Danish utility company Frederiksberg Forsyning is part of a vehicle-to-grid scheme.
Its all-electric vans charge up from the central grid, but at night the roles are reversed.
The vehicles’ batteries become an energy store that the grid can draw on to smooth out fluctuations in supply and demand.
This is part of the BBC’s Disruptors series. You can read the full article here.
Producer: Philippa Goodrich; Video editor: Sara Hegarty; Camera: Hans Schauerte