India may build new coal-fired power plants because they generate the cheapest power, according to a draft electricity policy document, despite growing calls from environmentalists to deter the use of coal.

Coal's contribution to electricity generation in India fell for the second straight year in 2020, marking a departure from decades of growth in coal-fired power. Still, the fuel accounts for nearly three-quarters of India's annual power output.

Environmental activists have long rallied against India adding new coal-fired capacity. Solar and wind energy prices are falling to record lows, which would help the world's third-largest greenhouse gas emitter cut emissions.