Electric Bus Batteries Used to Store Solar Energy

The reuse and recycling of batteries is a key issue as increasing numbers of cities plan transition to electrically powered transport. Volvo Buses is taking part in a research project whereby used electric bus batteries get a second lease of life as solar energy storage units.

The research is taking place in Riksbyggen’s Viva housing cooperative in Gothenburg, an apartment complex that aims to be Sweden’s most innovative and sustainable housing project – Positive Footprint Housing. Tenants are just starting to move into their new apartments.

In Viva housing cooperative, Riksbyggen, Volvo, Göteborg Energi and Johanneberg Science Park have created a unique system whereby energy from solar panels on the roofs of the apartment buildings is stored in batteries that previously powered electric buses on route 55.

The energy warehouse is used to cut the property’s power consumption peaks, and to store or sell surplus solar energy. It can also be used to buy and store electricity from the national grid when it is cheap and green, for later use. This improves the efficiency of housing association Viva’s own energy system as well as that of the city’s power grid.

The battery warehouse consists of 14 used lithium-ion electric bus batteries. They are installed in a battery chamber and linked together to create a 200 kWh storage pack. This energy warehouse allows a larger proportion of Viva’s solar-generated electricity to be used for the housing association’s power needs.

The research of energy storage in used bus batteries is done with support from the EU project IRIS Smart Cities. IRIS is a Light House project, financed by EU HORIZON 2020.