Tuesday, July 31, 2012

Change power generation configuration to stabilise the grid
Chandra Bhushan
Two consecutive days of grid collapse has left almost half of India’s population without power. Three major grids – northern, north-eastern and eastern – have crashed. Reportedly, over 20 states have been affected. Trains have stalled, markets have closed down, and institutions and offices have been forced to announce holidays. In short, this is nothing short of a national calamity.
What are the reasons behind this massive grid failure?
The simplest is that states have withdrawn more power than they are entitled to, thereby tripping the grid. As the peak load deficit is about 15,000 MW, without grid discipline, such failures are bound to happen. Most states do not have any system in place that can stop them from withdrawing more power from the grid than what is allocated.
But there is another fundamental reason that we are not addressing. More than 80 per cent of the power generated in the country comes from thermal power plants – coal, lignite and gas-based. Another 3 per cent is from nuclear power plants, hydropower plants produce about 12-13 per cent (including imports from Bhutan), and the remaining 2-3 per cent is from renewable sources – mostly wind and solar.
We therefore rely largely on base load power plants – thermal, nuclear and even some hydropower plants operate at base loads -- to meet our electricity needs. We have very little flexibility on peak load power plants. So when the peak demand surges, we have no source to supply electricity to the grid.
With a drought looming large and no sign of monsoons, millions of air conditioners keep humming in our cities while farmers have begun using more power to pump out groundwater for irrigation. The result: higher demand and low supply even during non-peak periods.
Electricity generation for the month of June illustrates this problem:
§ In June 2012, India produced 8 per cent more electricity than in June 2011.
§ The generation from thermal power plants was 11.4 per cent higher than in June 2011. Coal-based power plants generated 16.7 per cent more electricity.
§ However, with low monsoon, the generation of electricity from hydropower plants reduced by 6 per cent compared to June 2011. In fact, hydropower plants produced 19 per cent lesser electricity in April-June, 2012 than the corresponding months in 2011. As hydro plants are also peak load plants, this reduction seems to have affected the peak power generation in the country significantly.
Apart from grid discipline and setting up systems that ensure that states do not overdraw power, we will have to change our electricity generation configuration for the stability of the grid. In this context, large-scale installation of renewable energy plants like wind and solar plants will play a major role in stabilising the grid, as their power generation profile -- especially that of solar -- matches the peak demand in the country.
Chandra Bhushan is deputy director general of Centre for Science and Environment (CSE), New Delhi. He can be reached at chandra@cseindia.org.

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