"It is important that we remain competitive in comparison with other countries. If not, a company of global stature like Bayer can think about moving its production to countries where energy costs are lower," he said.

Offshore wind parks are often hailed as the future of renewable energy in Germany. But they actually lag far behind their terrestrial counterparts. ...Meanwhile dissent is growing amongst citizen groups who dislike the presence of turbines on their doorsteps.

Germany plans to exempt 1,550 large firms from a power price surcharge that covers part of the cost of switching to renewable energy. Critics say the list of exemptions is spurious and unfair to households and small businesses. It risks undermining faith in the government's switch to clean power.

Like solar, wind generation varies greatly depending on weather conditions. Power prices have dropped to negative values already at times of extreme wind supply and low demand. ..."If Germany adds 5 GW of solar this year, we may end up with over 50 GW of volatile wind and solar capacity that can't be controlled according to demand."

High wind-power production in Germany one Saturday night helped extend a blackout across Europe. Last month, the Conservative government joined the long line of governments around the world subsidizing the production of wind power. Meanwhile, new information about wind power from Europe raises the spectre of unexpected blackout risks, high costs, unreliable production and even questionable environmental benefits. Concerns over wind power used to focus on whether enough wind would blow to keep wind generators busy and electric power grids supplied. Now, after a major power blackout in Europe in November that left 15 million households in the dark, concerns over wind power come from an entirely opposite direction – fear that wind power can unpredictably produce more power than a system can handle.

Fresh concerns have emerged over the future of BP's alternative energy business after a fire broke out at one of the company's largest solar power installations in Germany. The incident on June 21 destroyed nearly 200 sq m of one of the world's largest roof-mounted solar panel arrays on a warehouse complex in Bürstadt, near Mannheim.

In an interview with German weekly newspaper Die Zeit, Altmaier said “with 35 percent of power from renewable sources, that still leaves 65 percent to be covered. It makes sense to replace old brown and black coal-fired plants which aren't good for the environment with modern and efficient coal and gas-fired power plants.”