The company said energy generated by the onsite solar array will power the store and charge up batteries which will then power the store during the evenings. Meanwhile, a new air source heat pump, coupled with a range of efficiency measures, has allowed the firm to replace gas and electric heating units. "Surplus power goes back to the grid, off-setting the days in winter when the solar PV will be generating less power and grid energy is needed to power the store," Kingfisher said.