The Queen gave a surreptitiously royal nod to sustainability when she officially opened a history centre powered by biomass.

Accompanied by Prince Philip, Her Majesty perused the display at the Keep which houses archives up to 900 years old. It is sited next to the University of Sussex in the south coast of England.

The modern building – despite its medieval name – is heated by a 300 kilowatt biomass boiler installed by Rural Energy.

The boiler is fuelled by woodchip and generates heat and hot water for the centre, which is set to welcome around 16,000 visitors a year.

It is one of several ‘green’ schemes begun by the university including installing solar panels and reusing rainwater.

The Keep is home to six miles of archives which document the lives of individuals, places and events, including written records, maps, plans, films, photographs, prints and drawings.