Solar energy: Power for the future 117woven into fabric for carrying cases, backpacks, and bags that can recharge electrical equip-
ment, cell phones, and MP3 players.
◆ Energy paybackNaysayers claim that solar energy is prohibitively expensive. At 20 cents
per kilowatt hour, energy produced by PV plants costs ten times more than energy generated
by fossil fuel–burning plants. Calculating the “payback,” or time required to ofset the carbon
emissions from manufacturing, depends on many variables. he average payback of a resi-
dential or commercial PV system is estimated at four years, and technological advances are
expected to reduce that timeframe. Because of additional construction and infrastructure
costs, PV solar farms have a payback of 20 years or more. When focusing on costs, one must
also consider that the scarcer fossil fuels become, the more expensive they will become.
◆ Long-term energy savings Not all individuals or businesses can aford a solar system. A
two-kilowatt of-grid private system can cost $20,800, and a ten-kilowatt system can cost up to
$104,000. A zero-energy home that feeds surplus power into a grid during the summer and
draws electricity back on cloudy days or in winter adds an extra 10 to 20 percent to building
costs, but over a period of 20 to 30 years, these additional expenses are recovered in energy
savings. By reducing overall energy consumption and incorporating further energy-saving fea-
tures into homes and buildings, a return on investment can be realized much sooner. Buildings
that take advantage of passive solar heating can cut their heating costs in half. hrough net
metering, individuals can sell surplus electricity back to utility companies, as is done in Ger-
many, Italy, and Spain.
11 Despite the safety, eiciency, and numerous environmentally friendly applications of solar
energy, commitment to its development has luctuated with the price of oil, particularly in North
America, where government energy policy is strongly inluenced by oil companies. During the
1973–74 OPEC oil embargo and the ensuing energy crisis, President Carter had solar panels
installed on the White House, and the U.S. Department of Energy initiated the Federal Photo-
voltaic Utilization Program to install and test PV systems, many of which are still in operation.
When the embargo was lited six months later, oil prices stabilized and solar energy as a national
energy policy ended up on the back burner.
12 In the meantime, solar energy has fared better in energy-conscious Europe and Japan, where
the solar industry is promoted through government subsidies and tax incentives. Since 1990,
Germany has become a world leader in thermal solar technology and the foremost installer of
photovoltaic systems, having spent billions so far to promote solar energy. In Spain, all new build-
ings are required to include solar power, and Japanese researchers have developed a solar cell that
can store electricity as well as generate it. Solar power is the cheapest, most practical solution for
developing nations and remote areas without access to a national power grid, such as Antarctica
and rural areas in China.
13 he onset of global warming and warnings from reputable organizations such as the United
Nations’ Intergovernmental Panel on Climate Change, have revived the solar market in North
America and spurred government support of solar technology. In the United States, consumer
demand and government tax credits are giving sales of solar systems a boost. In the irst quarter
of 2012, solar panel installations increased 85 percent over the previous year’s irst quarter, and
total installations are expected to reach 3,300 megawatts, making the United States the fourth
largest solar market.
14 If the upward trend continues and the global solar industry grows to a predicted $51 billion
by 2014, it could very well be said that the world is beginning to see the light.After reading
In the Pre-reading section, check to see if your predictions about the reading text were correct.