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India Unveils the World's Largest Solar Power Plant (aljazeera.com)
Kamuthi in Tamil Nadu, India is now home to the world's largest solar plant that adds 648 MW to the country's generating capacity. Previously, the Topaz Solar Farm in California, which was completed two years ago and has a capacity of 550 MW, held the title. Aljazeera reports: The solar plant, built in an impressive eight months, is cleaned every day by a robotic system, charged by its own solar panels. At full capacity, it is estimated to produce enough electricity to power about 150,000 homes. The project is comprised of 2.5 million individual solar modules, and cost $679 million to build. The new plant has helped nudge India's total installed solar capacity across the 10 GW mark, according to a statement by research firm Bridge to India, joining only a handful of countries that can make this claim. As solar power increases, India is expected to become the world's third-biggest solar market from next year onwards, after China and the U.S.
Let's see, 648K kwh * $.08 per kwh * 8 hours in a day * 365 days in a year = $151M per year. So it pays for itself in under 5 years. Yup, not bad.
It is not a bargain at all. Also that price is construction only, and fails to include all owner's costs in development, not to mention the capacity factor is far below conventional power plants.
Well yeah, it's a PV Solar plant of course it has a lower capacity factor than a conventional plant, you might as well just say "It's dark at night"
But given this is India, expecting them to build a modern combined cycle plant without natural gas infrastructure, or nuclear power without experience is too much.
You mean like the Sugen combined-cycle power plant in Gujarat, India? Or one of the 22 nuclear reactors in operation at seven sites that generate about 25% of India's electricity?
I don't want to belittle this because India is one of the places where solar actually makes sense. But even there its capacity factor is only about 20%. Compared to 14.5% for the continental U.S. and about 10% in Germany. Capacity factor is the ratio of actual electricity produced (after taking into account night, weather, angle of the sun, downtime due to maintenance, etc) to nameplate (maximum) capacity.
So while it's capacity is 648 MW, its average electrical generation over a year will only be about 20% that, or a more modest 130 MW. Electricity costs about 8 cents/kWh in India. So payback time (excluding operational expenses and interest on loans) will be
($679 million) / (0.2 * 648 MW * 3600 sec/hour * 8766 hours/year * $0.08/kWh) = 7.47 years
India is one of the better places for solar. (The 150,000 home figure seems a little screwy, since 648 MW / 150,000 homes = 4320 Watts, which is about 3.5x the electricity consumption of the average U.S. home. I suspect the 150,000 homes figure already took into account capacity factor, and is not "at full capacity" as TFA claims.)
Well, the estimate assumed 8 hours a day, so 4 hours either side of noon. Assuming that power varies as the cosine of the angle, averaging between -/+ 60 degrees gives sqrt(3)/(2*pi/3)=82.7% of peak.
Averaging over -/+ 90 degrees (i.e. 12 hours) gives 63.7% of peak, i.e. the equivalent of 7.6 hours of peak output per day. So the 8 hr/day figure seems a reasonable ballpark estimate.
Doesn't account for latitude, season or weather, YMMV, contents may have settled during transit, etc.
648 MW ... .0007% of India's electricity consumption, based upon 2011 figures... at that rate, they'd need to cover a fifth of the country with PV panels, never mind night time load.
That's a hell of a lot of land for
Your numbers are way off.
648MW / .0007% = 92 TW
All of human civilization consumes about 500 exajoules of energy per year, which is only about 16 TW. (Of which electricity is only a fraction, BTW)
Covering 1/5 of India with solar panels would actually potentially generate enough energy to power the entire planet several times over.
I recall hearing a calculation on the radio: if we keep expanding our energy use at the present rate, in 2000 years, we will need more energy than all the stars in our galaxy produce.
True, but we won't be around to see it, because of the black hole that will be created by the mass of all of the disco records we'll have produced by then.
I don't care if it's 90,000 hectares. That lake was not my doing.
His math works out, averaged over a year:
500e18 J/(356*24*3600 s) = 15.85e12 W
I'm all for exploring alternative forms of generating electricity. The continued investment in these technologies will be very helpful in building a future that generates more power with less pollution. I also think that it is useful to look at these numbers in context. The state of Tamil Nadu generates around 23,000 MW of electricity using many types of fuels and technologies. Coal fired power plants account for about 10,000 MW making it the single largest source of power for the state. This is similar to many developing areas. What is impressive is that they are able to use so many different means of producing power. Hydro electric in Tamil Nadu is 2,200 MW, Nuclear is 1,000 MW, and 'other renewable' a hefty 8,000 MW. In comparison the Three Gorges Dam, located in China has a capacity of 22,500 MW. It is the largest power station in the world, also the largest construction project ever.
Your calculation is a just bit too simple and optimistic.
Madurai (about 50km away from the power plant) has an average global horizontal irradiance of 224W/m**2.
At 9 degree latitude North, the optimum tilt angle is pretty close to horizontal : 10 degree tilt only brings 2% more irradiance over the year
Total insolation is year * average irradiance ~ 1960kWh
The performance ratio of such a power plant could be around 85%, with cable losses, inverter losses and automated cleaning.
The nominal power of the installation is 648MWp, tested under an irradiance of 1000W/m**2.
So your expected yield is :
1960kWh/(m**2*year)*85%*648MW/(1000W/m**2) ~ 1.1 TWh/year
compared to your result of 1.9 TWh/year.
The plant should pay for itself in less than 8 years, and your calculation wasn't too far off.