640 kW Multi-Campus Solar — London FE Group Corporation, GLA + Salix Stack
- System size
- 640 kW
- Annual saving
- £158,000
- Payback
- 4.9 years
- Location
- Greater London
Scenario
A Greater London FE group corporation formed by a 2019 merger now operates across three campuses spanning two boroughs — a flagship technical and digital campus in inner east London, a construction and engineering campus on a former industrial site in outer east London, and a creative industries campus in inner south London. Combined enrolment runs to roughly 9,400 16-19 learners plus a sizeable adult and apprenticeship cohort.
The corporation’s 2024-25 group electricity bill was £1.42 million. London electricity unit rates have run consistently above the national average, and the corporation’s 2025 strategic plan committed the group to a 60% scope-1+2 emissions reduction against the 2019-20 baseline by 2030 — more aggressive than the AoC Climate Action Roadmap minimum and explicitly designed to dovetail with the GLA Mayor’s net-zero-by-2030 framework.
The estates director and incoming Sustainability Lead — promoted internally from a campus facilities manager role — set out a Climate Action Plan to corporation in autumn 2025 with rooftop solar as the lead intervention across all three sites. The brief from the corporation board: bring in external capital, sequence the build around teaching, and use the scale of the programme to drive unit cost below £900/kW.
This case study is an illustrative composite built from published scheme terms and 2026 London FE group corporation benchmark costs. It does not describe a single real installation.
The modelled design
Total programme: 640 kW across three campuses, designed as a single portfolio bid with phased installation over two summer windows.
- Technical and digital campus (inner east London): 290 kW (532 × 545 W panels across three connected membrane-roof blocks, 12-14° tilt, two string inverters, 120 kWh battery storage in main plant room to time-shift apprentice evening-class load)
- Construction and engineering campus (outer east London): 240 kW (440 × 545 W panels across the main workshop and adjacent classroom block, mostly south-aspect, two string inverters, no battery — daytime workshop load consumes generation directly)
- Creative industries campus (inner south London): 110 kW (200 × 545 W panels across the production-studio block, single string inverter; site constrained by heritage-area planning consent on the front elevation, all panels concealed to rear roof slopes)
Single corporation-wide programme management. DBS-cleared install crews across all three campuses. KCSIE 2025 safeguarding induction at every campus by the campus principal or nominated deputy before any contractor access.
Funding stack — blended GLA + Salix
The unlock on this programme was layering a GLA-backed grant against the Salix Decarbonisation Loan for the residual:
- Greater London Authority decarbonisation grant: £190,000 (30% of capex), drawn from the GLA’s RE:FIT and Local Energy Accelerator funding streams aligned with London Plan Policy SI 2 and the Mayor’s Solar Action Plan
- Salix Decarbonisation Loan: £435,000 (residual 70%), 8-year term, £54,375 annual repayment
- Total capital cost: £625,000 at £977/kW (the heritage-consent constraint at the creative campus added cost vs the portfolio benchmark; without that constraint unit cost would have come in around £915/kW)
- Modelled annual energy savings: £158,000
- Year-one net cash position: £103,625 positive (savings minus Salix repayment, no GLA grant repayment)
- Total 25-year nominal benefit: £2.7m (real-terms model)
The GLA grant application was led by the corporation’s Sustainability Lead with structural support from the group’s deputy CFO; the Salix bid was a single portfolio submission covering the residual. Both funders accepted on first submission inside a combined 14-week window. The corporation board approved the layered package in a single November 2025 minute.
Programme phasing
Summer 2026 (build window 1):
- Technical and digital campus — 8 weeks scaffold + install + commissioning, including battery integration; commissioned 14 August
- Creative industries campus — 4 weeks scaffold + install + commissioning; the planning-consent restriction added two design iterations but no programme slippage
Summer 2027 (build window 2):
- Construction and engineering campus — 8 weeks scaffold + install + commissioning across the workshop and classroom blocks; sequenced to avoid the August T-Level Construction synoptic project window
No teaching cohort across the three campuses lost more than three days of timetabled access to a building during install. The phasing was scoped against the corporation’s combined academic calendar before contract sign and locked in the programme baseline.
Compliance and DNO
- Three parallel G99 DNO applications across two different DNOs (UK Power Networks east London, UK Power Networks south London — same DNO, two regional design teams). All three accepted inside 16 weeks; the construction campus required a minor export-limiter setting at 200 kW to clear the local network constraint
- Asbestos R&D survey on the pre-2000 technical and creative campus buildings; Type 3 enclosed protocols needed for two roof penetrations on the inner east campus
- Structural engineer survey on every roof slope across the three campuses
- Heritage area planning consent for the creative campus secured at pre-app stage and lodged formally six weeks ahead of design lock
- KCSIE 2025 safeguarding induction by the campus principal at each campus before any contractor access
- ESFA Post-16 Audit Code: Salix energy savings calculation and GLA grant drawdown both lodged as auditable workpapers; corporation board minute formally records both elements of the funding stack
Outcomes
- Year-one actual generation: 6% above design model across the three campuses (weighted average)
- Year-one actual energy savings: £167,500 versus modelled £158,000 (+6.0%)
- Battery self-consumption uplift at the technical campus: lifted self-consumption from 71% (PV-only) to 94% with the 120 kWh battery active, capturing the inner-London peak rate spread
- GLA case study placement — featured in the GLA’s 2027 RE:FIT progress report as a flagship multi-site FE programme
- EAUC Scorecard: moved the group from “Silver” to “Gold” on the Operations and Estates module on the post-install re-submission
- AoC Climate Action Plan reporting integration — generation and avoided-emissions feed live into the corporation’s quarterly KPI pack across all three campuses
- Phase 2 approved November 2026: additional 180 kW at the construction campus on roofs not in the original feasibility, plus integration planning for a 200 kW carport canopy at the technical campus staff/visitor car park
What the Sustainability Lead said
“Going to corporation with a 100% Salix-funded number works for a single college. Going with a 30% GLA grant on top of that completely changes the conversation — it lifted us inside the corporation’s five-year hurdle rate and it positioned the programme inside the Mayor’s net-zero framework, which mattered for our local authority skills-funding relationships. The lesson is to scope the funding stack at the same time as the engineering, not after.”