Solar Power Coming to a Boil
Jan 31, 2009 - USA Today
After emerging in 2006 from 1 5 years
of hibernation, the solar thermal power industry is
experiencing a resurgence, with plenty of new capacity
coming online worldwide. During the 1990s, cheap fossil
fuels, combined with a loss of state and Federal incentives,
put a damper on solar thermal power development However,
recent increases in energy prices, escalating concerns
about global climate change, and fresh economic incentives
are renewing interest in this technology. Considering
that the energy in sunlight reaching the Earth in
just 70 minutes is equivalent to annual global energy
consumption, the potential for solar power virtually
is urilirnited. With concentrating solar thermal power
(CSP) capacity expected to double every 16 months
over the next five years, worldwide installed CSP
capacity will reach 6,400 megawatts in 2012 - 14 times
current capacity.
Unlike solar photovoltaics (PVs), which
use semiconductors to convert sunlight directly into
electricity, CSP plants generate electricity using
heat Much like a magnifying glass, reflectors focus
sunlight onto a fluid-filled vessel. The heat absorbed
by the fluid is used to generate steam that drives
a turbine to produce electricity. Power generation
after sunset is possible by storing excess heat in
large, insulated tanks filled with molten salt Since
CSP plants require high levels of direct solar radiation
to operate efficiently, deserts make ideal locations.
Two big advantages of CSP over conventional
power plants are that the electricity generation is
clean and carbon-free and. since the sun is the energy
source, there are no fuel costs. Energy storage in
the form of heat also is significantly cheaper than
battery storage of electricity, providing CSP with
an economical means to overcome intermittency and
deliver dispatchable power.
The U.S. and Spain are leading the world
in the development of solar thermal power, with a
combined total of more than 5,600 megawatts of new
capacity expected to come online by 2012. Representing
over 90% of the projected new capacity in that span,
the output from these plants would be enough to meet
the electrical needs of more than 1,700,000 homes.
The largest solar thermal power complex in operation
today is the Solar Electricity Generating Station
in the Mojave Desert in California. Coming online
between 1985 and 1991, the 354megawatt complex has
been producing enough power for 100,000 homes for
almost two decades. In June 2007, the 64- megawatt
Nevada Solar One plant became the first multi-megawatt
commercial CSP plant to come online in the U.S. in
16 years.
Today, more than a dozen new CSP plants
are being planned in the U.S., with some 3,100 megawatts
expected to come online by 2012. Some impressive CSP
projects in the planning stages include the 553- megawatt
Mojave Solar Park in California, the 500-megawatt
Solar One and 300-megawatt Solar Two projects in California,
a 300-megawatt facility in Florida, and the 280-megawatt
Solana plant in Arizona.
In Spain, the first commercial-scale
CSP plant to begin operation outside the U.S. since
the mid 1980s came online in 2007: the 11megawatt
PS10 tower. The tower is part of the 300-megawatt
Solucar Platform, which, when completed in 2013, will
contain 10 CSP plants and produce enough electricity
to supply 153,000 homes while preventing 185,000 tons
of carbon dioxide emissions annually. All told, more
than 60 plants are in the pipeline in Spain, with
2,570 megawatts expected to come online by 2012.
Economic and policy incentives partly
are responsible for the renewed interest in CSP. The
incentives in the U.S. included a 30% Federal Investment
Tax Credit (TTC) for solar through the end of 2008,
which has good prospects for being extended. Moreover,
the Renewable Portfolio Standards hold sway in 26
states. California, for instance, requires that utilities
get 20% of their electricity from renewable sources
by 2010, and Nevada requires 20% by 2015, with at
least five percent from solar power. In the Southwest,
the cost of electricity from CSP plants (including
the Federal ITC) roughly is 13 to 17 cents per kilowatt-hour,
meaning that CSP with thermal storage is competitive
today with simple-cycle natural gasfired power plants.
The Department of Energy aims to reduce CSP costs
to seven to 10 cents per kilowatt-hour by 2015 and
to five to seven cents by 2020, making CSP competitive
with fossil-fuel based power sources.
Outside the U.S. and Spain, regulatory
incentives in France, Greece, Italy, and Portugal
are expected to stimulate the installation of 3,200
megawatts of CSP capacity by 2020. China anticipates
building 1,000 megawatts by that time. Other countries
developing CSP include Australia, Algeria, Egypt,
Iran, Israel, Jordan, Mexico, Morocco, South Africa,
and the United Arab Emirates.
A study by Ausra. a solar energy company
based in California, indicates that more than 90%
of fossil fuel-generated electricity in the U.S. and
the majority of U.S. oil usage for transportation
could be eliminated using solar thermal power plants
- and for less than it would cost to continue mipotting
oil. The land lecjuirement for the CSP plants would
be roughly 15,000 square miles (the equivalent of
15% of the land area of Nevada). While this may sound
like a large tract CSP plants use less land per equivalent
electrical output than large hydroelectric dams when
flooded land is included, or than coal plants when
factoring in land used for mining. Anotiier study,
published in Scientific American, proposes using CSP
and PV plants to produce 69% of U.S. electricity and
35% of total U.S. energy, including transportation,
by 2050.
Copyright Society for Advancement of
Education Jan 2009
(c) 2009 USA Today; New York. Provided
by ProQuest LLC. All rights Reserved.
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