Carlyle Group is targeting at least $1.6 billion for a second private equity fund which will focus on investments in renewable energy and sustainability assets, according to a report by Reuters.

The report cutes sources familiar with the matter as saying that Carlye began raising capital for Carlyle Renewable & Sustainable Energy Fund II earlier this year, which it achieves its target size, will be twice the size of its $800 million predecessor fund.

Carlyle has already been active in renewable energy and sustainability sector investments this year, investing $350 million to acquire a majority stake in US renewable energy developer Aspen Power Partners in November as well as launching Telis Energy which will target clean energy projects in Europe.

Read more: Private Equity Wire