Salix Finance for commercial solar UK 2026

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 worked example — 500 kWp NHS trust / council leisure centre

A second body type, to show the same mechanism at larger scale. This is an indicative model for a high-daytime-load public building — an acute hospital wing, a council leisure centre or a depot — where self-consumption is high and the economics are strong.

• Site: NHS trust energy centre / council leisure centre, high daytime electrical load
• System size: 500 kWp rooftop + canopy solar (no battery — load soaks generation directly)
• Gross installation cost: £360,000 at £720/kWp turnkey
• 0% VAT applied: quotes issued at 0% VAT — no VAT to add
• Modelled annual energy saving: £74,000 (mostly displaced grid import at ~80% self-consumption)
• Salix loan term: 6 years at £60,000/year (≤ modelled saving — passes the cash-flow-neutral test)
• Net cash impact year 1–6: £74,000 saving − £60,000 repayment = +£14,000/year positive cash flow
• Net cash impact year 7–25: £74,000/year saving, loan repaid — £1.4m+ cumulative 25-year benefit

What Salix Finance actually is — and why the 0% is real

Salix Finance Ltd is a government-owned, not-for-profit company set up in 2004 to accelerate energy efficiency across the UK public sector. It is funded by central government — principally the Department for Energy Security and Net Zero, with historic funding lines from the Department for Education for schools and from the devolved administrations in Scotland and Wales. Because the capital comes from public funds rather than commercial lenders, Salix lends at a genuine 0% — not a discounted or subsidised rate dressed up as zero. Its remit is narrow and useful: it only funds measures that demonstrably save energy — solar PV, heat pumps, LED lighting, building management systems (BMS) and controls, battery storage and fabric improvements — for organisations that don\'t pay corporation tax and therefore can\'t use the Full Expensing capital allowances private firms rely on. That public-sector-only eligibility is the single biggest filter: if you\'re an NHS trust, council, school, academy trust, university, FE college, housing association or emergency service, you\'re in scope; if you\'re a private business, you are not (look at commercial solar funding routes instead).

How to apply for Salix Finance funding — step by step

The Salix BAU loan is assessed on evidence, not on persuasion. The application succeeds or fails on whether the numbers show the project pays for itself from energy savings within the loan term. Here is the process in the order it actually runs:

1. Eligibility check. Confirm your organisation is a qualifying public sector body and the project clears the £50,000 minimum. This is fast — usually a day — and worth doing first because it determines which Salix product (BAU loan, or a net-zero fund if one is in round) you target.
2. Establish the energy baseline. Salix needs to know what you spend now. Pull at least 12 months of electricity (and gas, where relevant) consumption — half-hourly data is ideal. This baseline is the denominator for every saving claim that follows.
3. Model the saving. For solar this means a generation estimate (annual kWh for the proposed kWp), a self-consumption profile (how much you use on-site versus export), and the resulting £ saving from displaced grid import plus SEG export income. The credibility of this model is what the assessor scrutinises hardest.
4. Specify and price the project. Produce a technical specification — array size, panel and inverter detail, any co-located battery — and obtain quotes from at least two MCS-certified installers so Salix can confirm the cost is reasonable.
5. Test against the assessment criteria. Three gates: the modelled annual repayment must be no greater than the modelled annual energy saving (the cash-flow-neutral test), the payback must fall within the allowable loan term (typically 5-12 years), and the cost-per-tonne of carbon saved must be acceptable. If the solar-only payback is too long, bundling LED, controls or a heat pump usually pulls the blended economics inside the threshold.
6. Get CFO sign-off and submit. The chief finance officer confirms the body can service repayments if savings underperform. The completed application — energy model, installer quotes, technical spec, financials and carbon estimate — is then lodged through the Salix online portal.

The defining feature of the mechanism is repayment from savings: Salix sizes the loan term so that each year\'s repayment is covered by that year\'s energy saving, which is why a well-modelled project is cash-flow neutral or positive from the day it\'s commissioned. Decisions on a complete BAU application typically take 6-10 weeks; larger or multi-measure projects can take longer. Because scheme rounds and net-zero fund windows open and close, always confirm the current round and product status with Salix (or with us) before you build the application — the BAU loan fund is rolling, but specific grant pots are not.