PSDS Phase 4 Deadline Guide for 2025-26 Solar Carport Applications

PSDS Phase 4 — the £1.4bn commitment

Public Sector Decarbonisation Scheme Phase 4 was announced by DESNZ (Department for Energy Security and Net Zero) in 2024, with £1.4bn allocated across 2024-28. Funding is administered by Salix Finance Ltd via the gov.uk/PSDS portal. Solar carports and EV charging infrastructure are explicitly named within the eligible scope per the 2024 scheme prospectus.

2025-26 application round timeline

Typical PSDS rounds open Q1 each year for delivery in the following financial year. Round timelines for 2025-26: Expression of Interest window: ~Q1 2025 (typically 8-12 weeks). Full application window: ~Q2 2025 (typically 6-8 weeks). Award decisions: Q3 2025. Delivery deadline: end of FY 2025-26 (March 2026). Some rounds offer 18-month delivery windows extending to FY 2026-27.

Eligible bodies

PSDS Phase 4 covers: NHS Trusts and Foundation Trusts; state schools and FE colleges (via Local Authority); HE institutions; local authorities and combined authorities; police, fire and rescue authorities; MoD non-operational estates; certain central government departments. Academies funded outside LA route should use DfE Condition Improvement Fund instead. Charities and private sector are not eligible.

Evidence pack required

PSDS applications require: (1) SBEM modelling of baseline energy and post-installation savings; (2) carbon abatement calculation per HM Treasury Green Book methodology; (3) technology compliance with Salix Compliant Technology List; (4) detailed project cost breakdown; (5) delivery timeline with critical milestones; (6) post-installation monitoring plan; (7) value-for-money case typically £/tCO2e abated (threshold £400/tCO2e for high-priority technologies; £200/tCO2e for standard).

Maximising approval probability

Five tactics that materially raise PSDS approval rates: (1) Apply early in the round — Salix budgets exhaust as the round progresses; (2) Pair solar with EV charging — combined projects score higher on multiple ScoringFramework criteria; (3) Demonstrate signed leadership sponsorship (Board, Cabinet, Executive) at application stage; (4) Use a Salix Trusted Partner installer; (5) Have a published Net Zero target / Carbon Reduction Plan referenced in the application.

What if Phase 4 closes before your project is ready

Three fallback routes: (1) Salix Recycling Fund — 0% interest loan, repayments from savings, eligible same year; (2) Welsh / Scottish public-sector loan schemes for bodies in those nations; (3) Wait for Phase 5 — expected announcement late 2026 or 2027 with similar quantum to Phase 4. Don't pause planning during the wait — pre-feasibility, design and DNO work can run in parallel.

How we run PSDS applications end-to-end

Process: (1) free initial feasibility identifies whether the project is PSDS-eligible and likely to score well; (2) full SBEM and carbon modelling pack drafted within 4-6 weeks; (3) application submitted via Salix portal; (4) we respond to Salix clarifications on your behalf; (5) at award, we deliver the project and run post-installation monitoring through Year 1. We are a Salix Trusted Partner with [our specific application success rate published in the next audit].