A draft final statement at a European Union summit on Friday set a binding target of 20% of renewable sources in EU energy consumption by 2020 but offered flexibility on how member states meet that goal.
The compromise circulated by EU president Germany on the final morning of a two-day meeting said "differentiated national overall targets" for renewables should be derived "with due regard to a fair and adequate allocation taking account of different national starting points".
The wording appeared aimed to win over states reliant on nuclear energy, such as France and the Czech Republic, or coal, such as Poland, by adding references to the national energy mix.
German Chancellor Angela Merkel was hoping to clinch a deal on a long-term strategy integrating energy and climate change to pressure the United States and other industrialised and emerging nations to follow the EU lead in combating global warming.
On Thursday, the 27 leaders committed themselves to an ambitious target of reducing EU greenhouse gas emissions, blamed for heating the planet, by 20% by 2020 and offered to go to 30% if other nations follow suit.
The draft statement, seen by Reuters, also set a 10% minimum target for biofuels in transport to be introduced by 2020 in a cost-efficient way.
In an attempt to balance pro- and anti-nuclear states, the draft added wording on the contribution of nuclear energy "in meeting growing concerns about safety of energy supply and CO2 emissions reductions while ensuring that nuclear safety and security are paramount in the decision-making process".
Leaders came close to a deal on renewables on Thursday but several countries sought assurances that their special circumstances and financial limits would be taken into account when sharing the burden of meeting an EU-wide target.