Multi-academy trust · 22 secondary schools · 3.2 MWp combined
3.2 MWp combined (avg 145 kWp per secondary) commercial solar PV installation with combined grant + tax relief stack delivering N/A (fully grant-funded) post-tax payback on £8,600,000 gross capex.
Anonymised composite case study
Names, dates and exact financial figures have been changed to preserve client confidentiality. Project structure, funding combinations, technical configuration, and order-of-magnitude figures are real and based on completed work. Full editorial disclosure on the about page.
Project snapshot
| Sector | Secondary education · multi-academy trust |
| Location | Midlands and South |
| System size | 3.2 MWp combined (avg 145 kWp per secondary) |
| Battery storage | None on solar; LED replacement integrated |
| Gross project capex | £8,600,000 |
| Grant value | £8.6m (PSDS Phase 3c — 100%) |
| Year-1 tax relief | N/A (trust — no CT liability) |
| Net effective cost | £0 |
| Annual savings/revenue | £695,000/year combined |
| Post-tax payback | N/A (fully grant-funded) |
| CO2 saving | 1,440 tCO2e/year combined programme |
| Year commissioned | 2025 |
Context
The multi-academy trust operates 22 secondary schools across the East Midlands, West Midlands and South East. Average school: 1,400 pupils, 6,500 m² floor area, 720,000 kWh/year electricity, 1.1m kWh/year gas. The trust's Sustainability Director identified PSDS Phase 3c as the strategic opportunity to address the trust's entire estate decarbonisation in a single capital programme.
The trust invested £320,000 in pre-application design across all 22 schools (£14,500 per school average) to deliver RIBA Stage 3 readiness ahead of the PSDS Phase 3c window opening in early 2024.
The challenge
Multi-academy trust constraints:
1. **Eligibility verification.** Different academy types within the trust had different PSDS eligibility — confirmed through Salix's academy eligibility list before application.
2. **Curriculum interruption avoidance.** All works had to fit within 13 weeks of summer break + ~6 weeks of Christmas and Easter breaks combined.
3. **Estate variation.** 22 schools with build dates ranging 1955-2018, mixed roof condition, mixed heating systems (gas boilers, oil boilers in 4 rural schools, district heat at 2).
4. **Tender scale.** £8.6m programme exceeded the high-value threshold requiring formal OJEU-equivalent tendering under PCR 2015.
5. **Governance.** Trust board approval for the application, plus individual academy governing body approvals for each school's participation.
Funding approach
The trust structured the application as a single combined PSDS bid covering all 22 schools with three integrated interventions per school:
**Solar PV:** 145 kWp average per school. Total programme 3.2 MWp. **Heat pumps:** ASHP cascade replacing gas boilers at 18 schools. Oil boilers replaced at 4 rural schools. **Insulation + LED:** Fabric upgrade + LED retrofit at all 22 schools. **BMS:** Carbon-reporting capable BMS upgrade at all 22 schools (Salix-funded element).
Funding stack:
- **PSDS Phase 3c grant:** £8.6m (100% of qualifying capex) - **Salix Recycling Fund:** £420,000 at 0% over 8 years (BMS upgrades not PSDS-eligible) - **Internal trust capital:** £180,000 for unfunded Listed Building Consent costs
Phased delivery:
- **Wave 1 (Summer 2024):** 8 modern schools. 1.1 MWp combined solar. - **Wave 2 (Christmas 2024-Easter 2025):** 6 mid-age schools. 850 kWp combined. - **Wave 3 (Summer 2025):** 8 remaining schools. 1.25 MWp combined.
Outcome & performance
All 3 waves completed by Q4 2025, slightly ahead of the 18-month PSDS delivery window. Combined performance:
- **Annual solar generation:** 3.04m kWh across all 22 schools - **Combined self-consumption:** 52% (term-time daytime weighted) - **Annual electricity import reduction:** £580,000/year - **Heat pump operating saving:** £85,000/year (electricity for heat displacement vs gas) - **LED operating saving:** £30,000/year combined - **SEG export revenue:** £62,000/year (high during school holidays) - **Combined annual savings:** £757,000/year (gross); £695,000 (after operating cost adjustments) - **CO2 saving:** 1,440 tCO2e/year (solar 305 + heat pump 980 + LED 155 combined)
The trust's 2025 annual report cites the programme as the largest single contributor to the trust's decarbonisation pathway. The Sustainability Director is now planning a follow-on Phase 4 PSDS application for sixth-form centres and ancillary buildings not in the original programme.
Lessons learned
- Multi-academy trust solar requires multi-school application coordination — but the per-school cost is materially lower than individual applications.
- Integrated solar + heat pump + insulation + LED scores materially better in PSDS than solar-only — the £320k pre-application investment paid back many times over.
- Phased delivery across multiple school break windows is the only practical option. 6-8 schools per summer is the realistic delivery rate.
- Older oil-heated rural schools have particularly strong heat pump retrofit business cases — IETF doesn't apply to schools but PSDS covers oil-to-heat-pump conversions generously.
- PSDS Phase 3c was £230m total budget; Phase 4 is expected similar. Be application-ready before window opens — typical timeline 12-18 months.
Could a similar approach work for your business?
Free 60-second eligibility check tells you exactly which grants, tax reliefs and finance routes apply to your specific business.
Free eligibility check Read more case studies