Power generated from a scenic lake is set to heat one of the country's grandest stately homes.

Blickling Hall's precious book collection and array of wildlife will benefit from the new green energy system.

Three miles of pipes have been connected in a giant underwater loop to the largest lake source heat pump in use by the National Trust.

The pump pushes glycol through the pipe network, which absorbs heat from the surrounding lake water. The temperature is then raised by an electric compressor and removed through a heat exchanger, to harness constant heat and continuously re-use the liquid glycol.

It is so efficient, that for every 1Kw of energy required, 4-5Kw of equivalent heat energy is produced.

The hall, near Aylsham, used to be heated using traditional oil fired boilers. The lake source heat pump uses a little more electricity to drive the pump, but will save the National Trust over £30,000 a year on oil costs.

It will also reduce carbon emissions by 69 tonnes a year and as part of the National Trust's Renewable Energy Investment Programme it will help contribute to an ambitious target of transferring 50pc of its usage over to renewables by 2020.

Spike Malin, Blickling's premises manager said: 'It was an easy decision to make; not only will it reduce our carbon footprint and save money that can be put towards conservation projects here at Blickling, it's safer for our wildlife too.'

Teaming with wildlife and measuring 2km at its widest point, Blickling's lake supports a diverse ecosystem including carp, pike, reed warblers and great crested grebes.

But it's not just the living creatures that will benefit. The precious collection housed at Blickling will be given a longer lease of life too.

The library at the Jacobean hall has one of the most significant book collections in the National Trust. With over 12,500 volumes in the collection, including editions of Jane Austen's Pride and Prejudice and two rare copies of the Coverdale Bible, the first English language bible.

Kenny Gray, Blickling's house steward, said: 'The delicate nature of our books means a constant ambient temperature is essential for prolonging their life and slowing down the rate of deterioration. The oil fired boilers that we were using tended to result in temperatures fluctuating; encouraging mould, pests and cracking along the spines of the books.'