The four specialists supervising Germany's planned transition to renewable energy have said the government will fail to meet crucial targets for energy efficiency if the pace of improvements is not accelerated.
For instance, the aim to lower the primary energy consumption by 20 percent on 2008 values by 2020, energy efficiency must be raised by 2.6 percent every year - at the moment, that figure is just 1.6 percent.
The commission wants to see special efforts being made in improving energy efficiency in buildings, which use up 40 percent of the energy supply. Transport is another area of concern, the report said.
Researchers say that the cheapest option for increasing the capacity for renewable energy is building more wind parks on land - but they need to be better coordinated with the national grid.
"The individual German states have some very ambitious construction targets for wind energy, which taken together significantly beat the federal government targets," the report said.
The commission is chaired by Andreas L?schel of the Centre for European Economic Research (ZEW) in Mannheim, and is occupied by Georg Erdmann of the Technical University Berlin, Frithjof Stai?, from the Centre for Solar Energy and Hydrogen Research Baden-W?rttemberg (ZSW), and Hans-Joachim Ziesing, of the Working Group on Energy Balances (AGEB).
The commission also said media reports of rising electricity costs were exaggerated, and called for a more reasoned debate on the energy issue.