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ByNationalRenewableEnergyLaboratory

GeothermalEnergy

Many technologies have been developed to take

advantage of geothermal energythe heat fromthe earth. This heat can be drawn from severalsources: hot water or steam reservoirs deep inthe earth that are accessed by drilling; geother-mal reservoirs located near the earths surface,mostly located in the western U.S., Alaska, andHawaii; and the shallow ground near the Earthssurface that maintains a relatively constant tem-perature of 508608F.

This variety of geothermal resources allows themto be used on both large and small scales. A util-ity can use the hot water and steam from reser-voirs to drive generators and produce electricityfor its customers. Other applications apply the heat produced from geothermal directly tovarious uses in buildings, roads, agriculture, and industrial plants. Still others use the heatdirectly 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 theEarths surface, can be used to provide heat directly. This is called the direct use of geo-thermal energy.

Geothermal direct use has a long history, going back to when people began using hotsprings 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 thisgeothermal resource.

In modern direct-use systems, a well is drilled into a geothermal reservoir to provide asteady stream of hot water. The water is brought up through the well, and a mechanicalsystempiping, a heat exchanger, and controlsdelivers the heat directly for its intendeduse. A disposal system then either injects the cooled water underground or disposes of iton the surface.

Geothermal hot water can be used for many applications that require heat. Its current usesinclude heating buildings (either individually or whole towns), raising plants in green-houses, drying crops, heating water at fish farms, and several industrial processes, suchas pasteurizing milk.

Geothermal electricity production

Geothermal power plants use steam produced from reservoirs of hot water found a fewmiles or more below the Earths surface to produce electricity. The steam rotates a turbinethat activates a generator, which produces electricity.

Paul Chesley/National Geographic Stock

Geothermal steam runs from its source, a

geothermal plant in Iceland, to an electric

power plant.

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There are three types of geothermal power plants: dry steam, flash steam, and binarycycle.

Dry steam

Dry steam power plants draw from underground resources of steam. The steam is pipeddirectly from underground wells to the power plant where it is directed into a turbine/generator unit. There are only two known underground resources of steam in the UnitedStates: The Geysers in northern California and Yellowstone National Park in Wyoming,where theres a well-known geyser called Old Faithful. Since Yellowstone is protectedfrom development, 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 reservoirs of waterwith temperatures greater than 3608F (1828C). This very hot water flows up through wellsin 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 separated from the water andused to power a turbine/generator. Any leftover water and condensed steam are injectedback into the reservoir, making this a sustainable resource.

Binary steam

Binary cycle power plants operate on water at lower temperatures of about 22583608F(10781828C). Binary cycle plants use the heat from the hot water to boil a working fluid,usually an organic compound with a low boiling point. The working fluid is vaporizedin a heat exchanger and used to turn a turbine. The water is then injected back into theground to be reheated. The water and the working fluid are kept separated during thewhole 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 toheat and cool buildings. The shallow ground, or the upper 10 feet of the Earth, maintainsa temperature between 508 and 608F (108168C). This temperature is warmer than the airabove it in the winter and cooler in the summer.

Geothermal heat pump systems consist of three parts: the ground heat exchanger, theheat pump unit, and the air delivery system (ductwork). The heat exchanger is a systemof 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 absorbor relinquish heat within the ground.

In the winter, the heat pump removes heat from the heat exchanger and pumps it into theindoor air delivery system. In the summer, the process is reversed, and the heat pumpmoves heat from the indoor air into the heat exchanger. The heat removed from the indoorair during the summer can also be used to heat water, providing a free source of hot water.

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CHAPTER 8Section 8.3 Nuclear Power

nuclearreactor: a

device that initiates and

maintains a controlled

nuclear fission chain

reaction to produce

electricity

nuclearfission: a

nuclear reaction in

which large atoms of

certain elements are

split into smaller atoms

with the release of a

large amount of energy

Geothermal heat pumps use much less energy than conventional heating systems, sincethey 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 Heat Pumps. National Renewable Energy Laboratory (NREL).

Available online at: http://www.nrel.gov/learning/re_geo_heat_pumps.html.

8.3Nuclear Power

The March 2011 earthquake and tsunami that triggered a catastrophe at Japans Fukushima nuclearcomplex has reignited debates over the role and safety of nuclear power. Because nuclear power cangenerate 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 nuclearsafety, the disposal of highly radioactive nuclear waste, and the high cost of nuclear constructionhave hindered the development of this energy source. In this section, Robinson OBrien-Bours ofthe Ashbrook Center and Amory Lovins of the Rocky Mountain Institute respond to the nuclearcrisis in Japan and offer differing viewpoints of the future for nuclear power.

