National Trust powers mansion with Britain’s biggest marine source heat pump

A major milestone will be passed today with the completion of the UK’s largest marine source heat pump, off the North Wales coast, to provide all of the power needed to heat the National Trust’s breath-taking Plas Newydd mansion.

The project is the first of five schemes to be completed in a £3.5m pilot phase of the charity’s Renewable Energy Investment Programme, which was launched last year in partnership with the 100% renewable electricity supplier Good Energy.

Swapping oil fuel for sea energy
Plas Newydd was formerly the National Trust’s biggest oil consumer. On some winter days the 18th century mansion was consuming around 1,500 litres of oil a day – the same as a typical house would use in ten months.

Now it will be heated with the 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 30metres 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 the charity around £40,000 a year in operating costs, which can be ploughed back into the conservation of this elegant mansion, from its military uniform collection to a cricket pavilion on the estate.

A landscape first approach to renewables
Adam Ellis-Jones, Assistant Director for Operations in Wales at the National Trust, 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, 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 innovation
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 the Renewable Energy Investment Programme are expected to be completed within the next year. If they are successful, the National Trust plans to invest in 43 renewables schemes at the places it looks after.

The Trust’s five pilot projects are:

  • Plas Newydd – 300kW marine source heat pump, providing 100 per cent of the property’s heat requirements
  • Croft Castle in Herefordshire – 199kW biomass boiler, supplying 74 per cent of property’s heating needs
  • Ickworth in Suffolk – 199kW woodchip boiler, supplying renewable heat to Ickworth House
  • Hafod y Porth near Craflwyn in Snowdonia – energy from a 100kW hydro-electric scheme will be sold to the grid via National Trust (Renewable Energy) Ltd
  • Stickle Ghyll in the Lake District – 100kW hydro-electric project, expected to provide 30 per cent of the property’s energy needs, including the National Trust’s Sticklebarn pub

Clean energy commitments
The National Trust has committed to reducing its energy use by 20 per cent, halving fossil fuel consumption and generating 50 per cent of its energy from renewable energy sources by 2020.

This will enable it to reduce its energy costs by more than £4 million per annum, releasing more money for the charity’s conservation work across England, Wales and Northern Ireland.

Patrick Begg, Rural Enterprises Director at the National Trust, 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.”