The European Union will fail to hit its target to source 20% of its energy from renewable sources by 2020 unless the rate of investment in the industry increases sharply, according to a new report.

Figures produced by the consultancy Capgemini cast doubt on the EU’s commitment to its target.

The figures are particularly concerning at a time when European politicians are seeking tough carbon-cutting pledges from other leading economies at the Copenhagen climate summit in December.

Developing nations have suggested that they will sign up to a climate deal only if developed economies show they are making an effort to cut emissions.

But if the EU fails to hit renewable targets, it could hurt its negotiating position at Copenhagen.

In order for 20% of all the EU’s energy to come from renewable sources, about 33% of its electricity will have to be generated by wind, solar and hydroelectric – up from today’s 16% share, writes the Financial Times.

Although renewable energy has been growing fast, the rate of development has slowed significantly as investment has been hit by the recession.

According to Capgemini’s calculations only 8% of power generation capacity now under construction is for renewable sources, while half is for gas-fired and 24% coal-fired.

Overall global investment in clean energy is likely to be about $110bn (€74bn, £66bn) this year, down from $155bn last year, according to New Energy Finance, a research group, writes the Financial Times.