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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, 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.
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.
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.
For information on purchasing reprints of this article, contact sales. Copyright 2013 CyberTech, Inc.
And people, the discussion is Solar Thermal. if ANYONE tries to drag this discussion off into solar PV .......
Harry Valentine 4.1.10
India has tremendous potential to make great strides in the area of cost-competitive renewable energy and especially concentrated solar thermal power (CSTP). Advances in high-temperature CSP (1000-deg C) can allow for the operation of externally-heated air turbine engines. India's aluminium industry can provide a mixture of bauxite and cryolite (molten eutectic compound) to store hihg-temperature thermal energy to continue operating the turbines until after sunset.
There is also potential for India to import CSP from the Saudi Arabian desert region at some time in the future, courtesy of an undersea power cable between Oman and the Gulf of Kutch. CSTP can also allow for solar air-cycle and solar-steam power plants to dump exhaust heat into desalination plants along the coast or at inland locations, dump the heat into solar towers (another air-cycle solar thermal technology).
CSP and CSTP definately have a future in India . . . . and especially with the cost of both expected to decline in the future.
bill payne 4.6.10
We've been alerted by MorganStanley vp Bill Batie that large scale solar generation of electrcity may be a fraud.
Volts on the vertical axis and amps on the horizontal axis may equal power?
We are speculating, of course.
Let's see what happens.
Don Hirschberg 4.6.10
Here is how I understand the situation in India.
Some 300 to 400 million Indians have no electric service what-so-ever, not even lighting. The other 800 million or so have mostly spotty service and industries frequently have to shut down and send people home for lack of electricity. If you are moneyed or absolutely need reliable service you buy your own diesel powered generator. Several hundred million cook their food using gathered twigs.
I don't have the latest figures at hand but my memory says over 80% of electricity is coal generated.
New coal mines are being opened up in India and India is buying coal mines(companies) in other countries. In recent months coal supplies at generating plants were at desperately low level, some a few days from forced shutdown.Coal usage continues to increase, new coal fired power plants are expected to burn more, not less, over at least the next sixty years.
India's excessive population is still growing, their ultimate impediment. Their population is expected to exceed China's in only a decade or so. Despite building many new coal burners, the cheapest and quickest way to get electricity to the population, it's been a losing battle,
So now they are going to be saved by more expensive solar power. Without anything close to baseload capacity or grid capacity. According to my childhood Mother Goose Book, "If wishes were horses beggars would ride." .
Don Hirschberg 4.6.10
I found my 2008 coal data. Above I should have said 68% for India, sorry - it's China that generates "over 80%" of its electricity from coal. India's domestic coal production in 2008 was third, behind China and the US. India also imports coal.
Len Gould 4.7.10
Gosh, these threads deterioriate into opinion and worse quite rapidly.
Edward Reid, Jr. 4.8.10
These threads are triggered by opinion. :-)
Herschel Specter 4.8.10
In addition to the valid comments about the need to have a complete infrastructure-a grid system and end uses that run on electricit- there appears to be other defects in this enthusiastic forecast of concentrated solar energy (CSP). The most important concern is the lack of water in the desert for an ultimate heat sink. An article in Scientific American in 2008 "A Grand Plan for Solar Energy" made arguments similar to that of the author's where a huge solar facility was proposed for location in the Arizona desert. When pressed to explain what ultimate heat sink might be available in the desert, the authors conceded that their concept would require 275 of the world's largest desalination plants stretching from California's coastline, down through Mexico's Baja California peninsula and then over to Texas to produce 13 billion cubic meters of water needed per year. The same authors acknowledged that it would take about 100 rail lines to deliver this water to the many cooling towers in the desert that would be needed. Not discussed is the environmental effects of releasing such a huge amount of water or if the mist that they would produce would diminish the solar energy to be collected nearby. To avoid this environmental monstrosity one could use air as the ultimate heat sink at an economic penalty, particularly during the very hot summer days in the desert- precisely the time when air conditioning would be peaking. To my knowledge no one yet has built a CSP plant that uses air as the heat sink.
