Foreign investment in India's renewable energy sector has picked up speed in the last four years, with investors including Japanese firms laying down big bets on the country's green energy push.

According to government data, foreign direct investment in the sector has totaled $3.8 billion over the last four years, accounting for around 56 percent of the $6.84 billion poured in during the last 18 years.

The government has taken various steps to attract investment from both within the country and overseas, including fiscal and promotional incentives.