The power cuts in northern and eastern India this week will have presented citizens with a situation very familiar to Indian cement producers. With over half the country reported to be without electrical power after three power grids collapsed, industrial users are likely to have been shut down as the authorities try to bring back domestic supplies.

According to figures from the National Council for Cement and Building Materials, Indian cement producers used 79kWh/t of electrical energy in 2009 as production hit 181Mt. The Cement Manufacturers' Association placed these figures at 68-93kWh/t for a modern plant and 100-120kWh/t for older ones. In June 2012 the Central Electrical Authority reported the country's entire installed electrical capacity was 205GW.

It's difficult to estimate how much damage problems in power supply may have caused the Indian cement industry over the last few decades in either reduced volumes or increased running costs. The Cement Sustainability Initiative and European Cement Research Academy broke down the share of electrical power in a dry process plant as follows: 38% for cement grinding, 24% for raw material grinding, 22% for clinker production including grinding of solid fuels, 6% for raw material homogenisation, 5% for raw material extraction and blending and 5% for conveying, packing and loading. Generally speaking, interruption of power causes production losses and low capacity utilisation, idle running of equipment during stops and restarts of the plant, thermal losses during reheating, damage to refractory and other problems such as slowing down the train network.

Subsequently there has been a drive in India towards captive power generation and waste heat recovery (WHR) mechanisms, especially as input energy costs have risen. For example it has been reported that ACC's average cost of electricity per kWh from its captive plants is US$0.067 versus US$0.087 for grid power. Companies like Shree Cement have since gone into the electricity export market with their surpluses and, as shown by SP Ganeshan at the Global CemPower Conference in June 2012, interest in WHR is booming. Currently, the Indian cement industry has about 4000MW of installed captive generation capacity, including coal-based plants, diesel generating sets and wind turbines. Through various greenfield and brownfield expansion projects it is anticipated that another 2000MW of captive capacity will be added by 2016.

One sign of how well the Indian cement industry is coping with its energy requirements is the 74% rise in fourth quarter profit reported by Shree Cement in May 2012, in part due to savings made from captive power generation. Perhaps they could advise the Indian electricity board.