Kelmarsh Hall is a Grade I listed country house built in 1732 located in the heart of the 3,000 acre Kelmarsh Estate. The Estate is now in the care of a charitable trust, charged with maintaining it in perpetuity for the benefit of the nation.

The Estate contains numerous areas of high conservation value. All of the estate woodlands along with the park and wilderness lake are designated local wildlife sites and support many local Biodiversity Action Plan (BAP) Species.

In 2004, Kelmarsh (Events) Limited was set up as a commercial arm of the business to support the Charitable Trust. The Kelmarsh Trust’s main aims and undertakings are to:

  • conserve and manage the built and natural environment
  • promote education about the hall, the estate and its natural history
  • provide public access


Why Renewable Energy?

“Historically Kelmarsh Hall used an oil fired boiler to provide its heat and hot water. Not only was this expensive, with an oil bill of £30,000 a year, it was also difficult to control. It was either too hot or too cold with no middle ground!” explained Lesley Denton, General Manager, Kelmarsh Hall.

The Hall and one of the wings, which is rented to a private tenant, was heated by the same system. “If our tenant turned the heating up or down this effected the temperature of the Hall,” added Denton.

As well as wanting to reduce the Hall’s energy costs, the Trustees were very keen to reduce its carbon footprint.

Importantly, a switch to renewable energy would not only reduce the Hall’s operating costs it would also ensure that the Trustees’ achieve their aim to ‘conserve and manage the built and natural environment’ of the Estate.

From a financial perspective a move to a renewable energy system would mean that the Estate could take full advantage of the non-domestic Renewable Heat Incentive (RHI). This Government initiative pays a tariff, over 20 years, for every kilowatt hour (kWh) of energy generated by renewable energy.


The Solution:

Through the Historic Houses Association one of the Estate’s Trustees was already aware of renewable energy specialist Ecovision Renewables which operates nationally from its base in Gloucestershire on the Highgrove Estate.

“We arranged an initial meeting with Ecovision and it was immediately clear that its experienced team had the expertise to guide us through the appropriate renewable energy options for a large country house such as Kelmarsh Hall,” said Denton.

“We did look at another supplier only to find that they specialised in new builds. They were also sceptical that a renewable energy solution would operate efficiently without the added expense of installing double glazing, insulation and modern radiators,” added Denton.

With an existing logging business on the Estate, it was felt that Kelmarsh Hall would benefit from the deployment of a biomass boiler which could be fed by wood from the Estate’s own managed woodland.

However, after calculations were carried out detailing the loss of income from log sales, the ongoing costs of producing its own wood chip, the realisation that the available space to house the biomass boiler was too small and that the construction of a new plant room would prove problematical as the Hall is a Grade 1 Listed building, it was clear that biomass was not an option.

Ecovision quickly recommended that the Trustees looked at another of the Estate’s natural resources, water from its lake, to fuel a Water Source Heat Pump (WSHP). The lake’s proximity to Kelmarsh Hall and the suitability of its flow and depth made it an ideal source of renewable energy.

“We were already planning to upgrade the Hall’s electrical supply which meant that we would have a dedicated three phase supply for the WSHP,” Denton said.

The work to install the WSHP had to be carried out around Kelmarsh Hall’s 2012 summer season when the lack of heating would not be an issue.

To extract the heat from the water in Kelmarsh Hall’s lake to fuel the WSHP, Ecovision placed 32 x 200 metre loops filled with polypropylene glycol which, importantly is a non-toxin so any potential risk of harm to the lake’s resident fish was eliminated, into the lake where they sank into the correct position.

A 145 metre trench was then dug from the plant room housing the heat pump, located in the basement of the Hall, and pipes laid to connect the heat pump to the loops in the lake.

The ground work was successfully completed in a short two week window between weddings and other events taking place within Kelmarsh Hall.

The WSHP solution was commissioned in September 2012 with all the work being completed in approximately 12 weeks.


The Benefits:

Kelmarsh Hall can now be kept at a constant temperature. Crucially, with separate controls for the rented wing, the conservation and management of the built environment of the Hall is easily achievable.

“Contrary to the advice given to us by the other renewable energy supplier we consulted, Ecovision’s installation connects the WSHP to our existing cast iron radiators and works extremely efficiently!” commented Denton.

Renewable energy plays a key role in helping to reduce Kelmarsh Hall’s previous carbon footprint by an estimated 50%.

“The total cost of the WSHP installation, including the ground works was £185,000 but, taking into account our savings in oil and electricity costs plus the RHI payment which is linked to the Retail Price Index, our renewable energy solution will pay for itself in five years or less,” explained Denton.

Once the WSHP has paid for itself, the RHI payments continue for a further 15 years and combined with the savings in fuel costs over that period the WSHP will provide Kelmarsh Hall with an additional income in excess of £700,000.

“We are very happy with the renewable energy solution which Ecovision has installed. It has delivered all that we wanted it to including a 19% return on investment, over 20 years, on our original investment,” concluded Denton.


For more info contact: Ecovision Renewables on 01666 501580