Investments by the Clean Energy Finance Corporation, the $10 billion green investment bank under siege from the Abbott government, has reported an 45 per cent drop in annual commitments amid turmoil in the renewable energy industry.

The fund made commitments of $500 million in the year to June, down from $900 million in its first year of operations. The $1.4 billion total has also triggered a further $2.2 billion in investments from partners in those projects, saving 4.2 million tonnes of carbon dioxide emissions a year in the process, the fund said in a statement on Wednesday.

Stars are not aligned to ensure a stable policy environment for renewable energy. Credit:John Price

Oliver Yates, the CEFC's chief executive, told Fairfax Media that a dearth of opportunities across the industry was behind the fund's lower investments.

"There was a lot less investment in the renewables industry over the last 12 months than there has been in the last many, many years," Mr Yates said.