NHS Green Plan: Where Rooftop Solar Fits in a Trust Estate

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. For most trusts the target now has an owner (the Green Plan, through Greener NHS), a reporting mechanism (ERIC returns and the annual Green Plan submission), and a problem: the delivery routes are far less clear than the targets.

This article is about the one delivery route that is genuinely straightforward, what it contributes, and — just as importantly — what it does not.

What solar contributes to a Green Plan

The health estate's electrical footprint is large, and rooftop solar attacks it directly. How much of a hospital's annual electricity a correctly sized array delivers depends on roof area and demand, and half-hourly data gives the number. Because clinical estates run 24/7 baseloads (theatres, imaging, ITU ventilation, sterile services), a large share of generation tends to be used on site, displacing purchased grid electricity at full retail rates.

What the Green Plan guidance asks for

NHS England's Green plan guidance (published 4 February 2025, updated 8 May 2025) asks each organisation to set specific, measurable, time-bound actions for each area of focus, with indicators, to review and update the plan annually, and to have a designated board-level net zero lead, generally an existing executive director. It names investing in on- or near-site renewable energy generation to meet NHS energy demand as a focus, and notes that the Health and Care Act 2022 placed duties on ICBs, trusts and foundation trusts to consider statutory emissions and environmental targets in their decisions. A system plan is not meant to be a stack of trust plans; it has to cover the ICB's own leadership role.

Where the NHS stands

NHS England's progress review of 24 September 2025 says all trusts and ICBs now have a Green Plan and must report progress to their boards each year, and that the NHS Carbon Footprint was 68% below its 1990 baseline in 2024/25 against an 80% target for 2028 to 2032. It also says gas, mostly for heating, was about 40% of the footprint and has barely moved, which is why a solar line has to sit beside a heat line. The NHS net zero explainer sets out those figures.

How the solar line of a Green Plan should read

• Name the sites and the roofs. A line that says "install solar" cannot be delivered; one that lists surveyed roofs can.
• State the owner and the date. Who in estates owns it, and which financial year it lands in.
• Say how it is funded. Great British Energy rounds, trust capital or a power purchase agreement, with the evidence needed for each (see the tracker).
• Pair it with heat. Solar supplies part of the electricity a heat pump will use; the plan should show both.
• Measure it. Generation and the electricity it displaces, from the trust's own meter data.

In Green Plan terms, that shows up in three places:

• Scope 2 emissions fall in direct proportion to displaced grid electricity
• ERIC metrics improve — energy use intensity (kWh/m²) and CO2 intensity both track downward
• The finances reinforce the plan — energy savings recycle into the next decarbonisation measure, which is how mature Green Plans become self-funding programmes rather than annual capital fights

What solar cannot do

A Trust cannot panel its way to net zero. Covering only a share of electrical load, rooftop PV is a meaningful contributor, not a solution — and electricity is only part of a hospital’s emissions, with heat usually the larger and harder share. Trusts that treat solar as the headline act tend to produce Green Plans that look active while the gas boilers keep running.

The mature sequencing treats solar as the enabling layer for heat decarbonisation. Heat pumps electrify the heating load; solar supplies a portion of that new electrical demand at low marginal cost. Public Sector Decarbonisation Scheme applications were designed mainly around heat, with solar eligible alongside it, which made the combination a natural fit for that scheme (it has now closed; see the funding page for what is open).

Sequencing the estate

Most Trusts hold a mixed estate — an acute site or two, community hospitals, mental health units, and a primary care portfolio with complicated ownership. They cannot do everything at once, and they should not try. A defensible sequence:

1. Acute sites first for scale. 300 kW–2 MW systems, the deepest savings, and the flagship evidence for the Green Plan. Multi-building campuses can phase the install.
2. Community hospitals for speed. Modern flat-roofed buildings, 100–500 kW systems, faster delivery, and daytime-heavy loads that match generation well.
3. Mental health units with the right contractor. Same economics, additional safeguards: Enhanced DBS with Barred List checks, Mental Health Act awareness, anti-ligature design considerations during works.
4. Primary care last, with landlords. GP surgeries and health centres at 20–80 kW often involve NHS Property Services or LIFT company consent before anything else — start the conversations early, deliver late in the programme.

Governance: where Green Plans stall

The pattern is familiar: a Green Plan names solar, an estates officer obtains quotes, and the scheme dies in governance because the business case was never built for the audience that approves it. Trust Boards approving capital of this size need NPV, IRR, payback, the funding pathway, ERIC impact and HM Treasury Green Book treatment. PFI sites need the energy risk allocation checked before design spend: if the PFI partner pays the energy bill, the savings flow to them, and the scheme only works as a structured co-investment.

None of this is difficult, but all of it must be done in order: feasibility, funding route, governance pack, procurement, delivery. The process page maps the sequence, and the NHS Trusts page covers the estates detail by site type.

The 2028 to 2032 arithmetic

The interim target is the one that should drive behaviour. Net zero in 2040 feels distant; an 80% reduction between 2028 and 2032 does not, and every year a viable solar scheme sits unbuilt is a year of emissions the trust must recover somewhere harder. Funding windows are short and delivery deadlines are hard, as the PSDS Phase 4 window (9 October to 25 November 2024) and the 2026/27 Great British Energy round (closed 22 June 2026, projects finished by 31 March 2027) both showed, so the schemes that contribute earliest are the ones whose evidence was ready before the window opened.

The estates teams hitting their trajectories are not the ones with the most ambitious plans — they are the ones who turned one page of the plan into a feasibility study this quarter. If that is where your Trust is, start with the data.