Renewable Energy Project at Osterley Park

View of the front of Osterley House

As part of the National Trust Renewable Energy Investment Programme, Osterley is installing a water-source heat pump in the Middle Lake.

A new water-source heat pump will provide reliable and energy efficient heating to the house and stable block at Osterley.

How will it work?

An array of coils will be installed in the Middle Lake which extract the natural heat produced in the water through heat transfer. Underground pipes bring this heat from the lake to the heat pumps in the basement of the house, which bring the water temperature up to suitable temperatures for conservation heating from the show rooms, and comfort heating for the cafe, shops and offices. Once installed, the parkland will be restored to its original state.

What are the benefits?

  • Reduction of Osterley’s dependence on fossil fuels by removing five gas-fuelled boilers.
  • Increase of oxygen production in the Middle Lake, with positive impacts on biodiversity.
  • Upgrade of an aging and costly system
  • Gain of Renewable Incentive Income from the government, as well as the reduction of overall cost, allowing for more funds being allocated to conservation work.

For more information on heat pumps visit Baystar Energy, with whom we are working on this project.

Latest updates

26 Mar 20

Week 12

Although Osterley Park and House is now temporarily closed to limit the spread of coronavirus, the renewable energy project has still been progressing over last week (week 11) and this week, meaning we are ever closer to heating the buildings in a sustainable fashion. Osterley’s heat pumps are now in their final position in the house – they are each about the size of a large washing machine, and they're sitting on mesh plates in order to absorb any vibrations to protect the floor and reduce the noise of the compressor (and to save the ears of our House Stewards, who live in the next room along!).

The heat pumps inside Osterley House

11 Mar 20

Week 10

The heating in the house has reinstated after being off for two weeks while we upgraded the gas boilers. We are keeping these boilers to top-up our heating during the coldest points of the year or for bringing hot-water cylinders from 50oC to 60oC for legionella management. All the radiators in the exhibition spaces are located in the horse-shoe corridor rather than in the show rooms, meaning that during the coldest parts of the year, the 50oC created by the heat pumps cannot sufficiently heat the furthest corners of the rooms. The heat pumps work on a weather compensation system whereby when it’s too cold outside, they tell the gas boilers to boost the heating to ensure the show rooms receive sufficient heat. We are hoping to use the gas boilers for less than 10% of the year.

The existing boilers will act to 'top up' heating

04 Mar 20

Week 9

We’re half-way through digging the causeway trench, back-filling as we go. Here is a picture of the header pipes before they get covered over – one brings the warmed liquid from the lake to the heat pumps (a ‘flow’) and the other takes the cooler liquid that has been processed through the heat pumps back down to the lake to be re-heated (‘a return’). This closed-loop system was preferred over an open-loop system (where the actual lake water is taken up to the heat pumps) to negate the need for an expensive and labour-intensive filtration system to remove all the silt, as well as the non-invasive nature of the closed system on the ecology of the lake.

REI project at Osterley - week 9