The other issue with large scale CSP concepts is the diurnal and seasonal variations in the collection of solar energy. The sun goes down every night so when the author lists the electrical output of a CSP plant it may be the peak output during the best hour of the year. As an approximate rule of thumb, the 24 hour average output, assuming the plant could run for 24 hours, would be about 25% of the peak value.
Not only are there diurnal variations in insolation, there are seasonal ones as well. A CSP plant in winter will only have about half of the output it has in the summer. How will this shortfall be overcome?
Finally, present designs are indeed turning to the use of molten salt compounds as the working heat transfer fluid. By storing some of this hot molten salt it may be able to shift some of the collected solar energy to more hours in the day, but at a comparable reduction in electrical output during the peak collection time periods. Figures like six hours extension in the time that the plants can put electricity on the grid are being talked about. However, this same salt heat tranfer fluid has a freezing point about the boiling point of water. Because of this, the salt fluid has to be drained each night and stored in an insultated structure and the whole system has to be refilled each following day.
Lastly, whenever the CSP plant is inoperable-each night- its dedicated transmission lines are also unused. This is an expensive way to operate a transmission grid system.
CSP plants may have a role to play in the future, but it could be a very limited one until the above problems are resolved and the resultant cost of electricity low enough to be competitive.
Herschel Specter email@example.com
Don Hirschberg 4.9.10
Herschel, I was happy to see some real numbers in your comment. Quite educational. Thank you. Air cooling at the daytime high temperatures in the otherwise nost attractive locations for solar is indeed a problem and seriously limits the thermal efficiencies attainable. I have not attempted a real number calculation but I suspect air cooling to be very expensive. Perhaps a two medium/stage heat sink air/water might be viable?
Len Gould 4.9.10
"an ultimate heat sink" -- The obvious solution, though no developer thus far has determined it necessary, is to use a medium other than water (eg. any of several common refrigerants) in the turbine circuit to allow the condenser to operate efficiently at the higher temperature of ambient air, or to allow a large reservoir of standing salt water to absorb the heat effectively without needing to evaporate any high percentage of it, eg. low-rate replacement with a small pipeline from the ocean.
"A CSP plant in winter will only have about half of the output it has in the summer. How will this shortfall be overcome?" -- By the obvious means of providing low-cost thermal backup from fossil generation, either natural gas or coal. The lowest investment cost is direct-fired heating of the thermal transfer / storage medium during low-insolation periods, though more efficient no doubt would be the more capital-intensive use of a combustion turbine with the exhaust heat used to heat the thermal medium. All CSP plans, esp. those which in future may be targeted to baseload, provide for this variation in their economic models, and still work as advertised.
"the salt fluid has to be drained each night " -- of course it does, and that is now being done at all the sites which Sargent and Lundy's evaluated in coming up with their analysis referenced above.
Honestly, in your entire criticism there is not a single point which can possibly have any novelty to anyone like NREL or Sargent and Lundy's engineering, who've determined that your conclusions are simply wrong.
Len Gould 4.9.10
Sorry, that should have been addressed to Herschel, not Don.
Don Hirschberg 4.9.10
I presume this solar heat is intended to make steam to run a turbine. In other words, a Rankine Cycle plant.
The only energy that can be used to do work is that which is above the available sink temperature. (Power plants generally have a better e in the winter.) The thermal efficiency, e, of a condensing turbine depends on the pressure (vacuum) of the exhaust which is fixed by the condensing temperature. A condenser temperature of 100 F corresponds to an exhaust pressure of 1 psia. Less, an inch of Hg is better.
Obviously daylight desert air is frequently over 100 F so even an infinitely large air condenser cannot provide us low exhaust pressures. Maybe at some point we might hear that the sun is free so let the e slide?
So no matter how it's done the sink (environment) has to take all the rejected heat. I roughed out that If water is the cooling medium about 8 or 9 pounds of water has to be evaporated (lost) per kWh generated. This is what you see rising and causing plumes rom cooling towers on buildings and power plants.
