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SOLAR THERMAL ELECTRIC AND HOW TO START IT AS A
“FREE LUNCH”
December 18, 2005
by Sol Shapiro,
I have been trying to move the renewable energy world on what I
consider the right path - reducing the cost of capital for the last
10 years since I retired from my career in program management in the
aerospace world.
We should be moving ahead on renewables for 3 reasons: to reduce
pollution, to create an energy base to compete economically with
fossils and thus keep costs from escalating and in the long run to
create a long term solution to global warming.
Both economic and the global warming issues require that we look at
resources which have the capacity to replace the total U.S. energy
base of about 100 Quads.
No combination of today’s renewables have this capacity without a
major contribution from solar; and solar alone can provide all of
this energy on about 60,000 square miles (~2% of the area of the
lower 48 states) of good insolation in the Southwest.
Another significant issue is one of dispatchability - providing energy
on demand. Today’s primary renewables of choice, wind and
photovoltaics are intermittent; and while this is no issue when they
provide only a small percent of energy, an approach is needed for
long-term growth to provide dispatchability. Energy storage is
possible - but at added cost. But there is a solar technology that
has built in storage - solar thermal in which the sun’s thermal
energy is collected and stored in a liquid medium; and this heat
energy is then used to drive conventional generators similar to
those used by fossil plants. And such facilities can in fact be
integrated with fossil plants to guarantee dispatchability by use of
storage backed up with fossil energy when storage capacity is outrun
by cloudy weather.
Solar thermal electric generation is well tested with about 350
megawatts operational in California for the past 20 years; and
integrated with fossil generation. These facilities were built in a
time frame when California energy generation was regulated; and
their added cost was approved under those rules. And while the cost
of energy generation of these existing facilities is well below that
for PV, no new plants have been built - because their cost is
currently well above that for fossil plants. Studies predict that
when about 4000 megawatts of solar thermal is deployed it is
expected to become competitive with fossil generated energy.
At present, PV has benefited greatly from RPS, but solar thermal
plants have not been built -- BECAUSE THEY NEED ABOUT $150 MILLION
per facility (for a 50 mw plant) until very recently. (A facility is
now under construction in Nevada under RPS.)
But there is a way to get the process moving again without RPS; AND
WITHOUT COST TO RATEPAYERS OR TAXPAYERS. This process takes
advantage of the ability of solar thermal to integrate with fossil
plants (existing or new); and requires that the states provide loan
guarantees to write down the cost of capital associated with the
cost of the solar thermal facilities. To create these loan
guarantees, legislation will be required; and that is where your
help is needed.
Simply stated build a 50 megawatt solar thermal plant into a fossil
facility (coal or natural gas) and increase the debt ratio to about
65% for the entire facility from the nominal 50% using loan
guarantees to keep the cost of capital constant. VOILA, A “FREE
LUNCH”; ENERGY AT FOSSIL PRICES FROM SOLAR.
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