Most nuclear reactors, including the ones damaged by the tsunami in Japan, are based on theconcept ofnuclear fission. In nuclear fission, the nuclei of a heavy element like uranium is bom-barded with neutrons causing it to split apart and release multiple neutrons along with heat andradiation. The neutrons released in this process can go on and bombard other uranium atoms andcreate 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 usedto boil water and produce steam to spin a turbine and generate electricity.

In the first part of this section, Robinson OBrien-Bours argues that theevents that triggered the nuclear catastrophe in Japan were so unprecedentedthat the situation there should not have any bearing on decisions to developnuclear power in the United States. He goes on to suggest that newer nuclearreactor designs are far safer than the design used at the plant in Japan. Inthe second part of this section, physicist Amory Lovins argues that the samesort of catastrophe could indeed occur in the U.S. and that nuclear poweris the only form of energy that leaves so little room for error. Beyond safetyconcerns, Lovins also points out that, even before the Japan nuclear disaster,demand for new nuclear power plants was in steep decline due to the highcosts associated with this form of energy. As such, its not public opposi-tion or safety fears that are preventing a nuclear resurgence in the U.S., justeconomics.
http://www.nrel.gov/learning/re_geo_heat_pumps.htmlhttp://www.nrel.gov/learning/re_geo_heat_pumps.html

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Chernobyl: an accident

that occurred onApril 26, 1986, at the

Chernobyl Nuclear

Power Plant in the

Ukrainian SSR resulting

in the release of large

quantities of radioactive

contamination into the

atmosphere

Indefenseofnuclearpower

ByRobinsonOBrien-Bours

What is going on with the Japanese

nuclear reactors is, without question,a terrible event that can possibly addmore hardship onto an already unspeakabletragedy. The explosions and the threat of a radia-tion leak are troubling, and Japanese engineersand scientists are doing everything humanlypossible to contain the situation. Yes, there is athreat of a nuclear meltdownbut there is alsoa chance that an asteroid will slam into the Earthon December 12, 2012, or that the next time youcross the street a semi will hit you. Opponents ofnuclear energy in the United States ought not to

politicize this horrible tragedy in their attemptsto stop the spread of the cleanest and most effi-cient, environmentally-friendly source of energythat we have.

The media is comparing the threat to Chernobyland some politicians are calling for a completemoratorium on the spread of nuclear energy.This is nothing more than sensationalist fear-mongering. The Chernobyl disaster was caused by the absurd inefficiencies of the Soviets andmassive flaws in the power plants design. The

primary problematic power plant in Japan hassafeguard after safeguard installed, including aspecial container around the reactor built specifically for this kind of disaster situation.Should the container be breached, the Japanese government already has things in place topour concrete over it as was done to contain Chernobyl.

It is worth noting that the facility itself was fairly agedforty years, I read in one arti-cleand that newer designs have even more safeguards and redundancies to prevent thistype of thing. It is also worth noting that this facility withstood one of the most power-

ful earthquakes in recorded history, and a subsequent tsunamiandyet, despite this, the disaster is unfolding very, very slowly, meaningthat the safeguards were mostly doing their job and that the Japaneseare doing a good job at attempting to avert this disaster. These typesof disasters do not happen frequently; seeking a nuclear moratoriumbecause of this event is no different than refusing to step on a planebecause they crash or get taken over occasionally.

Disasters happen, and we are usually well-prepared for them. Someare more severe than we can possibly imagine, and they test andendanger us. Rather than living in fear that such disasters will happenall the time, we should focus ononce this crisis is overlearning

iStockphoto/Thinkstock

Just as nuclear power appeared poised to

make a come-back as a source of zero-

carbon energy, the disaster at Japans

Fukashima Daiichi reactor reminded people

of the long-term risks even one accident

poses to communities.

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meltdown: the melting

of a nuclear reactor

vessel causing the

release of a substantial

amount of radiation

into the environment

light-waterreactor:

a common nuclear

reactor that uses water

as a moderator and

coolant

about what went wrong and what went right with these reactors in Japan, and working toaddress or implement whatever is discovered. We need to take this opportunity to makenuclear power better, more efficient, and more safe than it already is for these once-in-a-lifetime natural disasters. And this problem is just that: one caused by a severe naturaldisaster, not the incompetence of engineers or operators. As our country continues the

debate over nuclear power, we should keep that fact in mind; its a problem, yeah, but itis a rare oneand one that we are getting much better at preparing for and addressing.There are real fears and concerns over nuclear energy, and what Japan is facing right nowis a horrible situation on top of a heartbreaking tragedy that I hope they can overcome,but we should take the opportunity to learn how to make this clean and efficient powerbetter and safer for our usenot retreat into sensationalism and ban even the thought ofpursuing nuclear energy.

