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Solar Thermal Electric Power Plants Throughout MENA


After Gutenberg
December 4, 2007


Solel and FPL Energy operate in the Mojave Desert in Southern California the 354
MW, SEGS (Solar Energy Generating Systems). Not only the largest operational
solar thermal energy system, but also the largest solar power system of any
kind, SEGS is a trough system.

From Renewable Energy Access1 we learn that “harnessing the sun’s energy falling
on just 6,000 square kilometers of desert in North Africa would supply energy
equivalent to the entire oil production of the Middle East of 9 billion barrels a year.”

The German Aerospace Center made this estimate based upon the power generated by
solar thermal electric power plants “of between 50 and 200 MW in size in
different locations across North Africa.”

The study calculated that solar thermal power plants could supply 68 percent
of North Africa’s as well as Europe’s electricity by 2050. Cables to transmit
electricity from North Africa to Europe have already been built under the sea.

Who knows, staff at the center might even appreciate the United Arab Emirates
using the billions acquired for their oil to develop new, renewable energy sources.

Solel Diagram

In any case, such a report comes at a time when significant development of CSP
(Concentrating Solar Power) is underway in Spain. As previously noted, SyV
(Sacyr-Vallehermoso), one of the largest Spanish infrastructure corporations, is
undertaking three solar power plants in Spain with a total capacity of 150 MW
and a total overall investment of $890 million. An estimated $500 million will
go to the supplier of the technology. Solel parabolic trough thermal technology
has been responsible for continuous production of utility scale power in
California’s Mojave Desert over the last twenty years.

The RE article used the German proposal as a way to mention Flabeg, “a
German-based manufacturer of parabolic trough mirrors for solar thermal power
plants. The company recently developed a mirror that can reflect 93 percent of
the sun’s rays.” Flaberg wants to sell high precision mirrors, which can
concentrate the solar power onto an absorber tube with a diameter of 70 mm or
less, in the solar thermal power plant market arising in Spain and North Africa.
The company is set to deliver 210,000 of the high precision mirrors to the 50
megawatt (MW) solar thermal power plant Andasol II, in Spain—the biggest in
Europe—by the end of June 2008… Flabeg has already equipped the 50 MW Andasol
I solar thermal plant with 210,000 RP 3 mirrors.

Flaberg is using the precision of their reflectors as a selling point. The
author of the article, Jane Burgermeister, states that one of these 50 MW solar
power plants can generate an estimated, “5 million kilowatt-hours more of
electricity for every extra 1 percent of sunlight that is collected by solar
mirrors.” (One would assume that estimate is based upon the expected lifespan of the installation.)

RE commentator E.V.R. Sastry notes that the extremely transparent, white type of
glass improves the overall reflectivity of the mirror since the light first must
pass through the glass. As the light then is reflected by a coating on the back
of the glass sheet and passes back through the glass, the shape of the reflector
focuses the reflected light on the collector.

Parabolic troughs that concentrate solar radiation onto evacuated tube
collectors are commonly used for utility-scale solar thermal electric power
plants. The collector tube is enclosed by glass and the space within the tube is
maintained at a permanent vacuum, thereby reducing conductive heat loss at high temperature.

Optical characteristics are critical to design, manufacturing, operation and
maintenance of the solar field, particularly when required to build a
utility-scale solar thermal electric power plant. There is a trade-off because
of cost. (See 2007 National Renewable Energy Laboratory report on estimations of
material costs2. The report compared polished aluminum, thin mirrored glass and
silvered polymer film coated aluminum, all of which can make use of recycled
materials.) Not only must developers consider reflective ability, but also
congruency with design of the support structure and durability over the expected
life of the facility. Some prefer metal reflectors because of their lower cost.

Vinod Khosla, an advocate for and investor in solar thermal electric power, has
noted that “worldwide, the electric power industry creates 40 percent of total
carbon emissions, and electricity use is rapidly growing.” Large-scale,
affordable sources of clean power are needed “to meet the dual challenges of
economic growth and carbon constraints.” Khosla also has advocated for
development of the interconnected electricity system between regions, power
brokers, etc. Sophistication in power generation needs to be equaled by elegance
in distribution for CSP to be effective.

Arid, semi-desert areas of the world, where there has been the most development
of utility grade thermal solar electric power, include Spain, Israel and the
Southwestern United States. The Trans-Mediterranean Renewable Energy Cooperation
proposes that concentrating solar thermal power stations in the Middle East and
North Africa could export electricity to Europe

RE commentator Hussain Alrobaei reminds its readers that MENA (the Middle East
and North Africa) is one of the principle regions around the globe that benefits
from a higher solar radiance.

There will be a significant market for producing solar electricity under the
ideal meteorological conditions in the sunbelt countries of the MENA and
transferring part of this electricity to Europe. As proposed recently by the
Trans-Mediterranean Renewable Energy Cooperation, concentrating solar thermal
power stations in MENA could be used for export electricity to Europe as well
as for providing regional freshwater from combined thermal desalination of sea
water [1,2]. The electricity produced in CSP plants can be used for domestic
needs and export, as well as for additional desalination of sea water through
reverse osmosis (RO), if required. The design of such combined solar power and
desalination plants can be flexibly adapted to any required size and need. CSP
plants can be designed from 5 MW to several 100 MW capacity [3]. Therefore, in
the future European mix of energy sources for power generation, CSP can serve
to cover base load, intermediate load or peaking load and even to compensate
the fluctuations of PV and wind power.

References

1. Hussain Alrobaei , 2007, Novel Integrated Gas Turbine Solar Cogeneration
Power Plant/DEC, Halkidiki, Greece ,22–25 April 2007.
2. Hussain Alrobaei , 2006 , Repowering and Modification of Grid Connected
Reverse Osmosis Desalination Plants/CIERTA 2006 , Exposiciones y Congresos -
Roquetas de Mar (Almería).
3. Hussain Alrobaei,2006, Integrated Gas Turbine Solar Power Plant/ The Energy
Central Network/ energycentral.com/centers/knowledge/whitepapers.
1Germany Looks to North Africa's Untapped Solar Thermal Potential
2Parabolic Trough Collector Overview (PDF)
This entry was written by jcwinnie, posted on 2007-9-28 at 4:28 pm, filed under
design, development, economics, energy, forecast, geography and tagged
distributed generation, electric power, solar power, thermodynamics. Bookmark
the permalink. Follow any comments here with the RSS feed for this post.

RANDOM QUOTE:

In 2000 power stations accounted for the greatest percentage of anthropogenic
carbon emissions, 29.5%. In the U.S. the amount of carbon dioxide from coal
plants has gone up about twenty-seven percent since 1990, and these carbon
emissions are continuing to go up.

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