Use of a "refridgerant" would not eliminate the heat sink problem. I can't see how it could do anything but make it woarse.and consume energy, with even more heat to get rid of.
A large salt water pond would would have to lose not only the 8 or 9 pounds of water/kwh through evapoation but have enough additional evaporation to keep from gaining temperature from sunshine. If the water added to the pound was salt water you would soon have youself a salt flat
i have been careless about the word desert. What we are talking about here is a special kind of desert - the kind like the Sahara, not the kind like much of Antarctica.
Herschel Specter 4.10.10
Len, Thank you for your comments. I do not claim originality in my comments, but it is clear that some of the readers may be unaware of these issues/history. Your suggestion to use a fossil fueled plant to overcome the limited solar insolation,especially in the winter, seems to trade off reliability of supply for more GHG released to the environment, thereby compromising one of the reasons that we are interested in solar thermal in the first place. I assume that the fossil plant will need its own heat sink,but air cooling at night might be sufficent. What is missing from this conversation are cost estimates and perhaps you can supply them. What would be the cost for electricity for a CSP/fossil plant where both pieces- are idle part of the time- or did you intend to run the fossil plant 24/7? Please include the cost of the dedicated transmission line from the desert location to the main grid system. Thank you. Herschel
Len Gould 4.11.10
Don: "Use of a "refridgerant" would not eliminate the heat sink problem. I can't see how it could do anything but make it woarse" -- I think you are supposing I propose a refrigeration circuit for the condenser. I do not. I propose, instead of water/steam, using a working fluid in the main turbine circuit which condenses at a much higher temparature than water at 1' HG pressure, allowing the turbine to maintain an efficient condenser at significantly higher condenser temperatures. Agreed its still not as efficient as water / steam due to the smaller difference between hot and cold temperatures than a modern boiler plant, but still a linear relationship.
Obviously a cooling pond would need to be shaded, perhaps best by solar collectors plus some auxiliary means. Development of the salt flat would be an expected design feature.
Don Hirschberg 4.11.10
Back on 4.9.10 in a post I roughly estimated that the makeup water to a cooling tower would be 8 - 9 pounds per kWh generated. Even though I cautioned, I have had some poster's remorse.
So I drug (hillbilly for dragged) out my first edition Keenan and Keys, The thermodynamic Properties of Steam, and made a better estimate. To use some real numbers I used 600 psia 740 F super heated steam with 1 psia exhaust (@101.74 F) You are welcome to choose your conditions, but not valid for dual cycle or super critical - not likely in a hot desert anyway.) I have been trying to think of a power plant I have seen or oil refineries I have serviced that was not on a river or large body of water. I starter a catalytic cracker at Zarka, Hashimite Kingdom of Jordan. But this plant had no large turbines and did not generate electricity.
it was in Jordan that I first heard the joke about Moses wandering in the desert for.forty years only to pick out the only place in the area without oil.
Now I say 6.2 pounds of water per kWh generated in a Rankine cycle plant. A bodacious number in a hot desert. For a 200 meg plant that would mean 13,144/(8.33*60)=16,000 gpm. (I'd size the makeup line at 8 inches.)
My wife says nobody will read this post. Let's see.
Len Gould 4.11.10
Herschel: "trade off reliability of supply for more GHG released to the environment" -- of course, but still not near the amount released by pure fossil-fueled plants. It seems to me ingenuous to claim that 100% fossil-fueled electricity generation must be used because solar generation might also use small amounts (per Dessertec papers, 17%) fossil fueled generation.
So capital costs of the standby system are now the problem? I wouldn't expect that, since (last I heard) simple cycle turbine generating plants cost "in the range of" $600 / kw, whereas the solar generation is at now likely costing "in the range of" $4,500 / kw and dropping (eg. S&L / NREL's present-day $0.125 / kwh). I would expect that direct gas firing of the thermal fluid should cost significantly less than turbine generators if gas turbines with exhaust heat recovery are too costly.
