News

Reducing the environmental impact of powering our hospitals 20 Nov 2025

• Multi-year decarbonisation programme set to reduce greenhouse gas emissions from powering the Trust’s hospital buildings and equipment by 43 per cent compared to 2020/21 levels
• £47m being invested this year and next to continue overhauling energy systems and reduce risk of estate failure, bringing total investment to £120m since 2021
• Trust data shows a 27 per cent reduction in building energy greenhouse gas emissions at Charing Cross Hospital alone between 2023/24 and 2024/25

Imperial College Healthcare is investing £47.4 million over the next two years to continue overhauling its hospitals’ energy systems and reduce estate risks, thanks to funding secured from Public Sector Decarbonisation Scheme (PSDS) and NHS England. This will allow for the installation of more heat pumps, solar panels and better gas and electricity controls - replacing some existing gas-fired heating and hot water systems with more sustainable and renewable energy sources.

The latest works are part of a £120 million decarbonisation programme which began in 2021. The Trust estimates that this programme, once completed, will reduce greenhouse gas emissions from heating, cooling and powering hospital buildings and equipment by 43 per cent. This is a saving of 20,233 tonnes of CO2e (carbon dioxide equivalent) a year, which is equivalent to the energy used to power and heat 8,085 average UK homes for year. This puts the Trust well on track to meet NHS England’s 2032 target of reducing directly controlled greenhouse gas emissions by 47 per cent.

In 2025/26 and 2026/27, in line with the estate investment plan, the Trust is:

• installing two additional heat pumps at Charing Cross Hospital, plus more heat pumps and the first solar panels at Hammersmith Hospital
• improving insultation and cooling systems at Charing Cross and Hammersmith, improving energy efficiency
• installing LED lighting and better gas and electricity controls across all the Trust’s hospital sites, reducing energy consumption and brightening spaces.

Some of the Trust’s buildings are over 170 years old and much of the energy infrastructure is at the end of its lifespan, inefficient and insufficient for modern healthcare. In line with the Trust’s Green Plan, over £110 million has been secured in grants to decarbonise the estate since 2020/21, backed by an additional £9.48m of Trust capital.

The focus of the works to date have been Charing Cross and Hammersmith hospitals, where the updated energy infrastructure can be incorporated into and benefit the two sites’ wider redevelopment plans (a mix of major refurbishment and new build). In contrast, the St Mary’s redevelopment is a complete rebuild, which limits the scope of immediate major decarbonisation work. However, St Mary’s will benefit from the new LED lights and better gas and electricity controls which are being rolled out across all the Trust’s sites.

Professor Bob Klaber, director of strategy, research & innovation and net zero lead at Imperial College Healthcare NHS Trust, said: “We are one of the biggest NHS Trusts in the country and are strongly committed to reducing our impact on the environment through a range of schemes linked to our Green Plan.

“Decarbonising our hospital buildings is a key part of this. I'm incredibly proud of our teams who have been able to secure over £110m funding since 2021, and of their expertise in delivering the schemes that are achieving such impressive impact.”

Eric Munro, director of estates and facilities at Imperial College Healthcare NHS Trust, said: “Decarbonising our estate is a complex task, with many of our buildings rapidly ageing and reliant on outdated, inefficient gas boilers. But the benefits are clear – it is curbing our impact on the environment, improving the resilience of our energy supply and reducing the risk of estate failures.

“We have already seen huge benefits at Charing Cross Hospital, where most of our work has been focused so far. In the last year (24/25) there was a remarkable drop of 27.5 per cent reduction in greenhouse gas emissions related to powering the hospital. For the wider Trust, we expect to see a reduction of around 43 per cent compared to 2020/21 when we started our multi-year decarbonisation programme.

“This is an extraordinary achievement and the result of many years of hard work from colleagues across the Trust, especially our sustainability and estates teams and partners including Dalkia and CBRE.

“The Government has recently said that it will not be committing further investment for the PSDS, but they have confirmed that all current awards including ours will remain fully funded and that they are looking to build on the progress of the PSDS. We remain committed to working with the Government and partners to identify investment to maintain momentum.”

Further information

What are heat pumps and solar panels, and why are they more environmentally friendly?

A heat pump is a much more energy efficient, low-carbon and renewable alternative to traditional gas boilers. They use electricity to take heat from the ground or air around a building and convert it to a temperature that can provide heating, cooling or hot water to buildings. Solar panels are also a renewable energy source, which creates no greenhouse gas emissions.

The Trust has also benefited from a range of accompanying enabling works to the energy infrastructure of the hospitals, prior to the installation of the heat pumps and solar panels, which has improved energy efficiency and contributed to reduced carbon emissions.

Case study: electrification of heating systems at Charing Cross Hospital

The full benefits of this work won’t be seen until the two further heat pumps are installed over the next couple of years. But Trust data shows that there was a 27 per cent reduction in building energy emissions at Charing Cross Hospital alone between 2023/24 and 2024/25, the first year following the first phase of heat pumps going live. At the same time, there was only a very small increase in electricity usage.

Appendix: decarbonisation funding breakdown

**All data and info on emissions related to the greenhouse gas emissions in tonnes of CO2e from gas, electricity and oil consumption at our three main sites (including the Western Eye Hospital).