It would be wrong to multiply figures by four to estimate what might now have been in the U.S. because the contiguous 48 States have a much higher potential for all kinds of renewable energy. The legend of German wind maps ending where U.S. maps begin exemplifies the difference between becalmed Germany and the gusty coasts, shores, ridges, and plains of the U.S.

Conservative forecasts of future developments in Germany indicate that 35 percent renewable power is achievable by 2020, 50 percent by 2030, and 80 percent by 2050. These percentages would be achievable essentially without demand response or measures to stimulate demand flexibility. More ambitious but still entirely possible scenarios show that 100 percent renewable power can be reached by 2050, possibly even earlier if the shift to electric mobility accelerates and provides massive additional storage capacity to even out variations in power supply and demand.

The debate about the future of nuclear power in Germany appeared settled when in 1999 and 2000 the red-green federal government consisting of the Social Democratic and the Green parties negotiated a phase-out of nuclear power with the industry and upgraded the Stromeinspeisegesetz to become the Renewable Energy Act (Erneuerbare-Energien-Gesetz or EEG), the much-copied law providing priority access to the grid for power from renewable sources, and stable rate support.

Over the decades and layer by layer, technologies and the industrial base for a great energy transformation were built up, driven not only by misgivings about nuclear power but later also concern about climate change. Today, the positive vision is one of a smart power grid, with a mixture of large and small distributed renewable power plants, load-based tariffs stimulating demand response, and dynamically efficient feed-in from dispatchable generators and combined heat-and-power plants, with electricity stored in car batteries connected to the grid as well as in pump storage behind hydropower dams.

It is dawning on the German public that the co-transformation of the power and transport systems – where the large aggregate capacity of car batteries compensates for the predictable variations in wind power – will be easier and cheaper than separate reforms of each sector on its own. The price of electric cars made from light material is likely to come down even faster than that of solar panels, and within a few years could fall well below the cost of current cars based on oil and steel, which need high maintenance. Indeed, concerns are emerging that the new individual mobility with electric cars will be so much cheaper that the shrinkage of the after-sale service and maintenance industry, and the business closures and job losses to be expected, may happen quite quickly and might turn out politically difficult to manage. However, Germany is suffering from a skill shortage in a number of sectors and regions, so the economy as a whole would benefit from such a development, as it would free up highly skilled technicians that are be needed in other sectors, including renewable energy and the smart grid.