In energy storage, a key technology of the future energy system, Germany is making progress. Progress is also being made in heat pumps, heavy electric trucks, solar installations, and wind power, as shown by the new Energy Transition Monitor of the German Institute for Economic Research (DIW).
“Policy should use the favorable framework conditions instead of stepping on the brakes,” said the study author Wolf-Peter Schill, head of DIW’s Research Department “Transformation of the Energy Economy.” Federal Minister for Economic Affairs Katharina Reiche (CDU) is currently working on several proposed legal changes that could hamper the expansion of renewable energy.
Among the positive news, according to DIW, is the “dynamics of large-battery storage capacity.” It grew by 0.8 gigawatt-hours (GWh) in the second half of 2025. That means an increase of a little over 25 percent. Battery storage is important to secure temporary surpluses of renewable electricity for periods when solar and wind power plants produce little.
The growing battery capacity is likely to have contributed to a significant drop in the number of hours with negative wholesale prices in the second half of 2025. More storage thus helps to economically utilize the available electricity supply. However, storage capacities are still rising from a low base.
2.2 million heat pumps
Almost half of the newly installed heating systems in 2025 were electric heat pumps. In total, their number has reached 2.2 million units. This puts the DIW’s estimate of the future total number of heat pumps at 11.8 million, according to the researchers. Nearly one-fifth of residential buildings for which the technology is suitable are thus already equipped with heat pumps. This is assuming that, as part of the planned heat transition, more or less all currently fossil-fueled heating systems will be replaced.
In electric vehicles, DIW researchers Schill note particular progress in the segment of electric tractor-trailers. In the second half of 2025, 4.5 percent of new registrations were for these heavy e-trucks, compared with two percent in the first half. Schill attributes this to better battery technology and charging infrastructure. Nevertheless, the share of new electric vehicles among all new registrations remains low – for trucks overall 10.9 percent, for cars 20.4 percent, with a clearly rising trend.
Public support for the energy transition meanwhile declines, as the “Future Monitor of the Energy Transition 2026” from the Allensbach Institute for Demoscopy, commissioned by the BMW Foundation Herbert Quandt, revealed on Wednesday. Only a relative majority of 43 percent still regards the energy transition, with nuclear phase-out and the expansion of renewable energies, as the right path. The reasons for the shift, according to the institute, mainly lie in other topics becoming more important, such as economic stagnation and the Russian war.
