Two billion seeds stored at Kew's Millenium Seed Bank in West Sussex are to be kept cool by solar panels.
A total of 270 panels have been installed on the roof of the facility at Wakehurst Place in Ardingly, near Haywards Heath.
Tomorrow, the longest day of the year, they are expected to produce up to 400 kWh of electricity.
More top news
Here is the letter sent by the broadcasters to Prime Minister David Cameron's office in relation to the planned TV leaders debates.
A woman has avoided a jail sentence for possessing more than 600 indecent images - of children and pornographic images of animals.
Friday afternoon's forecast for the east of the region