Cement companies in India have proposed investments of about $2 billion to ramp up their captive power generation base. The move is expected to reduce their expenses on power up to 30 per cent and ensure a reliable power-supply.Currently, the Indian cement industry has about 4,000 megawatt (mw) of installed captive generation capacity. With a host of greenfield and brownfield expansion projects in the pipeline, another 2,000 mw captive capacity addition is expected in the next three to four years in the sector.