Adapted from OBrien-Bours, R. 2011. In Defense of Nuclear Power. Environment. Copyright Taylor & Francis,

Ltd. Available online at: http://nlt.ashbrook.org/2011/03/defending-nuclear-power-in-tsunamis-wake.php .

LearningfromJapansnucleardisaster

ByArmoryB.Lovins

As heroic workers and soldiers strive to save stricken Japan from a new horrorradioactive falloutsome truths known for 40 years bear repeating.

An earthquake-and-tsunami zone crowded with 127 millionpeople is an unwise place for 54 reactors. The 1960s design of fiveFukushima-I reactors has the smallest safety margin and probablycant contain 90 percent of meltdowns. The U.S. has six identical and17 very similar plants.

Every currently operating light-water reactor, if deprived of powerand cooling water, can melt down. Fukushima had eight-hour batteryreserves, but fuel has melted in three reactors. Most U.S. reactors getin trouble after four hours. Some have had shorter blackouts. Muchlonger ones could happen.

Overheated fuel risks hydrogen or steam explosions that damageequipment and contaminate the whole siteso clustering many reac-tors together (to save money) can make failure at one reactor cascadeto the rest.

Nuclear power is uniquely unforgiving: as Swedish Nobel physicist Hannes Alfvn said,No acts of God can be permitted. Fallible people have created its half-century history ofa few calamities, a steady stream of worrying incidents, and many near-misses. Americahas been lucky so far. Had Three Mile Islands containment dome not been built double-strength because it was under an airport landing path, it may not have withstood the 1979accidents hydrogen explosion. In 2002, Ohios Davis-Besse reactor was luckily caught justbefore its massive pressure-vessel lid rusted through.
http://nlt.ashbrook.org/2011/03/defending-nuclear-power-in-tsunamis-wake.phphttp://nlt.ashbrook.org/2011/03/defending-nuclear-power-in-tsunamis-wake.php

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Regulators havent resolved these or other keysafety issues, such as terrorist threats to reactors,lest they disrupt a powerful industry. U.S. regu-lation is not clearly better than Japanese regu-lation, nor more transparent: industry-friendly

rules bar the American public from meaningfulparticipation. Many presidents nuclear booster-ism [the practice of actively promoting] also dis-courages inquiry and dissent.

Nuclear-promoting regulators inspire even lessconfidence. The International Atomic EnergyAgencys 2005 estimate of about 4,000 Cher-nobyl deaths contrasts with a rigorous 2009review of 5,000 mainly Slavic-language scientificpapers the IAEA overlooked. It found deathsapproaching a million through 2004, nearly

170,000 of them in North America. The total tollnow exceeds a million, plus a half-trillion dol-lars economic damage. The fallout reached fourcontinents, just as the jet stream could swiftlycarry Fukushima fallout.

Fukushima I-4s spent fuel alone, while in thereactor, had produced (over years, not in aninstant) more than a hundred times more fis-sion energy and hence radioactivity than both

1945 atomic bombs. If that already-damaged fuel keeps overheating, it may melt or burn,releasing into the air things like cesium-137 and strontium-90, which take several centu-ries to decay a millionfold. Unit 3s fuel is spiked with plutonium, which takes 482,000years.

The cost of nuclear power

Nuclear power is the only energy source where mishap or malice can kill so many peopleso far away; the only one whose ingredients can help make and hide nuclear bombs; theonly climate solution that substitutes proliferation, accident, and high-level radioactivewaste dangers. Indeed, nuclear plants are so slow and costly to build that they reduce andretard climate protection.

Heres how. Each dollar spent on a new reactor buys about two to ten times less carbonsavings and is 20 to 40 times slower, than spending that dollar on the cheaper, faster,safer solutions that make nuclear power unnecessary and uneconomic: efficient use ofelectricity, making heat and power together in factories or buildings (cogeneration),and renewable energy. The last two made 18 percent of the worlds 2009 electricity (whilenuclear made 13 percent, reversing their 2000 shares)and made over 90 percent of the2007 to 2008 increase in global electricity production.

Jack Fletcher/National Geographic Stock

A man carefully places the fuel element into

a shipboard nuclear reactor.

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Those smarter choices are sweeping the global energy market. Half the worlds newgenerating capacity in 2008 and 2009 was renewable. In 2010, renewables, excluding bighydro dams, won $151 billion of private investment and added over 50 billion watts (70percent the total capacity of all 23 Fukushima-style U.S. reactors) while nuclear got zeroprivate investment and kept losing capacity. Supposedly unreliable windpower made 43

percent to 52 percent of four German states total 2010 electricity. Non-nuclear Denmark,21 percent windpowered, plans to get entirely off fossil fuels. Hawaii plans 70 percentrenewables by 2025.