Transmission of electricity (large amounts, HVDC, > 300 km) and Natural Gas are approx. comparably costly per kwh of electricity delivered at the destination, though its too bad we've made such large sunk investments in gas transmission. If you're planning to depend on shale gas resources into the distant future, you should get the delivery guarantees in writing, with penalty clauses. Some are quite sceptical, particularly regarding extremely rapid depletion rates of shale gas wells, apparently averaging only 1 or 2 years to uneconomic. Present market is likely an extreme anamoly. Last estimate I saw, ABB was ballparking 2 GW HVDC for 300 km at $325 million. So lets assume a 2 GW solar installation 325 km inland from LA, costing $7 billion capital + $1.4 billion in construction interest, to construct. The transmission will cost $1.06 billion. Given an 83% availability, with an average wholesale price of electricity at $0.07 / kwh, with 10% of capital per year in O&M, and an 8% interest payment on capital, 4.6% transmission losses, (and a whole lot of other quite reasonable assumptions), the system will retire its capital loans in 10.5 years. Of course we must then add the cost of pumping cooling water from either the ocean or some more useful location, but not likely significant.
Len Gould 4.12.10
Thanks Don: So what's the estimated cost to pump eg. 2x that requirement / MW, eg. 320,000 gpm (for 2 GW) of seawater inland for 225 miles when the destination is at sea level?
Don Hirschberg 4.12.10
Len, You seem to be searching for ways to make man's dilemma worse. Our problem is not C02, not peak or oil but peak almost everything. We 7 billion are in a life boat looking for a way to be rescued. I can figure ways to rescue 2 billion, not 7 billion, and still increasing at 80 million per year. All previous civilizations peaked at 0.3 billion or less, about 4% or less than present population..
Today 20,000 children died from diarrhea and tomorrow another 20,000 will die because they didn't put a few drops of bleach in their drinking water at a cost of mere cents. And you ask about the cost of pumping sea water hundreds of miles to a power plant not needed. it is an easy calculation, but how fatuous.
So what, when we are headed for a die-off that makes anything experienced in the past look like a mere walk in the park. Sorry, numbers have no conscience.
Len Gould 4.12.10
Don: How many in the interior of California or Arizona might be interested in fresh water
"The Republic of Trinidad and Tobago is using desalination to free up more of the island's water supply for drinking purposes. The desalination facility, opened in March 2003, is considered to be the first of its kind. It is the largest desalination facility in the Americas and will process 28.8 million gallons of water a day and sell water at the price of $2.67 per 1,000 gallons." Ionics to build $120M desalination plant in Trinidad - Boston Business Journal
Could an RO desalination facility be combined with cooling the condensers of a solar-thermal generating plant using seawater pumped inland, a very high brine concentration (RO desal plant --> solar thermal condensers stage 1 --> open pond w/agitators for evap cooling --> solar thermal condensers stage 2 --> salt production ponds) ?
Regarding your concern on population, the only ethical means at hand to address the problem is to improve the standard of living, education and personal freedoms of everyone in the world, so we'd all best get ourselves busy.
Too bad, but I guess it shows that water in the southwest US is clearly not close to being scarce yet.
Don Hirschberg 4.12.10
I have never been able to carry around water costs on the top of my head, perhaps because I have never seen them twice expressed in the same units, so without doing arithmetic I have no idea what is high and low. Len, in your last comment You used dollars per 1000 liters, which is .0..999973 cubic meters, but a cubic meter is exactly 1 stere. I presume m-3 means cubic meters or m^3? (and RO reverse osmosis?) I guess it is legal to use cubic meters in California and Arizona.so I am prepared to convert. Just yesterday I dealt with acre feet of water.and stream flow in thousand of cubic feet per second.
Despite the very low costs of agricultual water you cited the supply situation is marginal to desperate in many places. I understand that watering a lawn in Phoenix or Tucson is a capital offense, or ought to be.
Reverse osmosis is a desperate measure to supply drinking and sanitary water. I pay $ 0.85 / 1000 gallons for potable water delivered under pressure. The reverse osmosis figure you cite are $ 10.41 /1000 gal, over 12 times more costly but cheaper than distillation.
