In 2012 the National Trust embarked on its largest solar power project to date and teamed up with Prescient Power, a renewable energy projects installer based in the East Midlands, in order to help the charity to reduce its reliance on fossil fuels.

As part of the project, Prescient Power developed, designed and installed PV systems at six National Trust sites — Cwrt Farm (42kW), Penryhn Castle (50kW), Powis Castle (39kW), Hafod Y Bwch (16kW), Dinefwr park and castle (50kW) and Plas Newydd Country House and Gardens (50kW) — which have a combined capacity of 247kW.

All the projects were off-grid, ground-mounted solar arrays, with the exception of the system at Cwrt Farm, which was installed atop a traditional farm building on a roof made from corrugated concrete fibre.

In total, the six installations will generate more than 212MWh of electricity a year, helping the National Trust cut its carbon output by 120 tonnes per annum and reduce its electricity bills by more than £20,000, the organisation claims. It also expects the installations to help generate £73,000 each year through feed-in tariff payments.

Work began on the first of the six installations at Plas Newydd on 7 February and by 29 February all six sites had been commissioned.

However, during the planning and development phase, Prescient Power faced several challenges due to the historic and environmental importance of the sites. As a result, it was imperative to carefully design a system that was sensitive to the locations whilst maximising the output. Taking this into account, it was clear that each system had to be custom designed, thus presenting its own unique challenges. 

At Penrhyn Castle, it was important that the solar panels were installed on an area which did not impact the views of the castle or be seen from the castle. As a result, the solar array was installed in the car park, which is not visible from the castle. The 50kW system generates enough electricity to supply 25% of the castle’s energy demand.

Meanwhile, at Cwrt Farm, a similar challenge arose. The farm is situated within a national park on the flanks of Snowdon, the highest mountain in Wales. With 60,000 walkers looking down on the farm, it was important to not disturb the natural surroundings too much. And without a car park to solve the problem, the developers had to seek out a different solution.

In the end, black solar panels with dark frames mounted on an anodised mounting system were selected to help the panels blend with the colour of the roof of the farm’s sheds.

The design has been a success and “people keep passing it without noticing”, Justin Albert, Director of the National Trust in Wales, says. “We need the energy but don’t really need to see it!”

Prescient Power also highlights the difficulties concerning wildlife. The site of Hafod y Bwch has been deemed as a likely habitat for great crested newts, a species protected by law. A plan was prepared by specialists and care was taken around the site during trenching with everyone on standby to temporarily re-site the newts to a specially made hiberculum — if they came across any.

In addition, an archaeologist was available on the majority of the sites during trenching for the cables to check for artefacts excavated during the work.

Prescient Power says that creating a network of experts was key to the successful implementation of the projects “with consultation sought with architects, local councils, designers, accountants, lawyers, newt specialists, bat specialists, tree specialists, botanists and fencers to name a few”.

Carl Benfield, Managing Director at Prescient Power, adds: “Most, if not all of the National Trust properties have their unique sensitivities, whether that be a historic building, picturesque surroundings, protected flora and fauna, or economic heritage. We needed to work alongside custodians at each site, understanding their priorities and explaining how the installation would operate.

“We were fortunate. The trust has some of the most dedicated, warm and engaging people we have met. In every case we were able to have well articulated discussion on how to minimise short term disruption and allow the estate reduce its costs and increase its revenue.”

To date, the National Trust has installed solar arrays at 12 of its sites in Wales including the six Prescient Power installations. In total, they have a combined capacity of 350kW. However, plans do not stop there. The National Trust has identified an additional 47 sites in Wales to be equipped with solar and has already received planning permission for two sites at Mathry ranger base in Pembrokeshire and Llyndy Isaf Farm in Beddgelert.

Commenting on the switch to solar, Keith Jones, Environmental Advisor for the National Trust, says: “Solar is a perfect match for the National Trust. When the sun is out, the visitors are out. And when the visitors are out, that’s when we really need the energy.”