One of the UK’s largest installations of photo-voltaic cells on a historic building has been fitted to the roof of the National Trust’s carriage museum at Arlington Court near Barnstaple in Devon.

The installation will generate up to 6.3 megawatt hours of energy each year, saving the museum about £600 on its electricity bill and generating income of around £2,270 per year by feeding electricity back into the grid under the Feed-in-Tariff.

The project has been funded by sales of National Trust Green Energy, which is supplied by the charity’s energy partner npower and raises money to support low and zero carbon energy savings projects at Trust properties.

So far, 25 National Trust properties have benefited from the partnership, with solar panels, biomass boilers and ground source heat pumps helping generate energy and save money on fuel bills. The Trust wants to cut its overall energy demand by 20% by 2020 and to switch to renewable energy.

The installation will also help protect the historic carriages in the museum, with the cells helping to reduce the amount of ultraviolet light that enters the building.

Arlington Court property manager Ana Chylak said: “The project involved replacing 88 panes of glass with laminates which incorporate 27 PV cells in each unit, spaced to allow 30% light transmission.

“We have worked hard across the property to reduce our energy consumption and it has already really made a difference to our bills. With these panels we can make a small contribution to the power we use as well as protecting our amazing carriages.”

The completion of the work comes at the same time as the Trust and npower announced the extension of their partnership for another two years.