In contrast, of the 66 nuclear units worldwide officially listed as under construction atthe end of 2010, 12 had been so listed for over 20 years, 45 had no official startup date, halfwere late, all 66 were in centrally planned power systems50 of those in just four (China,India, Russia, South Korea)and zero were free-market purchases. Since 2007, nucleargrowth has added less annual output than just the costliest renewablesolar powerandwill probably never catch up. While inherently safe renewable competitors are wallopingboth nuclear and coal plants in the marketplace and keep getting dramatically cheaper,nuclear costs keep soaring, and with greater safety precautions would go even higher.

Tokyo Electric Co., just recovering from $1020 billion in 2007 earthquake costs at its otherbig nuclear complex, now faces an even more ruinous Fukushima bill.

Since 2005, new U.S. reactors (if any) have been 100 percent-plus subsidizedyet theycouldnt raise a cent of private capital, because they have no business case. They cost 23times as much as new windpower, and by the time you could build a reactor, it couldnteven beat solar power. Competitive renewables, cogeneration, and efficient use candisplace all U.S. coal power more than 23 times overleaving ample room to replacenuclear powers half-as-big-as-coal contribution toobut we need to do it just once. Yetthe nuclear industry demands ever more lavish subsidies, and its lobbyists hold all otherenergy efforts hostage for tens of billions in added ransom, with no limit.

Moving forward

Japan, for its size, is even richer than America in benign, ample, but long-neglected energychoices. Perhaps this tragedy will call Japan to global leadership into a post-nuclear world.And before America suffers its own Fukushima, it too should ask, not whether unfinance-ably costly new reactors are safe, but why build any more, and why keep running unsafeones. China has suspended reactor approvals. Germany just shut down the oldest 41 per-cent of its nuclear capacity for study. Americas nuclear lobby says it cant happen here, sopile on lavish new subsidies.

A durable myth claims Three Mile Island halted U.S. nuclear orders. Actually they stopped

over a year beforedead of an incurable attack of market forces. No doubt when nuclearpowers collapse in the global marketplace, already years old, is finally acknowledged, itwill be blamed on Fukushima. While we pray for the best in Japan today, let us hope itspeoples sacrifice will help speed the world to a safer, more competitive energy future.

Adapted from Lovins, A. B. 2011. Learning from Japans Nuclear Disaster. Published by Rocky Mountain Institute

www.rmi.org. Available online at: http://blog.rmi.org/LearningFromJapansNuclearDisaster .
http://www.rmi.org/http://blog.rmi.org/LearningFromJapansNuclearDisasterhttp://blog.rmi.org/LearningFromJapansNuclearDisasterhttp://www.rmi.org/

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CHAPTER 8Section 8.4 Energy Efciency

8.4Energy Efficiency

Although much attention is focused on the potential for renewable energy sources such as solar andwind, relatively little consideration is given to the idea of energy efficiency. Energy efficiency canbe 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 effi-ciency means reducing the need to produce energy in the first placeregardless of where thatenergy actually comes from. In the following reading, Eberhard K. Jochem of the Swiss FederalInstitute of Technology provides examples of energy efficiency in action and suggests ways to boostthe efficiency of energy use in the future.

Just as section 5.4 discussed reducing water demand as a means of addressing potential watershortages, 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 bringmultiple benefits. Improved vehicle efficiency could reduce oil demand and decrease our dependenceon foreign oil sources. More efficient use of electricity in homes and businesses could reduce theneed to burn as much coal in power plants and reduce both local/regional air pollution as well as

greenhouse gas emissions.

However, there are economic and political barriers to more widespread adoption of energy efficiencymeasures. Because energy efficiency typically involves an upfront cost with payback over timeforexample, adding insulation to a home or installing new, energy-efficient windowsmany hom-eowners and businesses hesitate or are unable to make such investments. Politically, energy effi-ciency does not seem as exciting as new energy sources like wind and solar, nor does it have a politi-cal lobby behind it the way fossil fuels do. These and other barriers can be overcome through policiessuch as tax incentives for energy efficient investments and better labeling of efficient appliances.

ByEberhardK.Jochem

The huge potential of energy efficiency measures for mitigating the release of green-house gases into the atmosphere attracts little attention when placed alongside themore glamorous alternatives of nuclear, hydrogen or renewable energies. But devel-

oping a comprehensive efficiency strategy is the fastest and cheapest thing we can doto reduce carbon emissions. It can also be profitable and astonishingly effective, as tworecent examples demonstrate.

