Germany must speed up the renovation of its building sector to achieve the federal government’s climate-neutral target by 2045. Prefabricated, decentralised and modular renewable energy (RE) units fitted into the façades of buildings offer one solution. The Fraunhofer Institute for Building Physics (IBP) and the Fraunhofer Institute for Energy Economics and Energy System Technology (IEE) have joined forces to develop the solution.

The focus initially is on offices, schools and administration buildings built between 1950 and 1990 that used a typical frame construction method where reinforced concrete columns were used in place of load-bearing walls. During the renovation, the old façade elements are removed and new floor-to-ceiling modules are fitted. Each unit (approximately1.25 m wide and 30 cm deep) can supply heat and cooling to an adjoining room up to 24 sqm. The solution can be implemented in a few hours and plugged in to work straight away, independent of the building’s interior infrastructure and pipework.

“We are not renovating the entire building, just the facade,” explains Jan Kaiser, project manager at Fraunhofer IEE in a press release. The RE module forms an energy envelope: PV modules power an integrated, intelligent heat pump which then generates and regulates heating and cooling inside. From each unit of electricity, the pump can produce three to four units of heat.

The energy savings potential is considerable. It’s estimated that frame construction style office buildings consume 3,200 GWh of electricity each year. The RE modular facade would reduce this to 600 GWh, while the high level of prefabrication would reduce the need for a complete energy renovation.

The initiative is supported by the Federal Ministry for Economic Affairs and Climate Action and harnesses the expertise of various technology partners.