Public sector — Salix Finance

Salix Finance for commercial solar UK 2026

Interest-free loans for NHS, schools, councils and universities to fund solar, heat pumps and battery storage. PSDS Phase 4 closed in 2024 — but Salix BAU loans remain open with no end date. Repayments are sized to match your energy savings. Net cost: £0.

Interest on BAU loans — not subsidised rate, literally zero

Open

BAU loans — rolling fund, no competitive rounds, no end date

£50k+

Minimum project size — no upper cap on BAU loans

Free Salix eligibility check Full Salix funding guide

4.9 · 47 Google reviews

180+

Projects

£42m

Secured

4.5yr

Avg Payback

MCS NICEIC RECC TRUSTMARK

PSDS is closed — Salix BAU is open. These are different things.

The Public Sector Decarbonisation Scheme (PSDS) Phase 4 closed to new applications November 2024. PSDS was a capital grant programme administered by Salix Finance. It is not coming back imminently. Salix Business As Usual (BAU) interest-free loans are entirely separate and remain open. If you've been told "Salix is closed" — you were told about PSDS, not Salix BAU.

Salix BAU loan terms

Interest rate

Zero interest for the full loan term — not subsidised rate, literally zero.

Loan term

5–12 years

Set to match modelled energy savings, so repayments equal savings from day one.

Project minimum

£50,000

No upper limit for BAU loans. Very large projects (£5m+) may use structured tranches.

Repayment

From energy savings

Salix model: annual loan repayment ≤ modelled annual energy saving. Net cash flow neutral or positive from commissioning.

Eligible measures

Solar, heat pumps, LED, BESS, controls

Whole-building projects preferred. Solar-only eligible. Co-located BESS strengthens case.

Application window

Open — no end date

BAU loans are a rolling fund. No competition rounds. Applications assessed on technical and financial merit.

Who is eligible for Salix Finance?

NHS Trusts & Foundation Trusts

Acute, mental health, community, ambulance. Projects from £100k to £10m+. BAU and Salix net zero fund both available.

Local authorities

District, county and unitary authorities. Includes council housing stock. BAU loans for council buildings, leisure centres, offices, depots.

Schools and academies

Maintained schools, academy trusts (including MATs with 10+ academies), sixth form colleges. MCS-certified installers required.

Further and Higher Education

Universities, FE colleges, specialist colleges. HEFCE successor bodies. Salix HE loans available through UCEA-recognised process.

Housing associations

Registered providers of social housing with Regulator of Social Housing registration. Community assets eligible via GBE pathway.

Emergency services

Police, fire and rescue, ambulance trusts. Public sector building stock including stations, control rooms, training centres.

How Salix Finance for solar works in practice

Eligibility check

We confirm your organisation is a qualifying public sector body and the project meets Salix minimum criteria. Usually 24 hours.

Energy survey and modelling

We survey the building and model the solar generation, self-consumption, and energy savings. This forms the core of the Salix application.

Application preparation

We draft the full Salix BAU application — technical specification, energy model, installer quotes, financial modelling, CFO sign-off forms.

Installation and handover

After Salix approval, installation begins. Salix releases funds directly to the installer. Repayments start post-commissioning from energy savings.

Salix Finance and solar: worked example — 250 kWp secondary school

Site: 1,200-pupil secondary school, South East England
System size: 250 kWp rooftop solar + 100 kWh BESS
Gross installation cost: £187,000 (solar) + £65,000 (BESS) = £252,000
0% VAT applied: saving £43,000 — quotes issued at 0% VAT
Net cost to Salix: £209,000
Modelled annual energy saving: £38,500 (grid import displacement + SEG income)
Salix loan term: 6 years at £34,833/year (≤ modelled saving)
Net cash impact year 1–6: Savings £38,500 − repayment £34,833 = +£3,667/year positive cash flow
Net cash impact year 7–25: £38,500/year saving with no loan repayment — £731,500 total benefit

Salix Finance solar FAQs

What is Salix Finance and who can apply for solar funding?

Salix Finance is a government-owned company that provides interest-free loans to public sector organisations to fund energy efficiency and low-carbon technology. Eligible bodies include NHS trusts, local authorities, schools, academies, universities, FE colleges, housing associations and emergency services. Applications for the Business As Usual (BAU) loan fund are open year-round with no competitive rounds and no announced end date.

Is Salix Finance still available after PSDS Phase 4 closed?

Yes — Salix Finance BAU loans are entirely separate from the Public Sector Decarbonisation Scheme (PSDS), which closed to new applications in November 2024. PSDS Phase 4 was a grant scheme administered via Salix. BAU loans are a rolling loan fund that predates PSDS and continues to operate. Public sector bodies can apply for BAU loans regardless of whether they received PSDS funding previously.

How does a Salix interest-free loan work in practice?

Salix lends the capital for your solar installation at 0% interest. The loan repayment term is set so that annual repayments equal the modelled energy savings — making the project cash-flow neutral from commissioning. For a school borrowing £280,000 to install a 200 kWp solar system saving £42,000/year in energy costs, Salix would set a 7-year repayment schedule at £40,000/year — the school effectively pays for the installation entirely from energy bill savings.

What does a Salix loan application require?

A Salix BAU application requires: (1) a detailed energy assessment showing baseline consumption and modelled savings post-installation; (2) quotes from at least two MCS-certified installers; (3) a project description with technical specification; (4) financial information confirming the organisation can manage the repayment if energy savings fall short; (5) sign-off from the chief finance officer. The application form is submitted via the Salix online portal. We prepare all supporting documentation.

How long does a Salix loan application take?

Salix BAU loan decisions typically take 6–10 weeks from submission of a complete application. Complex applications (over £1m or involving multiple measures) may take longer. We submit complete, well-documented applications that reduce back-and-forth. Total timeline from initial survey to Salix loan approval is typically 12–16 weeks, running in parallel with DNO application for the same overall project timeline.

Can I combine Salix with other grants or tax reliefs?

Tax reliefs: public sector bodies do not pay corporation tax, so Full Expensing does not apply. However, 0% VAT applies to qualifying solar installations for public sector bodies — a significant saving. Other grants: UK Subsidy Control Act 2022 restricts combining two grants for the same project. However, Salix loans are loans not grants, so Salix BAU loans can potentially be combined with other eligible grant schemes — confirm with Salix and the other grant body on a case-by-case basis.

Free funding review

Salix Finance application — we handle everything

Eligibility check, energy modelling, application drafting, CFO pack and submission. Free initial review within one working day.

Start Funding Review Call 020 4525 6101

No obligation. We don't charge for grant scoping.