From 2001 through 2005, Procter & Gambles factory in Germany increased production by45 percent, but the energy needed to run machines and to heat, cool and ventilate buildingsrose by only 12 percent, and carbon emissions remained at the 2001 level. The major pil-lars supporting this success include highly efficient illumination, compressed-air systems,

new designs for heating and air conditioning, funneling heat losses from compressors intoheating buildings, and detailed energy measurement and billing. In some 4,000 housesand buildings in Germany, Switzerland, Austria and Scandinavia, extensive insulation,highly efficient windows and energy-conscious design have led to enormous efficiencyincreases, enabling energy budgets for heating that are a sixth of the requirement for typi-cal buildings in these countries. Improved efficiencies can be realized all along the energychain, from the conversion of primary energy (oil, for example) to energy carriers (suchas electricity) and finally to useful energy (the heat in your toaster). The annual globalprimary 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.

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After conversion these primary energy sourcesdeliver roughly 300,000 petajoules of so-calledfinal energy to customers in the form of electric-ity, gasoline, heating oil, jet fuel, and so on.

The next step, the conversion of electricity, gas-oline, and the like to useful energy in engines, boilers and lightbulbs, causes further energylosses of 154,000 petajoules. Thus, at presentalmost 300,000 petajoules, or two thirds of theprimary energy, are lost during the two stagesof energy conversion. Furthermore, all usefulenergy is eventually dissipated as heat at vari-ous temperatures. Insulating buildings moreeffectively, changing industrial processes anddriving lighter, more aerodynamic cars wouldreduce the demand for useful energy, thus sub-

stantially reducing energy wastage.

Given the challenges presented by climate change and the high increases expected inenergy prices, the losses that occur all along the energy chain can also be viewed as oppor-tunitiesand efficiency is one of the most important. New technologies and know-howmust replace the present intensive use of energy and materials.

Roomforimprovement

Because conservation measures, whether incorporated into next years car design or anew 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 forsaving energy. In countries belonging to the Organization for Economic Cooperation andDevelopment (OECD) and in the megacities of emerging countries, buildings contributemore 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 crisisin the 1970s, air conditioners in the U.S. were redesigned to use less power with little lossin cooling capacity and new U.S. building codes required more insulation and double-paned windows. 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 differencein consumption between 1974 efficiency levels and 2001 levels is equivalent to avoidingthe generation of 40 gigawatts at power plants.) Changing to compactfluorescent lightbulbs yields an instant reduction in power demand;these bulbs provide as much light as regular incandescent bulbs, last10 times longer and use just one fourth to one fifth the energy.

Despite these gains, the biggest steps remain to be taken. Many build-ings were designed with the intention of minimizing constructioncosts rather than life-cycle cost, including energy use, or simply inignorance of energy-saving considerations. Take roof overhangs, for

life-cyclecost: the sum

of all recurring and one-

time (non-recurring)

costs over the full life

span of a good, service,

structure, or system

Blend Images/photolibrary

Citizens and businesses alike are finding

that energy efficiency, such as use of energy

efficient appliances, offers significant

financial savings, while also reducing

pollution.

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example, which in warm climates traditionally measured a meter or so and which arerarely used today because of the added cost, although they would control heat buildup onwalls and windows. One of the largest European manufacturers of prefabricated housesis now offering zero-net-energy houses: these well-insulated and intelligently designedstructures 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 buildingcodes. Because buildings have a 50- to 100-year lifetime, efficiency retrofits are essential.But we need to coordinate changes in existing buildings thoughtfully to avoid replacinga single component, such as a furnace, while leaving in place leaky ducts and single-panewindows that waste much of the heat the new furnace produces. One example highlightswhat might be done in industry: although some carpet manufacturers still dye their prod-ucts at 100 to 140 degrees Celsius, others dye at room temperature using enzyme technol-ogy, reducing the energy demand by more than 90 percent.

Theimportanceofpolicy

To realize the full benefits of efficiency, strong energy policies are essential. Among theunderlying reasons for the crucial role of policy are the dearth of knowledge by manufac-turers and the public about efficiency options, budgeting methods that do not take properaccount of the ongoing benefits of long-lasting investments, and market imperfectionssuch as external costs for carbon emissions and other costs of energy use. Energy policy setby governments has traditionally underestimated the benefits of efficiency. Of course, fac-

tors other than policy can drive changes in effi-ciencyhigher energy prices, new technologiesor cost competition, for instance. But policieswhich include energy taxes, financial incentives,professional training, labeling, environmentallegislation, greenhouse gas emissions trading

and international coordination of regulations fortraded productscan make an enormous differ-ence. Furthermore, rapid growth in demand forenergy services in emerging countries providesan opportunity to implement energy-efficientpolicies from the outset as infrastructure grows:programs to realize efficient solutions in build-ings, transport systems and industry would givepeople the energy services they need withouthaving to build as many power plants, refineriesor gas pipelines.

