© Kyoungil Jeon/Getty; inset, © Fabio Bianchini/iStockphoto
0
0.2
0.4
0.6
0.8
1
1.2
1980
Cost per kilowatt-hour (dollars)
1985 1990 1995
Year
2000 2005 2010
Based on data from M. A. Schilling, M. Esmundo,
Energy
Policy
37 (2009) 1767–1781; U.S. DOE Energy Information
Agency, (2012).
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These thin-film solar cells look much like conventional roofing
materials.
'ENERATING COSTS OF ELECTRIC POWER PLANTS s Table 18.1
Generating costs (cents
Energy source per kilowatt-hour)*
Hydropower 2–10
Biomass 6–9
Geothermal 3–8
Wind 4–7
Solar thermal 5–13
Photovoltaics 15–25
Natural gas 5–7
Coal 6–8
Nuclear power 6–8
*Electricity production and consumption are measured in
kilowatt-hours (kWh). As an example, one 50-watt light bulb
that is on for 20 hours uses 1 kWh of electricity (50 × 20 = 1000
watt-hours = 1 kWh).
Cost of electricity from solar photovoltaic
ViÃ]Ê£näqÓä£äÊUÊ}ÕÀiÊ£n°ÎÊ
The cost of generating electricity using photovoltaic cells has
dropped from over one dollar per kilowatt-hour three decades
ago to about $0.15 in 2010.
The average cost of electricity
to consumers in the United States is currently
about 12 cents per kilowatt-hour. Based on this
graph, in what year do you expect power from
photovoltaics to cost less than the average cost?
Think Critically
manufacture than standard PVs, has decreased costs for
PVs across the board. Japan is considering a national policy
that all new buildings incorporate PV on rooftops by 2030.
Through the Million Solar Roofs initiative, California ex-
pects to have solar roofing on 1 million buildings by 2016.
By late 2012, Californians had installed over 1000 MW
of solar capacity on their roofs. This is equivalent to the
power generated by a typical nuclear power plant. An-
other technological advance that shows promise is dye-
sensitized solar cells, which can be produced at about
one-fifth the cost of conventional silicon panels.
While operating PVs creates no air or water pollution,
the manufacturing process requires industrial chemicals,
many of which are toxic. Finding cleaner ways to produce
solar panels will be important as more are produced.
Solar Thermal Electric
Generation
Systems that concentrate solar en-
ergy to heat fluids have long been
used for buildings and indus-
trial processes. In solar thermal
electric generation, electricity is
produced by systems that collect
solar thermal
electric
generation
A means of producing
electricity in which
the sun’s energy is
concentrated using
mirrors or lenses onto
a fluid-filled pipe; the
heated fluid is used to
generate electricity.
Direct Solar Energy 447