Siemens 2010 Annual Report Download - page 25

25
By 2050, solar thermal power
plants and wind farms in North
Africa and the Middle East
could be not only meeting all
local electricity requirements
but also providing more than
15 percent of the power con-
sumed in Europe.
“Everything here is in motion,” says Moshe
Shtamper, surveying Siemens’ new solar thermal
power plant in Lebrija, Spain. Pointing to one of the
pipes that transport hot thermal oil to the heat ex-
changer, Shtampter explains, “The tubes expand
when heated, the mirrors align themselves with the
sun, the steam turbine rotates. Sometimes this
plant seems like a living thing to me.” The “living
thing” the Siemens engineer is talking about is
located some 60 kilometers south of Seville, in
Andalusia. Cotton used to be grown on these fields.
Shtamper’s team waited until the last harvest was
in to begin work. Now it’s putting the finishing
touches on the facility, which will go into operation
in 2011. With a capacity of 50 megawatts, the Leb-
rija plant will soon be generating enough electricity
to meet the needs of roughly 50,000 Spanish house-
holds.
Solar thermal power plants – also known as concen-
trated solar power (CSP) plants – are being con-
structed at many other locations worldwide. They
operate on a different principle than photovoltaic
facilities, which convert solar radiation directly into
electricity using silicon cells. No costly silicon is re-
quired for solar thermal power plants. Instead,
mirrors concentrate the sun’s energy to heat oil.
This heat is transferred to water, which then evap-
orates. The resulting high-pressure steam drives a
turbine which – via a generator – converts mechan-
ical energy into electricity.
In extremely sunny regions such as the Sahara, CSP
plants operate very efficiently – unlike photovoltaic
systems, whose efficiency declines in hot environ-
ments. Solar thermal technology enables heat to be
stored in accumulators for several hours so that it
can be converted to electricity even at night. Capa-
ble of producing electricity at regular, predictable
intervals, CSP plants – like their fossil-fuel counter-
parts – can help offset supply fluctuations from
wind power and photovoltaic installations.
These advantages explain why numerous North
African countries are now investing in solar thermal
power. For example, by 2020, Morocco alone in-
tends to increase the amount of power generated at
CSP plants to 2,000 megawatts – an amount equiva-
lent to the capacity of two large conventional power
plants. This resource-deprived country – which
currently imports nearly all its energy – could some
day be exporting solar power to Europe. That’s also
the idea behind DESERTEC, an initiative that envi-
sions an entire network of power plants generating
electricity from renewable sources across North
Africa and the Middle East. By 2050, more than
15 percent of Europe’s electricity requirements
could be met with the help of the sun and the wind.
“In the wind power business, Siemens demonstrated
years ago how a green, leading-edge technology
could be turned into a lucrative business within
only a few years. Now we’re poised to do the same
in the field of solar energy,” says René Umlauft, CEO
of Siemens’ Renewable Energy Division. And there’s
no doubt that the market for solar thermal power
plants is just as abuzz with activity as the plants
themselves.
www.siemens.com/lebrija
Reaping the sun’s
energy with solar
thermal technology