Japan and the countries of the European Unionhave been more eager to reduce oil imports thanthe U.S. has and have encouraged productivitygains through energy taxes and other measures.But all OECD countries except Japan have so farfailed to update appliance standards. Nor dogas and electric bills in OECD countries indi-cate how much energy is used for heating, say,as opposed to boiling water or which uses are

Mike Kemp/Rubberball/photolibrary

Replacing incandescent light bulbs with

energy-efficient alternatives is one way to

reduce energy consumption at work and

home.

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CHAPTER 8Section 8.5 Case HistoryA Zero Energy Ofce Building

the most energy-intensivethat is, where a reduction in usage would produce the great-est energy savings. In industry, compressed air, heat, cooling and electricity are often notbilled 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 dwell-ings were equipped to adhere to low-energy standards (about 30 kilowatt-hours persquare meter per year), reducing the annual energy demand for heating those buildingsby a factor of six. Before the retrofit, the dwellings were difficult to rent; now demand isthree 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-WattSocietyan annual primary energy use of 2,000 watts (or 65 gigajoules) per capita. Realiz-ing this vision in industrial countries would reduce the per capita energy use and relatedcarbon emissions by two thirds, despite a two-thirds increase in GDP, within the next 60 to80 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 feasiblefor industrial countries in the second half of this century.

To some people, the term energy efficiency implies reduced comfort. But the concept ofefficiency means that you get the same servicea comfortable room or convenient travelfrom home to workusing less energy. The EU, its member states and Japan have begunto tap the substantialand profitablepotential of efficiency measures. To avoid the ris-ing costs of energy supplies and the even costlier adaptations to climate change, efficiencymust become a global activity.

Adapted from Jochem, E. K. 2006. An Efficient Solution. Scientific American, September: 6467. Reproduced with

permission. Copyright 2006 Scientific American, Inc. All rights reserved.

8.5Case HistoryA Zero Energy Office Building

Commercial buildings are a significant consumer of energy in our society and a major source ofcarbon dioxide emissions. In this article, Kirk Johnson ofThe New York Times profiles a fas-cinating experiment in constructing a net zero energy commercial office building. A net zerobuilding is designed to produce as much energy as it uses over the course of a day, week, month, oryear. The National Renewable Energy Lab (NREL) building in Golden, Colorado, is designed to dojust that. The building is first and foremost designed to be ultra-energy efficient. Because even themost 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 thatit has been done using existing technologies and at a cost that is comparable to traditional buildingdesigns.

Many homes, offices, and other buildings built in the United States suffer from what is some-times called a principal-agent problem. The principal-agent problem is when one person or businessmakes decisions that will have a large impact on energy consumption while another person or busi-ness actually pays the energy bills. Many home and office builders cut corners on energy efficient

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principal-agent

problem: situation that

occurs when someone

makes a decision

that impacts energy

consumption and the

cost is passed on to

another person or

business

net-zeroenergy: a

building or installation

that produces as much

energy as it consumes,

considered to be energy

self-sufficient or near

self-sufficient

features during construction in order to keep costs down. Likewise, they areunlikely 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-agentproblem is the landlord who refuses to improve the efficiency of an apart-ment in cases where the tenant has to pay the energy bills.

There was no principal-agent problem in the design and construction ofthe NREL building in Colorado. From start to finish energy efficiency andrenewable 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 enhancedwhen renewable technologies are paired with energy efficiency. If a home or office building is energyinefficient it would require an enormous investment in solar panels or other renewable energydevices to meet energy demand. However, if energy demand can first be brought down by 30, 50, or70% 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 occupantsof a building are provided with real-time information on how their behaviors influence energyconsumption, they will often modify those behaviors in ways that can save significant amounts ofenergy over time.

ByKirkJohnson

The west-facing windows by Jim Duffields desk started automatically tinting blueat 2:50 p.m. on a recent Friday as the midwinter sun settled low over the RockyMountain foothills.

Around his plant-strewn work cubicle, low whirring air sounds emanated from speak-ers in the floor, meant to mimic the whoosh of conventional heating and air-conditioningsystems, neither of which his 222,000-square-foot office building has, or needs, even hereat 5,300 feet elevation. The generic white noise of pretend ductwork is purely for back-ground and workplace psychologymanagers found that workers needed somethingmore than silence.

Meanwhile, the photovoltaic roof array was beating a retreat in the fading, low-angledlight. It had until 1:35 p.m. been producing more electricity than the building could useathree-hour energy budget surplusinterrupted only around noon by a passing cloudformation.

For Mr. Duffield, 62, it was just another day in what was designed, inpainstaking detail, to be the largest net-zero energy office buildingin the nation. Hes still adjusting, six months after he and 800 engi-neers and managers and support staff from the National RenewableEnergy Lab moved in to the $64 million building, which the federalagency has offered up as a template for how to do affordable, super-energy-efficient construction.

