Plas Newydd mansion powered by sea energy

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We’ve sailed through a good energy milestone after completing Britain’s biggest marine source heat pump, which will warm up a 300-year-old mansion on the North Wales coast.

This project at Plas Newydd is the first of five schemes to be completed in a £3.5 million pilot phase of our Renewable Energy Investment Programme, which was launched last year in partnership with our partner Good Energy.

Swapping oil fuel for sea energy

The marine source heat pump will provide 100 per cent of the heating needed by Plas Newydd Country House and Gardens in Anglesey. The 18th-century mansion used to be our biggest oil user and on some winter days would consume 1,500 litres of oil a day – the same as a typical house would use in ten months.

Now Plas Newydd will be heated with a new local and clean energy system, which pumps a small amount of sea water from the Menai Strait in Anglesey, through pipes to and from a heat exchanger on the shore, and then up 30 metres of cliff face to the mansion’s boiler house.

The 300kW marine source heat pump – one of the first and the biggest in the UK – cost £600k to install in total and is expected to save us around £40,000 a year in operating costs. That money can be reinvested back into the conservation of this elegant mansion, from its military uniform collection to a cricket pavilion on the estate.

Challenges and champions

Adam Ellis-Jones, our assistant director for operations in Wales, said: 'With the Irish Sea right on the doorstep of Plas Newydd, a marine source heat pump is the best option for us.

'However, being a pioneer is never easy. There are very few marine source heat pumps and none of this size in the UK, so it has been a challenging project but a very exciting one.

'From the start, we’ve worked closely with SEACAMS (Sustainable Expansion of the Applied Coastal and Marine Sectors), led by the School of Ocean Sciences at Bangor University, and conservation experts to make sure we got the best from the technology while protecting the site’s fragile environment and archaeology. We’re now very keen to share what we’ve learned with others.'

Backing British energy

Juliet Davenport OBE, founder and CEO of Good Energy, said: 'This project shows that cutting-edge British renewable technology can transform the energy use of some our oldest buildings.

'It’s a pleasure to be part of this project with the National Trust and we look forward to seeing what the next step in their renewable energy journey will be.'

The remaining pilot projects in our Renewable Energy Investment Programme are expected to be completed within the next year. If they are successful, we plan to invest in 43 renewables schemes at the places we look after.

Find out more about our pilot projects

Our commitments to clean energy

We have committed to reducing our energy use by 20 per cent, halving fossil fuel consumption and generating 50 per cent of our energy from renewable energy sources by 2020.

This will enable us to reduce our energy costs by more than £4 million per annum, releasing more money for our important conservation work across England, Wales and Northern Ireland.

Patrick Begg, our rural enterprises director, said: 'This is a transformative scheme. I couldn’t be more delighted that Plas Newydd – a really sensitive and special place – is not only converting to clean energy, but taking the lead on innovation.

'It’s clear to us that we need to make big changes so that we can continue to protect our treasured places and tackle the impacts of climate change. This successful scheme marks a major step forwards in our clean energy journey.'

You can help us on our journey

Our four million members are able to support the programme by signing up for renewable electricity with our energy partner, Good Energy. The company will pay the Trust up to £40 per year for each new customer signing up to its dual fuel tariff via the National Trust.

Find out more about how you can help cut your own use of fossil fuels and help support our clean energy programme.