1.1 MW Solar + Battery — Yorkshire Land-Based College, Blended Salix + PSDS + DEFRA Stack
- System size
- 1,100 kW
- Annual saving
- £262,000
- Payback
- 4.6 years
- Location
- Yorkshire, North of England
Scenario
A specialist land-based college in north Yorkshire, operating across a 600-acre estate combining an academic teaching block, an active commercial dairy unit, a halls-of-residence block for 220 residential students, equine yards, agricultural workshops, and a working farm shop. Enrolment runs to roughly 1,800 full-time learners spanning Level 2 land-based provision, T-Level Agriculture, foundation degrees in partnership with a regional university, and a substantial apprenticeship cohort.
The college’s energy bill structure is fundamentally different from a city-centre FE college. The 2024-25 combined bill ran to £880,000 — roughly half consumed in the academic and halls blocks, roughly a third in the dairy operation (refrigeration, milking parlour, ventilation, lighting), and the balance across workshops, yards, and the farm shop. The load profile is 24/7 not 08:00-17:00 — the dairy runs continuously, the halls carry an overnight base load, and the workshops cycle hard during teaching hours.
The Principal had been clear with the corporation board that any decarbonisation programme had to address all three load centres credibly, and that the funding strategy had to recognise the college’s hybrid commercial-and-educational character. A single-source funding stack (Salix alone, or PSDS alone) would have struggled — the dairy is a commercial revenue centre and the halls carry residential-style load — so the bid architecture had to blend across three funders.
This case study is an illustrative composite based on representative land-based college engagements. Specific identifying details are anonymised.
What we delivered
Total programme: 1,100 kW solar across three load centres plus 400 kWh of battery storage, sequenced for phased install across two summer windows and one Christmas mobilisation.
- Main teaching block + halls cluster: 420 kW (770 × 545 W panels across the main academic roof, the LRC, and two halls-of-residence blocks. Mix of membrane and standing-seam roofs. Three string inverters in the main plant room. 200 kWh battery storage to shift academic-day generation into the halls overnight load.)
- Commercial dairy unit: 480 kW (880 × 545 W panels across the milking parlour roof, two cubicle sheds and the silage clamp roof. Standing-seam clamp-mount, no roof penetrations on the dairy buildings. Two string inverters in the dairy plant room. 200 kWh battery storage to ride the milking-cycle peak loads through the early-morning and late-afternoon parlour windows.)
- Workshops + farm shop cluster: 200 kW (368 × 545 W panels across the agricultural workshops and the farm-shop roof. Single string inverter in the workshop plant room. No battery — daytime workshop and shop load consumes generation directly.)
- Live-generation and battery-state dashboard in main reception, dairy plant room, and the farm shop, with a public-facing summary screen in the farm-shop café visible to retail customers
DBS-cleared install crews across all three clusters. KCSIE 2025 safeguarding induction by the estates director at every cluster mobilisation. Dedicated dairy biosecurity protocol agreed with the dairy unit manager before any contractor access to the parlour roofs.
Funding stack — blended Salix + PSDS Phase 4 + DEFRA
The architecture of this bid is the key takeaway. No single funder covered the whole capex; three funders each carried the element they were structurally aligned with:
- PSDS Phase 4 grant: £490,000 covering the academic + halls cluster (420 kW solar + 200 kWh battery). PSDS Phase 4 is built for public-sector heat and power decarbonisation on the educational estate — and the integrated solar+battery+future-heat-pump argument carried the bid through panel
- Salix Decarbonisation Loan: £170,000 covering the workshops + farm-shop cluster (200 kW). Salix accepts FE college applications on the workshop and ancillary estate provided the energy-savings case is auditable
- DEFRA Improving Farm Productivity grant + Farming Investment Fund stack: £290,000 covering 50% of the commercial dairy cluster (480 kW + 200 kWh battery). The dairy unit is a working commercial enterprise, and DEFRA’s productivity grant covers solar-and-battery on commercial agricultural buildings at up to 25% with the FIF top-up taking it to 50% on bundled productivity-and-decarbonisation bids. The dairy unit holds a separate trading entity which made the DEFRA application clean — the academic side could not have applied for DEFRA money on academic buildings
- Commercial dairy unit residual self-fund: £290,000 (the residual 50% of the dairy cluster) covered from the dairy operation’s commercial reserves with internal payback inside 3.8 years
- Total programme capital cost: £1.24 million at £1,127/kW (the layered funding architecture and the dairy-specific install requirements lifted the unit cost vs a single-funder educational-only project; without the dairy element the academic-and-workshops-only unit rate would have come in at £935/kW)
- Modelled annual energy savings: £262,000 combined across the three clusters
- Year-one net cash position: £214,000 positive (savings minus Salix repayment; PSDS and DEFRA are non-repayable grants)
- Total 25-year nominal benefit: £6.8m (real-terms model across the combined estate)
The three applications were prepared in parallel by a single bid team and submitted within a six-week window. All three funders accepted on first submission. The corporation board approved the blended package at the November 2025 board meeting, recorded under a single Climate Action Plan agenda item with three separate funding-line entries.