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Its sort of a wonderland, said Mr. Duffield, an administrative support worker, as thewindow shading system reached maximum.

Most office buildings are divorced, in a way, from their surroundings. Each day in themechanical 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 labs Research Support Facility building is more like a mirror, or perhaps asponge, to its surroundings. From the light-bending window louvers [a window coveringwith adjustable slats] that cast rays up into the interior office spaces, to the giant concretemaze in the sub-basement for holding and storing radiant heat, every day is completelydifferent.

Collectingdata

This is the story of one randomly selected day in the still-new buildings life: Jan. 28, 2011.

It was mostly sunny, above-average temperatures peaking in the mid-60s, light windsfrom 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 inand out, seeking, always, the balance of zero net use over 24 hoursa goal that managerssay probably wont be attainable until early next year [2012], when the third wing of theproject and a parking complex are completed.

With daylight, the buildings pulse quickened. The photovoltaic panels kicked in withelectricity at 7:20 a.m.

As employees began arriving, electricity usefrom cellphone chargers to elevatorsbegan to increase. Total demand, including the 65-watt maximum budget per workspacefor all uses, lighting to computing, peaked at 9:40 a.m.

Meanwhile, the basement data center, which handles processing needs for the 300-acrecampus, was in full swing, peaking in electricity use at 10:10 a.m., as e-mail and researchspreadsheets began firing through the circuitry.

For Mr. Duffield and his co-workers, that was a good-news bad-news moment: The datacenter is by far the biggest energy user in the complex, but also one of its biggest produc-ers of heat, which is captured and used to warm the rest of the building. If there is a secretclubhouse for the worlds energy and efficiency geeks, it probably looks and feels justabout like this.

Nothing in this building was built the way it usually is, said Jerry Blocher, a senior proj-ect 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, theunpicked fruit of energy conservation. Commercial buildings use about 18 percent of the

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nations total energy each year, and many of those buildings, especially in years past, weredesigned 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 multi-

tude of traditional design sins, but rather a rethinking of everything, down to the smallestelements, all aligned in a watt-by-watt march toward a new kind of building.

Alivinglaboratory

Managers even pride themselves on the fact that hardly anything in their building, at leastin its individual component pieces, is really new.

Off-the-shelf technology, cost-efficient as well as energy-efficient, was the mantra to find-ing what designers repeatedly call the sweet spotzero energy that doesnt break a sweat,or the bank. More than 400 tour groups, from government agency planners to corpora-

tions to architects, have trouped through since the first employees moved in last summer.

Its all doable technology, said Jeffrey M. Baker, the director of laboratory operations atthe Department of Energys Golden field office. Its a living laboratory.

Some of those techniques and tricks are as old as the great cathedrals of Europe (massholds 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 thatfling 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 nudgingthe 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 lightand ventilation), which raised privacy concerns among workers. Even the managersoffices have no ceilingsagain to allow the flow of natural light, as cast from the ceiling.

The open office is different, said Andrew Parker, an engineer. You want to be next tosomeone quiet.

Designinggreenbehavior

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 structuralcolumns that hold the building up? They came from 3,000 feet of natural gas pipebuiltfor the old energy economy and never used. The wood trim in the lobby? Lodgepole pinetrees310 of themkilled by a bark beetle that has infested millions of acres of forest inthe West.

Ultimately, construction costs were brought in at only $259 a square foot, nearly $77 belowthe average cost of a new super-efficient commercial office building, according to figuresfrom Haselden Construction, the builder. Other components of the design are based onobservation of human nature.

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People print less paper when they share a central printer that requires a walk to the copyroom. People also use less energy, managers say, when they know how much theyreusing. A monitor in the lobby offers real-time feedback on eight different measures.

The feedback comes right down to a workers computer screen, where a little icon pops

up when the buildings central computer says conditions are optimal to crank the hand-opened windows. (Other windows, harder to reach, open by computer command.)

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 oflights.

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 coffeemaker or something starts showing up.

Lessonslearned

If Anthony Castellano is a measure, the training regimen has clearly taken root. Mr. Cas-tellano, who joined the research laboratory last year as a Web designer after years in pri-vate industry, said the immersion in energy consciousness goes home with him at night.

My kids are yelling at me because Im turning off all the lights, Mr. Castellano said.

At 5:05 p.m., the solar cells stopped producing. Declining daylight in turn produced abrief spike in lighting use, at 5:55 p.m. Five minutes later, the building management sys-

tem began shutting off lights in a rolling two-hour cycle (the computer gives a few friendlyblinks, 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 hasbrought, said his desk has become a regular stop on the group tours. If the building is aliving 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 onthem as a measure of building health.

