Energy - Environmental Science - page 312

cogenerating microturbines, and a high-efficiency
(85-98%) natural gas furnace. The most wasteful and
expensive way is to use electric resistance heating
with the electricity produced by a coal-fired or nuclear
power plant.
■ Heat water more efficiently. One approach is to use a
tankless instant water heater (about the size of a small
suitcase) fired by natural gas or LPG but not by elec-
tricity. These devices, which are widely used in many
parts of Europe, heat water instantly as it flows
through a small burner chamber, provide hot water
only when it is needed, and use less energy than tradi-
tional water heaters.* A well-insulated, conventional
natural gas or LPG water heater is fairly efficient.
Nevertheless, all conventional natural gas and electric
resistance heaters waste energy by keeping a large
tank of water hot all day and night and can run out af-
ter a long shower or two.
■ Use energy-efficient appliances and lighting. If all
households in the United States used the most effi-
cient frost-free refrigerator now available, 18 large
(1,000-megawatt) power plants could close. Mi-
crowave ovens can cut electricity use for cooking by
25-50% (but not if used for defrosting food). Clothes
dryers with moisture sensors cut energy use by 15%,
and front-loading washers use 50% less energy than
top-loading models but cost about the same. Replac-
ing 21 energy-wasting incandescent light bulbs in a
house or building with energy-efficient fluorescent
bulbs typically saves $1,125. What a great investment
payoff.
■ Set strict energy-efficiency standards for new buildings.
Building codes could require that new houses use
60-80% less energy than conventional houses of the
same size, as has been done in Davis, California. Be-
cause of tough energy-efficiency standards, the aver-
age Swedish home consumes about one-third as much
energy as the average American home of the same size.

likely to waste it and not make investments in improv-
ing energy efficiency.
Another reason is a lack of tax breaks and other
economic incentives for consumers and businesses to
invest in improving energy efficiency compared to
government subsidies and tax breaks for energy alter-
natives such as fossil fuels and nuclear power..
Would you like to earn about 20% per year on
your money, tax free and risk free? Invest it in improv-
ing the energy efficiency of your home and in energy-
efficient lights and appliances. You will get your in-
vestment back in a few years and then make about 20%
per year by having lower heating, cooling, and electric-
ity bills. This is a win-win deal for you and the earth.

x

H OW W OULD Y OU V OTE ? Should the United States or
the country where you live greatly increase its emphasis
on improving energy efficiency? Cast your vote online at
http://biology.brookscole.com/miller11.

13-5 USING RENEWABLE ENERGY
TO PROVIDE HEAT AND ELECTRICITY

Science and Economics: Types
of Renewable Energy
Six types of renewable energy are solar, flowing water,
wind, biomass, hydrogen, and geothermal.
One of the four keys to sustainability (Figure 6-18,
p. 126), based on learning from nature, is to rely mostly
on renewable solar energy. We can get renewable solar
energy directly from the sun or indirectly from moving
water, wind, and biomass. Two other forms of renew-
able energy are geothermal energy from the earth's in-
terior and use of renewable energy to produce hydro-
gen fuel from water. Like fossil fuels and nuclear
power, each of these alternatives has advantages and
disadvantages.
If renewable energy is so great, why is it that it
provides only 18% of the world's energy and 6% of the
United States' energy? One reason is that renewable
energy resources have received and continue to re-
ceive much lower government tax breaks, subsidies,
and research and development funding than fossil fu-
els and nuclear power have received for decades. The
other reason is that the prices we pay for fossil fuels
and nuclear power do not include the costs of their
harm to the environment and to human health.
In other words, the economic dice have been
loaded against solar, wind, and other forms of renew-
able energy. If the economic playing field was made
more even, energy analysts say that many of these
forms of renewable energy would take over—another
example of the you-get-what-you-reward economic prin-
ciple in action.

Economics: Why Are We Still Wasting
So Much Energy?
Low-priced fossil fuels and lack of government
tax breaks for saving energy promote energy
waste.
With an impressive array of benefits (Figure 13-22),
why is so little emphasis placed on improving energy
efficiency? One reason is a glut of low-cost gasoline
(Figure 13-23) and other fossil fuels. As long as energy
remains artificially cheap because its market price
does not include its harmful costs, people are more

*They work great. I used them in a passive solar office and living
space for 15 years. For information on available models visit
www.foreverhotwater.com .