A summary of Darshan Goswami’s views on Solar CSP’s role in India’s future:
Solar energy is an enormous resource readily available in all countries throughout the world. Concentrated solar power plants have been used in California since the 1980s. Pacific Gas & Electric has recently signed contracts to buy 500 MW 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.The Solana 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 satisfy 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.
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 large scale initiatives, like Europe’s DDI, are needed to make it more cost effective.
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.
With the right programs and policies today, India can have a great deal of control over how rapidly solar power becomes cost-competitive. 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.
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