The National Marine Aquarium in Plymouth will soon start turning solar energy into electricity.
The National Marine Aquarium is the UK's largest aquarium exhibition
The aquarium is one of 18 buildings in the country - including the Eden Project in Cornwall - to share £2m of government money to fit solar panels.
The solar panels will be fitted into the existing roof lights of the aquarium building at a cost of £117,000.
All the projects will have a combined output to meet the electricity needs of 140 homes.
The National Marine Aquarium is the UK's largest aquarium exhibition area and houses Europe's deepest tank.
Energy from the sun can be harnessed in solar cells - also called photo-voltaic cells
For: Rapidly coming down in price, cell technology means even moonlight may be harnessed in the future
Against: Expensive to harness, intermittent source of energy
The solar system in the aquarium's moorland stream exhibit hall will reduce the energy required for cooling the exhibit.
The Eden Project, near St Austell in Cornwall is also in line for £300,000 to provide solar heating for its planned new education centre.
Energy minister Brian Wilson said: "The Energy White Paper delivered clear aims for renewable energy, to achieve our ambition of doubling the share of renewable electricity by 2020 from our 2010 target of 10%.
"These projects will help us achieve that goal, they demonstrate that renewable energy sources can be used in any building from houses to aquariums, anywhere in the country."