By Darshan Goswami, M.S., P.E.
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.
Concentrated solar power plants have been used in California 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, Calif. Second, Abengoa’s Mojave Solar project will supply the remaining 250 megawatts from a plant located in San Bernardino County, Calif. 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 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.
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 a 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.
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.
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, Pennsylvania. 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.