They refer to this as the buildings carbon sink, he said.

And Mr. Duffields babiesamaryllis, African violet, a pink trumpet vineare veryhappy 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 ithas continued to grow, and when the days start getting longer it might even bloom.

Adapted from Johnson, K. 2011. Soaking Up the Sun to Squeeze Bills to Zero. New York Times. Available online at:

http://www.nytimes.com/2011/02/15/science/15building.html .
http://www.nytimes.com/2011/02/15/science/15building.htmlhttp://www.nytimes.com/2011/02/15/science/15building.html

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CHAPTER 8Chapter Summary

Chapter Summary

F

ossil fuels like oil, coal, and natural gas currently meet 80% of our energy requirements.However, concerns about the political, economic, and environmental impacts haveincreased interest in finding alternative energy sources. One possible approach would be

to expand the use of nuclear power since this energy source is essentially carbon-free and there-fore does not contribute to global climate change. However, nuclear power comes with its ownissues of safety, cost, waste storage, and the dangers of nuclear material getting into the handsof terrorists. It has been suggested that we are now in the early stages of an energy revolutionor transition away from non-renewable fossil fuels, and that we are moving toward using morerenewable forms of energy like solar and wind. Earlier energy transitions included the shiftfrom wood and other forms of biomass to coal in the 19th century, as well as the rapid rise inthe use of oil over the second half of the 20th century. Any significant shift from non-renewableto 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.

A key difference between non-renewable and renewable energy sources can be illustrated

through concepts of stocks and flows. Non-renewable energy sources such as oil and coal cur-rently exist in fixed amounts or stocks. We cannot hope for any increase in these stocks. The high-energy content and versatility in use of these fossil fuel stocks makes them especially attractiveas a form of energy. In contrast, renewable energy sources like wind and sunlight are availablenot as fixed stocks of energy but as flows. These flows are renewable in that the sun will keepon shining and the wind will keep blowing no matter how much we make use of them. In addi-tion, these flows are massivethe total energy contained in one hour of sunlight shining on theEarth is more than all of the commercial energy consumed on the planet in one year; and theenergy contained in wind represents more than 15 times the global energy demand.

However, unlike the highly energy-dense fossil fuels these renewable energy flows are diffuseand intermittent. We have to deploy and develop extensive areas of solar panels and windturbines to capture enough energy to meet demand, and we have to account for the fact thatin a given location, on a particular day, the sun may not shine or the wind may not be strongenough to generate power. In this way we can categorize non-renewable energy sources asstock-limited and renewable energy sources as flow-limited.

In order to more effectively make use of renewable energy technologies and electricity fromnuclear power plants, we must pair their adoption with improvements in the efficiency ofenergy 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 ornuclear power plants that need to be put in place to meet remaining energy demand. This con-cept of synergy between renewable energy and energy efficiency is best illustrated in so-called

zero energy homes or buildings. Such structures produce as much energy as they consume overthe course of a day, week, or month, and represent the feasibility of utilizing renewable energysources to meet much of our energy needs.

In the next chapter the focus shifts away from issues of energy and climate change to con-cerns over pollution and waste management. In addition to reducing greenhouse gas emis-sions, renewable energy sources and nuclear power also have the potential to reduce local andregional air pollution problems. Moreover, efforts to reduce solid waste generation, such asthrough recycling, turn out to have significant benefits in terms of reducing energy use.

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CHAPTER 8Chapter Summary

KeyTerms

Critical Thinking and Discussion Questions

1. Solar photovoltaics are only one kind of renewable energy technology.What are the ideas behind the technologies to replace fossil fuel energyuse? Discuss their benefits and current obstacles to widespread use.

2. Corn-based ethanol is a biofuel, but what current agriculture practicesmake the production of this renewable energy source unsustainable (alsorefer to Chapter 3 for further discussion)?

3. What role does the government have in making renewable energy sourcesaccessible options for everyday consumers? What would help these con-sumers better understand the social costs of non-renewable sources?

4. All energy sources have drawbacks; even the clean hydropower option hasnegative ramifications. Weigh those against the possible consequences ofdeveloping nuclear power, a controversial alternative to fossil fuels. Dis-cuss recent events in Japan as well as the 20th century Chernobyl nuclearmeltdown in drawing conclusions about risk versus reward of nuclear

energy use.5. Based on the net-zero energy office building study, are energy efficiency andconservation efforts viable practices? Where do you think resistance to suchefforts comes from? Why arent these practices more common?

biofuels gas or liquid fuel made from plant

material

Chernobyl an accident that occurred on April26, 1986, at the Chernobyl Nuclear Power Plant

in the Ukrainian SSR, resulng in the release of

large quanes of radioacve contaminaon

into the atmosphere

Fischer-Tro

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