Solar power plants' output high, but varying widely

Last Updated: Wed, Jan 02, 2013 20:54 hrs

The ministry of new and renewable energy (MNRE) recently released data of power generation from solar plants constructed under the Jawaharlal Nehru National Solar Mission (JNNSM) for November. And the results span from very good to dismal.

November means short days for the solar plants, but according to Vineet Mittal, managing director of Welspun Energy, a solar power developer: “November is one of the better months with no rain or dust and with lower temperatures, closer to the conditions they are made for, increasing output from the cells.” Efficiency of solar power plants is measured by the capacity utilisation factor (CUF), that is, how much of the stated capacity a plant actually generates compared to its total possible capacity in a laboratory with constant light. The higher the CUF, the more efficient the plant is at producing energy from the Sun. Due to weather and the unmissable fact that the sun is only available half the day, a 5 MW plant is expected to generate about 1 MW of electricity per hour on an average.

The central electricity regulatory commission (CERC) has set 19 per cent CUF as the norm. Of the 30 planned 5 MW photovoltaic (PV) solar power projects in the first batch of the solar mission, only 21 plants are reporting any production—a few of the plants were cancelled at bidding or due to delays—but about 20 MW of capacity is still missing from production figures. The producing plants have an average CUF of 19.48 per cent. All but four of the reportedly generating plants are situated in Rajasthan.

Northwest Energy's 5 MW project in Rawra village in Jaisalmer district has the best figures for managing CUF of 23.60 per cent in November with an output of 839 MWh of clean power. That is enough to provide power to about 12,500 people. While most solar power projects have been built in Rajasthan, one project doing well is Welspun Energy’s 5 MW plant in Thummala village in Anantapur district of Andhra Pradesh with a CUF of 21.71 per cent with an output of 771 MWh, which is enough for 11,500 people. Mittal said, “High generation comes from investing in talent, finding the right location through radiation data and using the right solar modules for the right area. The same technology may not be optimal in all parts of the country.”

On why Welspun Energy opted for Andhra Pradesh while most projects under JNNSM have been set up in Rajasthan, he said: “We wanted to explore more arid zones of the country and our plant generating as much as those in the northwest of the country shows that other states are feasible.”

The worst performing 5 Mw projects (among the ones producing any noticeable output) is EMC Limited in Uttar Pradesh. with a CUF of 14.97 per cent.

Reprinted with permission from Down to Earth magazine

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