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How Concentrated Solar Power Can Meet India’s

Future Power Needs


By Darshan Goswami, M.S., P.E.

Introduction

Solar energy is an enormous resource that is readily available in all countries throughout the
world, and all the space above the earth. Long ago scientists calculated that an hour’s worth of
sunlight bathing the planet held far more energy than humans worldwide could consume in a
year. I firmly believe that India should accelerate the use of all forms of Renewable Energy
(photovoltaic, thermal solar, solar lamps, solar pumps, wind power, biomass, biogas, and hydro),
and more proactively promote Energy Efficiency. However, in this article, I will only focus on
the use of Concentrated Solar Power (CSP) technology to meet India’s future energy needs.

The Sun: Goldmine of green energy

Concentrated solar power plants have been used in California, USA since the 1980s. More
recently, Pacific Gas & Electric has signed contracts to buy 500 megawatts of solar thermal
power from two solar companies. First, NextEra Energy Resources will sell 250 megawatts of
CSP generated power from the Genesis Solar Energy Project to be located in Riverside,
California. Second, Abengoa’s Mojave Solar project will supply the remaining 250 megawatts
from a plant located in San Bernardino County, California. Subject to California Public Utility
Commission approval of the power purchase agreements, construction of these solar energy
generating plants is expected to start in 2010 with operations planned to begin in 2013. Both
these solar thermal power projects will contribute to meeting California’s aggressive Renewable
Portfolio Standard, which calls for moving away from fossil fuels to solar and other renewable
energy sources that avoid pollution and greenhouse gas emissions.

In addition to California, the sunny state of Arizona, USA has become home to the world's
largest Solar Plant. Solana (which means “a sunny place” in Spanish) solar power generating
station is scheduled to begin operation in 2012, harnessing Arizona’s most abundant renewable
energy resource - the sun. This plant (located 70 miles southwest of Phoenix) has a projected
capacity of 280 megawatts, and will make use of Abengoa Solar's CSP technology.

Courtesy: Proposed Solana Generating Station Project (concentrating solar power project) in Arizona

Worldwide, Germany and Spain are leaders in solar power generation with 4,000 megawatts and
600 megawatts of installed capacity respectively. A recently formed consortium of 12
companies, known as the Desertec Industrial Initiative (DDI), plans to spend 400 billion Euros
($557 billion) to extract solar energy from the Sahara desert. The DDI aims to deliver solar
power to Europe as early as 2015 and eventually provide 15% of Europe's electricity by 2050 or
earlier via power lines stretching across the desert and under the Mediterranean Sea.

The vast Rajasthan Desert is very similar to the Sahara desert in Africa, and has the potential to
become the largest solar power plant in India. Due to high levels of available sunlight, CSP
plants in Rajasthan could begin satisfying most of India’s energy needs in just few years. India’s
potential benefits from solar power are as numerous as the sands of Rajasthan desert, and include
reduced dependence on fossil fuels and a cleaner environment. These benefits can be realized by
installing renewable energy technologies, such as CSP, to protect the environment while
diversifying energy resources and helping to lower prices. Solar power can also reduce strain on
the electric grid on hot summer afternoons, when air conditioners are running, by generating
electricity where it is used. India has optimal conditions to use CSP to harness solar energy from
the Rajasthan Desert. However, to take advantage of this innovative technology, potential CSP
plant sites must be identified and deployment accelerated. Specifically India needs to heavily
subsidize Solar and Wind Power projects just like Japan, Germany and other European nations
are doing. The use of renewable energy has great potential to create more jobs in India
especially in the rural areas.

How the Technology Works


CSP plants generate electricity from sunlight by focusing solar energy, collected by an array(s)
of sun-tracking mirrors called heliostats, onto a central receiver. Liquid salt (a mixture of
sodium nitrate and potassium nitrate) is circulated through tubes in the receiver, absorbing the
heat energy gathered from the sun. The heated salt is then routed to an insulated tank where it
can be stored with minimal energy losses. To generate electricity, the hot molten salt is routed
through heat exchangers and a steam generation system. The steam is then used to produce
electricity in a conventional steam turbine. After exiting the steam generation system, the now
cool salt mixture is circulated back to the “cold” thermal storage tank, and the cycle is repeated.

Courtesy Abengoa: A Utility-scale concentrated solar power (CSP) plant

While CSP technology is not new, it offers one of the most promising utility-scale, and
sustainable technology options for meeting India’s energy needs from renewable energy
resources. But a large scale initiative (like Europe’s DDI) is needed to make it more cost
effective. Moreover, the Rajasthan desert has the potential to produce solar power at a cost low
enough to be competitive with fossil and nuclear power.

Conclusion

Solar power is an enormous readily available source of energy. It can be used everywhere, and
can, in principal, satisfy most of India’s energy demand from a renewable, safe and clean
resource. Concentrating solar collectors are very efficient and can completely replace the
electricity traditionally produced by fossil fuel power plants. CSP plants in the 30 MW to 200
MW range are now operating successfully in locations from California to Europe. Nearly every
day now, new CSP plants are being planned for construction. Today's CSP plants supply the
heat needed to generate electricity at a cost equivalent to $50 - $60 per barrel of oil. This cost is
expected to be slashed by 50% to below $25 - $30 per barrel in the next 10 years.

India should begin creating a mainstream solar energy market with the goal of making solar
power cost-competitive with fossil fuel-generated electricity. One step toward achieving this
goal would be to start a nationwide solar initiative of building 10 million solar roofs within ten
years. It has often been said that it is not a question of if, but when solar power becomes cost-
competitive with traditional electricity sources. With the right programs and policies today,
India can have a great deal of control over how rapidly solar power becomes cost-competitive.
And, by getting in on the ground floor of this new technology, India can also create millions of
jobs in renewable energy.

India needs a plan with the same spirit, boldness and the imagination of the Apollo Program that
put astronauts on the Moon. The technology is well established and available. All that is needed
now to make this concept a reality is political commitment and appropriate investments and
funding to harness this renewable solar energy resource.

I expect that the new US Administration will strongly prioritize the use of solar thermal energy
as a solution to the climate and energy crisis. This should create additional incentive for
countries such as India, who have optimal conditions for CSP plants, to take similar actions.

India’s solar energy holds great promise. India must accelerate its investment in Renewable
Energy resources, specifically solar and wind energy. The U.S.-India Energy Dialogue, which
facilitates discussions on renewable energy and energy efficiency, can be a very useful tool to
spark investments in solar energy. This can lay the foundation for an energy independent future
- one in which the Government of India takes advantage of the vast amounts of energy available
from the Rajasthan Desert sun (instead of oil from the Arab nations) to power its future energy
needs. In addition, solar energy would not only create millions of jobs, but also sustain India’s
positive economic growth, help lift its massive population out of poverty and combat climate
change.

The views and opinions expressed in this article are solely those of the writer and are not
intended to represent the views or policies of the United States Department of Energy. The
article was not prepared as part of the writer's official duties or using any Government
resources at the United States Department of Energy.

About the Author:


Darshan Goswami has over 35 years of experience in the energy field. He is working for United
States Department of Energy (DOE) as a Project Manager in Pittsburgh, PA, USA. He retired
as Chief of Energy Forecasting and Renewable Energy from the United States Department of
Agriculture (USDA) in Washington, DC. Earlier, he worked for 30 years at Duquesne Light
Company, an electric utility company in Pittsburgh, PA, USA. He is a registered Professional
Electrical Engineer with a passion and commitment to promote, develop and deploy Renewable
Energy Resources and the Hydrogen Economy.

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