It marks a major shift for the firm, which produces most of India’s coal.
“Coal as you know, we’re going to lose business in the next two, three decades. Solar will take over (from) coal slowly as a major energy provider in the coming years,” CIL’s chairman Pramod Agarwal said in an interview with Reuters.
The company’s solar project with NLC India will be worth 125bn rupees ($1.73bn ; £1.26bn), with CIL expected to invest roughly half of that figure by 2024.
The group closed 82 mines in the three years to March 2020, and reduced its workforce by 18,600 employees.
Mr Agarwal said he expected further reductions to the workforce, with the savings potentially reinvested into solar wafer production.
Energy transformation
India currently uses about one billion tons of coal annually, making it the world's second largest consumer behind China.