- PSDS Phase 4 (England)
- Closed 25 Nov 2024; delivery to 31 Mar 2028
- Salix England
- No open loan or grant (Aug 2026)
- Wales — WFP
- Open: 2.45% fixed, up to 100%
- Scotland — SPSEELS
- Open: 0%, up to 12-yr payback
PSDS vs Salix: which one fits your college in 2026?
As of August 2026 neither route is an open "apply now" window for an English college, so the historical comparison below needs a status check first. PSDS Phase 4 — the final phase, funded at £940m across 2025/26–2027/28 — took applications from 9 October to 25 November 2024, and on 12 June 2025 government confirmed no further investment beyond projects already awarded; those awards must complete by 31 March 2028. On the loan side, Salix's England pages now list grant schemes only, and the England Recycling Fund closed and moved to repayment on 31 March 2025. Interest-free or fixed-rate Salix loans remain open in Scotland and Wales.
| Your scenario | Capex / grant band | Timescale | Carbon per £ | Fit in 2026 |
|---|---|---|---|---|
| 1. Already hold a Phase 4 grant offer letter | FE college awards on the gov.uk list run £211k (Bedford College Group) to £4.91m (Middlesbrough College) | Deliver by 31 March 2028 | Grant carbon cost capped at £510/tCO2e lifetime; ≥12% recipient contribution | PSDS — protect the award, don't re-scope |
| 2. English college, standalone PV or PV + battery | Any | No PSDS or Salix England window open (Aug 2026) | No scoring gate applies | Neither today — reserves, borrowing, FECCA where its rules fit, or a PPA |
| 3. Welsh college | Up to 100% of project cost | Applications open; funding confirmations awaited (Salix note, 9 April 2026) | £350/tCO2e with a 10-year payback | Salix — Wales Funding Programme (2.45% fixed) |
| 4. Scottish college | Up to 100% of eligible compliant costs | Main loan open from 12 February 2026; the dedicated GB Energy solar pot within SEELS is closed — confirm PV eligibility with Salix Scotland | £305/tCO2e lifetime | Salix — Scottish SPSEELS (0%, up to 12-yr payback) |
Where a route still applies, the mechanics are covered in our guide to how the Salix loan route works for colleges and in delivering a PSDS Phase 4 award as an FE college. If you sit in scenario 2, the practical alternatives are reserves, borrowing or a power purchase agreement — and note Phase 4 PSDS only funded PV as a supporting measure in a building being heated by a PSDS-funded low-carbon heat source (earlier phases, notably Phase 1 in 2020, did fund standalone PV and LED).
Sources: Salix — Phase 4 PSDS; Salix, 12 June 2025; GOV.UK Phase 4 grant recipients (updated 4 December 2025: 207 organisations, 245 projects, £816.6m); England Recycling Fund; Wales Funding Programme; Scottish SEELS.
Historical comparison (how the two schemes worked while both ran)
| Dimension | Salix Decarbonisation Loan | PSDS Phase 4 |
|---|---|---|
| Type | Interest-free loan | 100% capital grant |
| Repayment | Yes — from energy savings (Scotland: up to 12 years; Wales: 10-year payback criterion) | No |
| Typical scale | Scotland: £5k minimum, no maximum; Wales: up to 100% of costs | FE awards on the Phase 4 recipient list: £211k–£4.91m |
| Application route (while open) | Assessed by the Salix technical team (2026 guidance: ~3 weeks for the open national loans) | Fixed application window (Phase 4: 9 Oct–25 Nov 2024) |
| Scoring threshold | None (energy savings must be auditable) | ~0.6-0.8 tCO2e per £100 of grant |
| Pure-PV scoring | Approved if savings are auditable | Usually below threshold — bundle required |
| Bundle requirements | None — can be PV only | Bundle with heat pump / fabric scores highest |
| Corporation board approval | Required | Required |
| FE eligibility | Yes (since Nov 2022 ONS reclass) | Yes (since Nov 2022 ONS reclass) |
| Multi-site portfolio | Yes — single bid supported | Yes — bundled bids supported |
| Year-1 net position | Cash-flow positive (savings > repayment) | Cash-flow positive (no repayment) |
| 25-year NPV | Strong (corp owns full benefit post-repayment) | Stronger (no repayment at all) |
| Application difficulty | Low-medium | High (competitive scoring) |
| Success rate | ~85% of well-prepared FE applications | ~25% of all bids; ~50% of bundled bids |
When to choose Salix
- Standalone solar project in Scotland or Wales (the open loan routes in 2026)
- Single-site or portfolio across same corp
- PV + battery combination
- Year 1 of Climate Action Plan delivery — fastest path to first install
- Corporation board prefers minimum capital exposure with clear repayment model
- Sustainability Lead has limited capacity for complex grant bid writing
When to choose PSDS Phase 4
- Solar bundled with heat decarbonisation (air-source heat pump replacing end-of-life gas boilers)
- Solar bundled with significant building fabric improvements
- Project capital cost above £400,000 — Salix cap getting tight
- Multi-campus group corporation programme delivering an existing Phase 4 award
- Year 2+ of Climate Action Plan — corporation has Year-1 data baseline supporting strong bid
- Corporation has bid-writing capacity and tolerance for competitive scoring uncertainty
When to combine both (most ambitious projects)
Many of the most ambitious FE solar programmes use both Salix and PSDS Phase 4 in parallel:
- PSDS Phase 4 covers the headline heat-and-PV bundle — typically £500,000-£2m in capital grant
- Salix Decarbonisation Loan covers incremental measures — battery storage extension, additional smaller-campus PV, EV charging integration
- MCA decarbonisation grant on top where applicable — typically £50,000-£250,000 layered on relevant campuses
- Combined funding stack delivers zero net capital cost to the corporation on a multi-million programme
A worked example — combined Salix + PSDS bid
An East Midlands group corp ran a £1.31m total programme across 8 campuses:
- Loan-funded share (historical England-era example): £917,000 over 10 years at £92,000/year (70% of total)
- PSDS Phase 4 capital grant: £393,000 (30% of total — paired with heat pump installs on 3 campuses)
- Annual energy savings: £305,000
- Net cash-flow positive year one: £213,000/year
- Year-11 onwards (post-Salix repayment): £305,000/year for remaining asset life