Programme phasing
Christmas 2025 mobilisation (build window 0):
- Procurement lock-in, structural surveys across all three clusters, DNO scoping, dairy biosecurity protocol sign-off
Summer 2026 (build window 1):
- Academic + halls cluster — 8 weeks scaffold + install + battery commissioning
- Workshops + farm shop cluster — 4 weeks install
Summer 2027 (build window 2):
- Dairy unit cluster — 10 weeks install (programmed around the milking schedule; no parlour-roof work between 04:00-08:00 or 14:30-18:30 milking windows)
No academic cohort lost more than two days of timetabled building access. The dairy unit operated through the install at full milking capacity. The phasing was scoped against both the academic calendar and the dairy operation’s quarterly milk-production cycle before contract sign.
Compliance and DNO
- Three parallel G99 DNO applications across one DNO (Northern Powergrid) but three separate metering points. All three accepted inside 18 weeks; the dairy cluster required an export-limiter setting at 350 kW to clear the local rural network constraint
- Asbestos R&D survey on the pre-2000 academic block and the older dairy cubicle sheds; one Type 3 enclosed protocol penetration on the academic block
- Structural engineer survey on every roof slope across the three clusters; the silage clamp roof required a steel-truss strengthening package costed into the dairy-cluster capex
- Dairy biosecurity protocol — agreed contractor entry routes, wash-down stations, dedicated boot/overall stores, no cross-traffic between dairy and academic clusters during install
- KCSIE 2025 safeguarding induction by the estates director at every contractor mobilisation across the academic and halls cluster
- ESFA Post-16 Audit Code: Salix and PSDS drawdowns lodged as auditable workpapers; DEFRA grant drawdown lodged separately under the dairy trading entity’s audit framework; corporation board minute formally records all three funding lines
Outcomes
- Year-one actual generation: 7% above design model across the three clusters (weighted average; the dairy cluster overperformed at 9% above model on the south-aspect parlour roof)
- Year-one actual energy savings: £280,000 versus modelled £262,000 (+6.9%)
- Battery self-consumption uplift: academic+halls cluster lifted from 68% (PV-only) to 94% with the 200 kWh battery active; dairy cluster lifted from 79% (PV-only) to 96% with the 200 kWh battery active capturing the milking-window peaks
- EAUC Scorecard: moved the college from “Silver” to “Gold” on the Operations and Estates module and unlocked a “Distinction” categorisation on the Curriculum module driven by T-Level Agriculture integration
- AoC Climate Action Plan reporting integration — all three clusters’ generation and avoided-emissions feed into the corporation’s quarterly KPI pack
- T-Level Agriculture cohort produced a year-long sustainability documentary on the install as their synoptic project, used as part of the college’s autumn 2026 open evenings and submitted as a regional T-Level showcase entry
- Farm shop retail uplift — the public-facing dashboard in the café was credited (in the marketing team’s quarterly review) with measurable footfall from sustainability-conscious local retail customers
- DEFRA case study placement — featured in the 2027 DEFRA Improving Farm Productivity progress report as a flagship blended-bid example for the land-based education sector
- Phase 2 scoping opened in autumn 2026 around a 350 kW agri-PV canopy over an equine all-weather arena, with all three funders re-engaged at the feasibility stage
What the Sustainability Lead said
“Land-based colleges that go to a single funder will land somewhere between half and two-thirds of what they actually need. The grant architecture isn’t built for our hybrid estate — half educational, half commercial — and the funders know it. We won this programme by treating the funding stack as an architecture problem the same way we treated the engineering: three load centres, three funders, three bid threads running in parallel against a single corporation Climate Action Plan. That’s the playbook for any land-based or specialist college with a commercial side to its estate.”