Wimpole Estate cuts carbon emissions by 69% as National Trust aims for net zero

The Wimpole Estate is leading the way for the National Trust as it aims to become carbon net zero by 2030.

The estate has reduced its net carbon emissions by 69 per cent in four years - enough to heat and power 204 homes.

Switching to a ground source heat pump has saved it from using 35,000 litres of oil per year, while the largest solar panel installation in the National Trust is saving 50 tonnes of carbon dioxide equivalent (CO2e) per year.

The progress was confirmed while world leaders met in Azerbaijan for the COP29 climate summit.

Miranda Campbell, climate and environment adviser for the region, said: “What the team is doing at Wimpole is a great demonstration of what is possible, delivering a combination of renewable energy and efficiency, and land management, in a cost-effective way that is mindful of heritage, nature and people, as well as improving resilience to current and future climate impacts.”

In 2023-24, the Wimpole Estate reduced S1&2 carbon - which comprises direct emissions associated with energy and in-hand animals - more than any other National Trust site in the East of England and Midlands region, and was the fifth best nationally.

The reduction from 1,452 tonnes CO2e to 455 in four years has saved enough CO2 to fill Wimpole Hall 779 times.

Removing the old oil-fired heating and water system for Wimpole Hall and the Old Rectory Restaurant and installing a ground source heat pump using boreholes and heat exchangers has been one of the most significant changes.

The new system uses less than one-third of the energy used by the old oil boilers, cuts carbon emissions by 47 tonnes per year and saves more than £8,000 annually in fuel costs, while also removing the risk of an environmentally-damaging oil leak.

Providing low-temperature background heat via a heat pump is also better for the historic collection in the conservation charity’s care at Wimpole, compared to the fluctuating high-temperature heat generated from the fossil fuel boiler.

Positioning solar panels in the car park has maximised the harvesting of the sun rays, with a bank of inverters converting solar power into electricity that the National Trust uses to heat and power the visitor welcome building, along with an air source heat pump.

The solar panels also power electric vehicle charging points in the car park, with any surplus energy exported to the national grid.

Solar panels work on cloudy days too, so the system is generating electricity for the estate 365 days a year.

They provided 344,134kWh of electricity in 2023-24 - enough to meet the electricity needs of 111 average UK homes or 67 per cent of the electricity required by the estate.

Across the 1,000-hectare (2,471-acre) estate, the National Trust has changed how it grows crops to reduce carbon emissions and its impact on the environment.

Dave Hassall, farm and countryside manager at Wimpole Estate, explained: “The way we manage our land captures and stores an estimated 1,250 tonnes of CO2e per year. This is more than the emissions released by our fuel consumption (167), livestock (229), food and beverage (281), retail (60), gardens and outdoors teams (203) combined.

“In the last four years we have planted over 85,000 trees. As these trees get bigger, they capture and store more carbon each year.

“We expect our land sequestration to increase from 1,250 tonnes per year to 4,471 tonnes per year by 2030, which will take Wimpole well beyond carbon net zero, absorbing far more carbon in its land and habitats than it emits.”

The tree-planting project at Wimpole, funded by the government’s Green Recovery Challenge Fund and HSBC UK, is the National Trust’s largest and most diverse of its kind to date.

Meanwhile in the Walled Garden, measures to reduce water, light and energy consumption include the introduction of no-dig beds, switching from growing tomatoes to chillies - which need much less water and heat - in the glasshouse, and propagating plants in the house where possible.

A sustainable drainage system enables run-off water from the estate’s visitor car park to drain through ditches and swales into ponds. The water is naturally filtered and silt removed so it can be returned to nature without emitting extra carbon.

Inside the hall itself, portable radiators have been replaced with infrared heater panels and in the tallest rooms, ceiling fans have been added to bring down the heat to where it is needed..

Staff and volunteers have been given heated gilets to wear in cold weather, warming them rather than the whole space they’re working in.

Thick, lined curtains and blinds have been fitted to keep the heat in overnight and these can be used during the day when needed - also helping to keep rooms cool in hotter months.

More energy efficient technology has replaced the large walk-in fridge freezers In the café and restaurant, contributing to 42 per cent electricity savings in this area.

The National Trust - Europe’s largest conservation charity - says climate change is the single biggest threat to the places it cares for, prompting its pledge to reach net zero by 2030.