As for condensing turbine exhaust in the desert I can't conceive of a scheme that is both feasible and thermodynamically efficient. For thermal efficiency a very low pressure is required at the last stage (bladed wheel) of the turbine. We want almost zero pressure drop through the lines and condenser, even one psi drop hurts. All the "surface condensers" I've seen put the steam through the shell side and the cooling water through the tubes.
World Population. I believe we have already passed the point where our civilization can survive without a die-off, not merely of tens of millions as we experienced in the USSR and W.W.II and the Holocaust ,etc. but billions. As recently as about 1927 we could have at least in theory saved ourselves by zero population growth staring then, at 2 billion. Today we are 7 billion and growing. From the Dawn of Man unlit a thousand years ago world population had never been over 0.3 billion. Alas, ethics has nothing to do with it.
Don Hirschberg 4.13.10
As to education solving world problems. Absolute nonsense.
At he time of W.W.II the literacy rate in Japan was higher than the US. The Germans were the most sophisticated and literate in the world. Only Iowa had a better literacy rate than Japan.
Yet the almost unbelievable and sickening atrocities of the Japanese military against Koreans, Chinese, Filipinos, Americans (the Batton Death march one of the most egregious episodes in all history) has faded. Now they presume to lecture us on ethics.
Education. We have become dumber, far dumber. My grandchildren and later children know far less than I did at their age and get praised. They get A's. I got C's. . .
Len Gould 4.13.10
I can't really agree your last, my granddaughter in grade four is doing math we never did at that age, and also studying and becoming quite good at French as well as English. We didn't start studying French until grade 9.
Don Hirschberg 4.13.10
Len, I am pleased that your granddaughter is doing so well in school.. You must be very proud.
As to previous comments on California/Arizona water supply. I ran across a 2008 rating of cities as to the sustainablity of their water supply. At the tail of the list, that is,those most at risk were ten cities:. 4 in CA, 3 in AZ, one each in CO, NM an NV.
Michael Keller 4.19.10
At the risk of probably creating a small firestorm, India has an ambitious nuclear program, including using breeder reactors (several are running) and thorium - which they possess in abundance. I suspect, however, nuclear costs are ultimately somewhat less than solar, but the power can always be provided without regard to whether or not the sun is shinning and the fuel can be obtained from India.
As far as power plant cooling is concerned, there are power plants that use sea water mechanical-draft cooling towers. However, makes more sense to just use once-thru sea water cooling because it is more economical. Saltwater cooling towers also end up putting salt spray all over the area around the plant (drift from towers).
Combined-cycle power plants with air cooled condensers are a good fit for desert locations, provided there is access to natural gas. However, generally also need inlet air evaporative coolers for the gas turbines, so some water is needed. Inlet air coolers using chilled water from a refrigeration plant can also be used to reduce, but not eliminate, water use.
India might want to consider turning coal into substitute natural gas through coal gasification for use with combined-cycle plants and general use. However, mid-sized supercritical pulverized coal pants are undoubtedly the lowest cost solution, if coal is available. On the down side, my experience is that Indian coal is not very good. Circulating fluid bed boilers might be a better but more expensive solution (CFB's can burn pretty much anything).
As far as using solar with a combined-cycle plant (basically solar heat creates steam used with the plant’s steam turbine), the increased plant output is pretty small while the capital cost of the solar trough array (or tower) is pretty high. The economics are not very good and has only a limited ability to solve India's basic problem of not enough power.
If it were me, I would greatly accelerate the Indian nuclear program and use coal gasification to provide for the basic energy supply, while using some solar photovoltaic for villages with limited power needs and limited access to power lines. Ultimately, India needs to greatly expand the transmission and distribution system so power can be moved more easily throughout the country.
PS As far as using reverse osmosis (RO) in California for drinking water - the environmental lobby and mind-numbing, massive state bureaucracy continue to stymie that. Power plants, however, routinely use RO for water make-up to cooling towers.