new delhi, Dec. 26 -- King Coal is tightening its grip as discoms flock to thermal power while cheaper green power waits for buyers, raising questions over India's ability to meet its energy transition goals. States such as Madhya Pradesh, Bihar, Assam and West Bengal have recently signed power purchase agreements (PPAs) for thermal power at tariffs as high as Rs.6.64 a unit, even though solar and wind power come for Rs.2.5-4. The key reason is the 'infirm' nature of renewable power - lack of generation when the sun doesn't shine, and the wind doesn't blow. Even those renewable projects with combined solar and wind generation, plus battery storage, are not finding takers despite being available at Rs.5 a unit or lower, as discoms remain wary of battery supply chains. Meanwhile, thermal provides the necessary base load. According to four people aware of the growing problem in India's green energy space, this signals a continued weakening in demand for renewable power in the days to come. "We are not sure about the viability of these proposed (green power) projects, with tariffs being quoted very low for standalone battery projects," an official at a state power distributor that has signed up for thermal power said. "Further, there is an 18% GST on battery services, which would increase the cost of power," the official said....