Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) has committed to expanding its research and development activities in a range of technologies considered “complementary” to solar as key foundations of a transformation to distributed, low emissions energy networks.

Fraunhofer ISE has opened a new centre in Auerstrasse in the institute’s home city of Freiburg, Germany. Work carried out there will focus on energy storage battery R&D, on producing hydrogen from renewables, solar thermal storage and heating and cooling building using heat pumps. The new facility will allow the institute to “significantly expand its laboratory equipment”, a statement read, with the institute describing storage and heat as "important pillars of the energy transition".

The technical labs focusing on energy storage will research different types of batteries including flow batteries, while looking into a number of different applications for them, including PV and mobility. One particular aspect of this will be a facility to rigorously test battery cell and system behaviour under different temperatures using a calorimeter. Examining the behaviour of batteries while they are in use has been a challenge for R&D professionals and scientists, with a number of novel approaches attempted. Fraunhofer ISE says its team will use algorithms based on parameters including voltage and temperature to calculate the state of a battery as it works. The institute hopes that when it comes to looking at vehicle batteries, it will give a better impression of how battery cells or systems might behave in the field.

Additionally, Fraunhofer has recently stepped up its activities in hydrogen electrolysis. The new centre in Auerstrasse will include a laboratory for megawatt-range electrolysers, specifically chosen for their usefulness in turning variable renewable energy resources into grid-friendly power. Fraunhofer uses rapid-responding polymer electrolyte membrane (PEM) based electrolysers, which it claims can operate at twice its nominal power for as long as 15 minutes. In other words, a one megawatt system could be used to convert two megawatts of surplus power into hydrogen, at 75% efficiency.  

At a conference in Dusseldorf in March this year, speakers including Fraunhofer ISE’s chief, Prof Eicke Weber, said that for very high penetrations of PV and wind power onto grid networks, hydrogen and other so-called ‘power-to-x’ technologies would be among the most efficient long term options.

“With such systems in the grid, the problems associated with the planned grid expansion become less urgent,” the institute’s statement yesterday said.

Dr Christopher Hebling, director of hydrogen technology research at Fraunhofer explained that around 1% of Germany’s annual electricity production is wasted due to curtailment of wind facilities due to the grid being overloaded.

“In spite of this, the wind park operators are still reimbursed for the disposed energy and the costs are added onto the electricity price. By placing PEM electrolysers at the overloaded grid nodes, however, the grid operators can start within seconds to produce energyrich hydrogen from surplus wind or solar power, which would otherwise be disposed of. The produced hydrogen can be either used directly for fuel cell vehicles or be converted with carbon dioxide into fluid fuels or basic chemicals (Power-to-Liquid),” Hebling said.

In an interview with PV Tech’s sister site PV Tech Storage earlier this year, Hebling said that while hydrogen was not perfect for all applications, its advantages included the fact that hydrogen-fuelled cars could have a range of hundreds of miles, comparing favourably with existing battery-based electric vehicles (EVs). Japan in particular has seen several of its major automotive manufacturers bring out hydrogen cars.

The other areas researched at the Auerstrasse centre include solar thermal technology for solar power plants, where heat transfer media such as molten salt can be used to draw off energy away from solar radiation and then storing it at high temperatures to later generate electricity from using turbines. Finally, the new research centre includes heat pump technology, with Fraunhofer pointing out that 40% of energy consumed in Germany goes toward heating and cooling buildings, with much of western Europe thought to be in similar circumstances. 

Fraunhofer ISE has played a prominent role in Germany’s Energiewende (“energy transition”) over the years. Prof Eicke Weber writes a newspaper column and recently announced that he is going into regional politics