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.
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Thursday's weather for the west of the region
Thursday's forecast for the east of the region
Thursday morning's weather for the west of the region