A three-year study of Germany’s energystoragemarket funded by the government is not likely to favor batteries.

Although the full conclusions won’t be published for a while, a study supported by the Federal Ministry for Economic Affairs and Energy has found that grid-scale and behind-the-meter batteries are insufficient to meet Germany’s energy needs.

That’s according to Christoph Pellinger, the coordinator for the study, called Merit Order for Energy Storage Systems 2030.

Instead, residential and industrial power-to-heat systems, along with demand-side management of industrial and residential energy consumption, are the country’s best options to manage large amounts of renewable energy on the German grid, said Pellinger. The report will also favor vehicle-to-grid technologies as an economic grid-balancing option by 2030.

The study looked at the role of different storage systems on the grid and assessed what system infrastructure would be needed to ensure a reliable energy supply in the next decade and a half. The analysts assume that adoption of renewable energy will continue as part of Germany’s commitment to its energy transition policy, called Energiewende. In fact, they think that projections for renewables in Germany’s generation mix are on the conservative side -- predicting that renewables will account for 60 percent of energy in 2025 and 85 percent in 2035.

An executive summary from the study is due to be published late this month or early next. Pellinger said the study will emphasize the potential for power-to-heat and demand response as the best ways to manage the grid. However, he concedes that regulatory reforms will be needed in order to give them the opportunity to grow.

The report will likely play down the importance of battery storage.

“I can think of lithium-ion battery storage for primary frequency control; however, the market is rather small, with less than 600 megawatts in Germany and 3,000 megawatts in Europe. So far we do not see batteries on the grid scale for load-shifting purposes in Germany,” said Pellinger.

He is also cautious about the role of residential storage. “Batteries for residential storage might have an impact, but they are even less economically viable than most analysts think. Home storage units often consume a surprising amount of electricity themselves in standby mode, and this is rarely taken into account,” he said, citing a figure of between 20 and 70 watts, published in a recent German-language article.

However, these conclusions are not without their critics.

“It’s notoriously difficult to make predictions in this field, as the technology and prices are changing so rapidly,” said Philip Hiersemenzel, a spokesperson for the German energy storage company Younicos.

Professor Volker Quaschning of the Berlin University of Applied Sciences said he actually foresees a “strong role” for batteries at the grid level. And despite some current problems, he believes the residential storage industry is seeing prices fall at a promising rate.

Hiersemenzel criticized the emphasis on power-to-heat systems, saying that the researchers were giving too much credit to “old solutions” with little room for economic improvement.

Quaschning agreed with Pellinger’s assertion that a large fleet of electric vehicles could be useful for storing cheap excess energy. However, he stressed that the 3 million to 4 million EVs needed on Germany’s roads to enable meaningful vehicle-to-grid storage are not a given, even by 2030.

Hiersemenzel also has his doubts about using EVs to help balance the German grid. “The investigation has certainly asked the right questions -- but whether it has provided the correct answers remains to be seen,” he said.