They are asking for a legal instrument to provide investment protection against sudden subsidy cuts.
The commission's financial department is currently considering setting up an arbitration mechanism for resolving investment disputes at EU-level. This would replace bilateral investment protection treaties struck mainly between EU members and then candidate countries in central and eastern Europe in the 1990s.
An EU arbitration mechanism could be used by the renewables sector to seek compensation for the effects of retroactive subsidy changes. Such changes in several member states have undermined investor confidence and projects' viability, the industry said in a letter sent to the commission.
According to the letter, renewable energy investment in Europe has almost halved in the past four years, from $120 billion in 2011 to $65 billion in 2014.
In the absence of EU safeguards, renewables investors have to date taken legal action against subsidy changes at national level or through international arbitration, industry associations representing the main renewable energy sources said in a letter to the commission on Tuesday.
There are currently 15 cases pending against Spain's subsidy cuts under the international Energy Charter Treaty.
The commission is currently in talks with member states about a new climate governance framework to guarantee the achievement of the EU's 27% renewable energy target by 2030. EU leaders in October agreed that the target should be binding at EU level but not divided into national targets as is the case currently.