Commercial Solar Finance for NHS Trusts

Sector-specific funding

PSDS is the primary route — NHS England has been a significant PSDS recipient. The NHS Net Zero strategy provides additional internal funding mechanisms. Some integrated care system (ICS) capital programmes include decarbonisation. Salix Recycling Fund available. Greener NHS team coordinates portfolio funding.

Acute hospital trust, three sites. Combined 2.8MWp PV across estate roofs plus 1.5MWh battery storage at the main acute site for resilience and peak shaving.

PSDS application process

PSDS applications are submitted through the DESNZ Grant Management System. The application requires: a project description, a decarbonisation business case (carbon savings per £ of public investment), a funding breakdown, and an independent appraisal. Applications are assessed against carbon cost-effectiveness (£/tCO2e saved over 20 years). Solar PV combined with heat pump or LED lighting upgrades typically produces the strongest carbon cost-effectiveness scores — increasing the grant award probability.

Portfolio bundling for NHS applications

PSDS Phase 3 and 4 have favoured bundled portfolio applications — projects covering multiple sites under a single NHS Trust are evaluated more favourably than single-site applications, as they demonstrate economies of scale in delivery and management. A Trust with 8 acute and community sites submitting a portfolio solar application covering 2.5MWp total is more competitive than 8 separate single-site applications.

PSDS Phase 4: key constraints and deadlines

PSDS Phase 4 awards require project completion within a defined programme period (typically 18–24 months from grant award). NHS Trusts must plan for the DNO connection timeline (typically the critical path at 6–12 months) and construction procurement (OJEU/PCR threshold: NHS procurement above £5.3m requires full tender). Delays to construction risk grant clawback. Early engagement with NHS Shared Business Services (SBS) procurement framework reduces procurement timeline risk.

Procurement threshold requirements

NHS procurement is subject to the Procurement, Concessions and Contract Regulations 2024 (PCCR — successor to PCR 2015). Above the Works threshold (£5.3m), a full public procurement process is required. Solar projects below this threshold can use NHS framework agreements (NHS SBS, Crown Commercial Service, NHS Shared Business Services Energy Procurement) — typically much faster (4–6 months) than a full tender process. Most Trust solar projects fall in the £500k–£5m range and are procured via framework.

Net Zero Impact Assessment

NHS England's Greener NHS programme requires all capital projects above a Trust's internal threshold to include a Net Zero Impact Assessment (NZIA). Solar PV projects are straightforwardly compatible with the NZIA framework — the carbon saving calculation from solar displacing grid electricity is directly quantifiable and verifiable.

PSDS vs Salix direct loan: the NHS decision tree

Every NHS trust should first exhaust PSDS grant eligibility before moving to other structures. PSDS is non-repayable capital grant — it is categorically the best economics. The decision tree: (1) Is a PSDS round currently open? Check Salix Finance at salixfinance.co.uk. (2) Does your proposed project meet the CO2 cost-effectiveness threshold (typically under £100/tonne CO2 saved over project lifetime)? (3) Can you bundle solar with heat decarbonisation (heat pump, fabric measures) to score higher in the PSDS competitive round? If yes to all three: apply for PSDS first. If you miss the PSDS round or cannot bundle measures: use Salix direct 0% loan for solar-only projects. Only consider private sector lease/PPA if Salix access is exhausted or you need to move faster than the Salix application timeline allows.

Integrated Care Board (ICB) portfolio applications: the MAT model for the NHS

Just as multi-academy trusts can bundle schools into a single PSDS application, Integrated Care Boards can coordinate applications on behalf of their primary care estate. GP surgeries, health centres, and community clinics are all eligible PSDS assets — but individually, each project may be too small to score competitively. An ICB that bundles 20–50 primary care assets into a single portfolio application can: (1) achieve lower per-kWp installed cost through volume procurement; (2) present a compelling CO2 saving case at scale; and (3) create a management structure (the ICB as coordinating body) that Salix accepts. This model has been successfully used by several ICBs in Phase 3 of PSDS and is expected to continue in Phase 4.

NHS trust solar: the four numbers you need before any finance conversation

Before approaching any lender, Salix, or PPA developer, an NHS trust needs four numbers: (1) Annual electricity consumption by site in kWh — pull from ePIC or half-hourly meter data; (2) Available roof area in m² (structural survey required — NHS roofs are often heavily plant-loaded and smaller than they appear); (3) Current grid electricity tariff in p/kWh — including climate change levy (CCL) and distribution charges; (4) Heating fuel mix: % gas, % heat network, % electric — this determines the PSDS CO2 scoring potential. With these four numbers, we can model the annual saving, system size, best-fit finance structure and approximate PSDS score in under 30 minutes.