Solar thermal power –
­Lebrija
Special report 1
Focus on
innovation-driven
growth markets
In less than six hours, the sun generates
enough energy in the earth’s deserts to
meet the electricity needs of all the people
on our planet for an entire year.
Thanks to solar thermal technology, this
energy can now be reaped without producing CO2 emissions. Siemens’ first solar
thermal plant will start feeding electricity
into Spain’s power grid in 2011.
On land once occupied by a cotton plantation, some
170,000 mirrors are now being installed to capture
the sun’s energy. This solar thermal facility will
be able to supply about 50,000 Spanish households
with carbon-free electricity.
Avi Brenmiller, CEO of our Solar Thermal Energy
­Business Unit, is a pioneer in the field of solar
­thermal power. He and several other leading experts
are now working for Siemens to optimize this
­technology.
“Siemens is focusing on innovation- and technology-driven
growth markets. One prime example here is solar thermal
power, which offers tremendous potential for providing clean
energy in the future. Our new solar thermal power plant in
Lebrija demonstrates the feasibility of this leading-edge technology. By harnessing the sun’s energy, we’ll soon be providing about 50,000 households with carbon-free electricity.”
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Avi Brenmiller, Solar Thermal Energy Business Unit
170,000
individual parabolic mirrors ready for action
The curvature of the mirrors
installed at the Lebrija power plant
is calculated down to a fraction of a
degree, maximizing the amount of
solar energy that can be captured.
Siemens engineer Moshe Shtamper
notes, “The more precisely we work,
the higher the plant’s ­efficiency and
the greater the CO2 reduction.”
400
degrees Celsius
That’s the temperature that can
be reached by the thermal oil in
the receiver tubes where the
sun’s heat is concentrated. The
hotter the oil, the more efficient
the plant.
The individual components were manufactured at
­high-tech production facilities before being shipped to
Lebrija for final plug-and-play assembly – thus eliminating the need for costly and time-consuming construction on site. Modular design is important if power
plants are to be built on a large scale with the help of
local laborers in regions like the rocky deserts of North
Africa.
If lined up end-to-end, the parabolic mirrors installed
in Lebrija would extend some 60 kilometers.
Siemens’ portfolio boasts nearly all the components and systems needed for solar thermal power plants – including the
solar collectors that concentrate the sun’s energy, the control
technology and the power plant unit, in which a steam turbine
and a generator convert thermal energy to electric power.
In addition, our electrical and automation technologies enable
the efficient production of high-quality mirrors and receivers
for the solar collectors.
Today, there’s no question that solar thermal power is a
­viable technology; the challenge now is to cut costs. Siemens
has greatly expanded its expertise in solar thermal energy,
for example, by acquiring the specialist provider Solel at the
beginning of fiscal 2010. Leading experts in the field are now
hard at work at Siemens, researching ways to improve mirror
coatings and optimize the receiver tubes that transport
­t hermal oil. Tubes from Siemens are already setting records
for efficiency. And higher efficiency means greater use of solar
thermal energy – and more power plant projects.
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50
megawatts of carbon-free electricity
That’s enough ecofriendly power
to meet the needs of about 50,000
Spanish households.
Reaping the sun’s
energy with solar
thermal technology
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 consumed 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 exchanger, 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 Lebrija plant will soon be generating enough electricity
to meet the needs of roughly 50,000 Spanish households.
Solar thermal power plants – also known as concentrated solar power (CSP) plants – are being constructed 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 required for solar thermal power plants. Instead,
­ irrors concentrate the sun’s energy to heat oil.
m
This heat is transferred to water, which then evap­
orates. The resulting high-pressure steam drives a
turbine which – via a generator – converts mechanical energy into electricity.
In extremely sunny regions such as the Sahara, CSP
plants operate very efficiently – unlike photovoltaic
systems, whose efficiency declines in hot environments. Solar thermal technology enables heat to be
stored in accumulators for several hours so that it
can be converted to electricity even at night. Capable of producing electricity at regular, predictable
intervals, CSP plants – like their fossil-fuel counterparts – 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 intends to increase the amount of power generated at
CSP plants to 2,000 megawatts – an amount equivalent 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 envisions 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
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