The joint study, conducted by Greenpeace and the Freiburg-based Öko-Institut, added that it could fall if industry exemptions were cut and taxes on electricity  favoured renewables.

The renewables surcharge will rise from €0.053 ($0.69)  per kWh to about €0.061 next year if the current pricing system continues, says Felix Matthes, who co-ordinates energy and climate policy at the Öko-Institut.

He adds that a recent push by environment minister Peter Altmaier and economics minister Philipp Rösler to cut feed-in tariffs (FITs) for renewables to avoid power price rises is misguided, as only some 7% of next year's surcharge will actually derive from FITs for new renewables plants.

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