Five insights into NHS energy performance and the challenges ahead to achieve Net Zero

Jack Magill – Energy Solutions Senior Analyst at EDF

At 5.4% of the total, the NHS contribution to UK CO₂ emissions is one fifth above the global average for healthcare (The Guardian). This prompts the question, is the NHS doing enough to manage its carbon impact? Given its substantial contribution to UK emissions and the clear links between climate change and public health, the NHS has an opportunity to lead by example in the quest for Net Zero. In this article, I’ll share 5 insights from the Estates Returns Information Collection (ERIC) data of the last three years to highlight energy-related performance with a particular focus on sustainability and the aim for a greener NHS.

1. 2019 Snapshot

In 2019 the total cost of running the NHS estate was £9.5 billion, up from £8.8 billion the previous year, with energy costs making up around 6.5% of this total. Its energy related carbon footprint was equivalent to the amount of carbon sequestered by forests covering an area ten times the size of London. The graph above also highlights the large variance in energy spend across different site types, with general acute hospitals spending significantly more than any other site type.

2. Oil use is still prevalent, and 2 sites still consume coal.

A key part of the NHS journey to become greener will be reducing its reliance on fossil fuels. Although the discussion around fossil fuels is rightly focused on gas, reducing the use of oil and even coal are still on the sustainability to do list. In fact, phasing out the use of oil and coal-fired boilers is specifically referenced within ‘For a Greener NHS’, an initiative launched earlier this year aimed at driving the changes required to achieve Net Zero.

The map above shows 41 sites that were consuming more than 250 barrels of oil annually while 2 sites were still consuming coal. Oil is more commonly used as a resilience fuel in the event of a gas supply failure, however, there are still sites using it as a primary fuel for heating. With all fossil fuels comprising around 70% of the organisation’s energy mix, substantial changes need to be made to how the NHS powers its operation. As the carbon intensity of the UK electricity grid decreases through the penetration of renewables, embracing the electrification of heat and transport in particular provide two ways in which the NHS can do this.

3. Energy efficiency has been steadily improving.

In recent years, climate change has come to the forefront of both the political and corporate agenda. This has led to stringent sustainability targets for public sector bodies, amplifying the need for the NHS to first understand and then optimise its energy use.

The good news is that over the last 3 years, its energy efficiency has been steadily improving. As a measure of efficiency, I’ve divided gas and electric kWh by the area of the buildings. The kWh/m² for both gas and electric has been trending downwards during 2017-19, with 7 of 8 site types seeing an improvement in their electric efficiency, whilst 6 of 8 improved their gas efficiency. However, the largest improvements are concentrated in the less common site types with smaller energy costs. General acute hospitals which as we’ve seen are the biggest consumers of energy have only seen a modest improvement in electric efficiency, with gas efficiency falling.

4. Green breeds green

Across the estate, there are approximately 1000 EV charge points installed. The benefits these provide are numerous. They provide a charging infrastructure for those hospitals that have already electrified their fleet and a means of generating income from EV drivers paying to charge their vehicles. Furthermore, installing charge points enables the use of electric cars which brings a reduction in carbon emissions as they replace those powered by combustion engines. This demonstrates the positive impact on public health the NHS can have beyond healthcare and furthermore, a hospital car park full of electric vehicles sends a positive image of the NHS as a sustainability leader.

In 2019, 14% of sites with existing EV charge points invested in more charge points whereas only 3.1% of sites without existing charge points installed their first in 2019. Is this because those with existing charge points already understand the benefits and were keen to maximise them? Is it because the perceived challenges of the first project had been overcome and were no longer a barrier? Is it that the sites installing more charge points have electrified their fleet and require the infrastructure for charging their own vehicles?

5. On-site generation capability is significant but dominated by CHPs

As the UK grid evolves into an increasingly flexible and renewables-dominated system more power will be consumed closer to, or at source. This transition brings with it many uncertainties but by beefing up its onsite generation capacity the NHS can maintain its security of supply, mitigate the impact of rising non-energy costs and have more control over the carbon intensity of its energy use.

Onsite electricity generation currently meets 24% of consumption needs, but over 99% of this comes from gas-fed combined heat and power plants (CHPs). Furthermore, since 2017 new CHP investments have outstripped new renewables investments with 17 sites adding a CHP whereas only 3 made their first investment in renewables. This demonstrates the ongoing importance of CHPs to the NHS but further highlights the current reliance on fossil fuels. Ensuring CHPs are increasingly powered by renewable fuels like biogas and hydrogen will mean they can form a key part of the energy operations of a greener NHS. Combining this with increased investment in renewable generation such as solar will result in substantial ‘green’ onsite generation capacity to complement low carbon energy sourced from the grid.


The NHS faces a huge challenge to meet the healthcare requirements of a growing population with tight budgets, amplified by the covid-19 pandemic. However, as it emerges from one crisis another looms large, with the need for shared action to tackle climate change increasingly urgent. Given its contribution to UK emissions, a more sustainable NHS will have a considerable impact on national efforts to achieve Net Zero.

As the analysis shows, positive strides have been made in improving energy efficiency but overall engagement with energy solutions has been sporadic and the use of fossil fuels is still widespread. However, the launch of the ‘For a greener NHS’ campaign earlier this year should prove a catalyst for more widespread action. For those Trusts already reaping the benefits of investments in sustainability and energy solutions, there is an opportunity to look beyond improving the performance of their hospitals and to assume the role of a sustainability leader. By sharing their experiences and lessons learned, they can smooth the path for other Trusts to take similar action, ensuring that the benefits are distributed throughout the wider NHS to the benefit of everyone.

A note on ERIC data

ERIC is a data set compiled each year by the NHS Trusts. It comprises information relating to the costs of running the NHS estate including maintenance of buildings, the provision of services and the costs and consumption of various utilities.