Solar Panels for NHS Trusts

The estates problem solar actually solves

The NHS has two net zero targets (NHS England, Greener NHS): net zero by 2040 for the emissions it controls directly (the NHS Carbon Footprint), with an 80% reduction between 2028 and 2032, and net zero by 2045 for the emissions it can influence (the NHS Carbon Footprint Plus), with an ambition of an 80% reduction between 2036 and 2039. Capital for trusts is also tightly controlled. Rooftop solar is one of the few measures that can serve both, because it can be funded from outside the trust's own capital and the savings land on the trust's energy line. The Public Sector Decarbonisation Scheme paid for many such projects until Phase 4 closed to new applications in 2024; the Great British Energy NHS solar window closed on 22 June 2026 (see below).

A hospital's electrical profile suits PV. Theatres, imaging, ITU ventilation and sterile services create a high, flat baseload through nights and weekends, so a large share of what rooftop PV generates is used on site. How much of a trust's annual electricity a rooftop array covers depends on roof area and demand; at acute scale, where annual electricity spend can run into millions of pounds, even a modest share is meaningful. Half-hourly data, not a rule of thumb, gives the number.

What each estate type takes

On this site's illustrative model (see the costs page for every assumption): acute hospitals fit roughly 300 kW to 2 MW of PV at £250,000 to £1.6m, with multiple buildings on one estate allowing phased installation. Community hospitals and polyclinics fit 100 to 500 kW at £90,000 to £450,000; their daytime-heavy diagnostic and outpatient profile gives good on-site use for their size, and modern flat-roofed buildings make delivery easier. Mental health units fit 100 to 400 kW at £90,000 to £360,000 with strong 24/7 baseloads, plus the specific safeguards covered in the questions below. GP surgeries and health centres fit 20 to 80 kW (£22,000 to £90,000) and usually involve a landlord conversation with NHS Property Services or a LIFT company before anything else. These are planning ranges, not quotes.

Governance: where hospital solar projects stall

Hospital solar projects rarely fail on engineering. They stall in governance: a business case that does not survive Green Book scrutiny, a PFI energy clause nobody checked, an ICB approval that arrives after a funding window has closed. A Trust Board paper normally needs the NPV, IRR, simple payback, the contribution to net zero targets, the ERIC impact and the funding route, with HM Treasury Green Book treatment. PFI energy-risk allocation should be checked before design spend. And the approval chain (Trust Board, Integrated Care Board, regional NHS England team and the PFI partner where relevant) belongs in the project programme from day one, which is why the sequence on the process page is organised around governance steps as well as installer steps.

Where NHS solar funding stands

PSDS Phase 4 took applications from 9 October to 25 November 2024 and is now closed to new applications; awards already made continue to be delivered (gov.uk scheme page). No Great British Energy NHS solar application window is open now. The rounds so far in the Great British Energy solar programme run with NHS England: £100 million in a first round announced in March 2025 (NHS England), an extension in 2025, and a further £25 million for 2026/27 whose application window closed on 22 June 2026 (HEFMA). Ask your regional Greener NHS lead where the programme stands.

We could not confirm that any Salix loan route is currently open to NHS trusts in England, so ask Salix whether one is open to your trust before you put one in a business case. The funding page compares the routes side by side.

HTM compliance and clinical continuity

Work on a live hospital site is expected to follow HTM 03-01 infection-control practice: contractor induction by the Estates and infection-prevention teams, segregated construction zones, and maintained negative-pressure areas where they apply. Wards, theatres and ITU normally keep running during roof work; the usual operational touchpoint is the final grid connection, which is planned with Estates and theatre management as a scheduled window. Electrical design on healthcare premises is expected to be reviewed against HTM 06-01 (electrical services supply and distribution), and trusts normally involve their Authorising Engineer (Electrical), the AE(E), in reviewing and authorising new generation connected to the hospital distribution system. Trusts typically expect Enhanced DBS clearance for contractors working in patient areas, with Barred List checks for children's and mental health settings. Ask any bidder how this is evidenced across the whole on-site workforce, not just the supervisors.

Evidence an estates team should have ready

• Twelve months of half-hourly electricity data for each site, covering winter heating and summer cooling peaks.
• Roof drawings and, ideally, a structural and services survey (see the roof survey guide).
• The single-line diagram, the generator and UPS arrangement, and the connection capacity at each site.
• The trust's Green Plan wording on solar and the Board's scheme of delegation for capital.
• For PFI sites, the energy-risk and roof-alteration clauses in the contract.
• A named procurement route (see the procurement guide).

The combined heat pump and PV route

Heat pumps displace gas and oil heating, and rooftop PV supplies part of the electricity they use, so the two are usually modelled together. PSDS, which closed to new applications in 2024, was designed mainly around low-carbon heat, and projects already awarded continue. For a trust planning new work the same pairing is still sensible engineering: if the Green Plan includes heat decarbonisation, as most do, modelling PV alongside it shows the true load and the true saving. The funding page covers the current routes and dates; costs and payback sets out the arithmetic behind each estate type. See also Greener NHS for regional contacts.