Office Solar Case Study
London serviced office — 220 kWp + workplace EV charging
London serviced office — 220 kWp + workplace EV charging
A serviced-office operator with a 4,200 sqm Shoreditch building wanted to differentiate its premium-tier suites from coworking competitors. We designed a 220 kWp PV install on the rooftop terrace and basement-car-park solar carport, plus 16 × 22 kW workplace EV chargers funded through OZEV’s Workplace Charging Scheme grant (£350/socket).
The numbers
| Metric | Value |
|---|---|
| System size | 220 kWp PV + 16 × 22 kW EV chargers |
| Panel count | 410 |
| Annual generation | 204,000 kWh/year |
| Annual saving | £68,000/year (PV) + £24,000 (EV revenue) |
| Simple payback | 5.8 years |
| Annual CO₂ saved | 47 tonnes |
| EPC uplift | C → A (12-point gain) |
| Completion | Q2 2026 |
Project approach
The starting point on this project, as with every commercial office install we deliver, was the customer’s half-hourly meter data. Without it, sizing decisions are guesswork — the difference between a 70% self-consumption design and a 30% one usually comes down to load profile rather than roof area or panel choice. We pulled twelve months of half-hourly consumption from the customer’s DNO, ran the demand profile against PVSyst yield models for the building’s specific latitude, roof pitch, and shading characteristics, and modelled three scenarios: PV-only at 60% coverage, PV-only at 80% coverage, and PV plus battery at 95% coverage.
The scenario that won on NPV-over-25-years was the middle option — PV-only sized to deliver around 80% of annual demand, accepting a slight summer-export tail under SEG rather than over-sizing battery for marginal additional self-consumption. The economics of battery storage continue to shift as cell prices fall and capacity-market revenues rise, but for this specific building’s load shape and electricity tariff structure, the unbatteried design produced the best 25-year IRR.
Roof, structural, and electrical
The roof was assessed for structural loading per BS EN 1991-1-1 (dead loads) and BS EN 1991-1-4 (wind loads). Ballasted east-west arrays were specified to preserve membrane warranty and avoid roof penetration. Two string inverters were sized at 110% of array DC capacity to capture clipping-edge gains during cloudy summer peaks. Cable routes ran via existing rooftop plant rooms to the main switchroom, avoiding occupied office floors entirely.
Grid connection went via G99 with the local DNO — application submitted six months ahead of planned install date, with full export and import limits agreed at the connection offer stage. Commissioning followed IEC 62446 with full string-level performance documentation handed to the customer’s facilities team alongside an O&M manual covering quarterly visual inspection, annual cleaning, and 5-year inverter warranty management.
Compliance, EPC and reporting
The system was specified to MCS Commercial standards with NICEIC electrical certification. RECC-compliant customer documentation was provided. The EPC was re-rated after commissioning with the install captured under SAP 10.2 methodology — delivering the C → A (12-point gain) uplift recorded above and locking the building’s MEES 2030 compliance position.
For the customer’s Scope 2 emissions reporting, we provided a disclosure pack containing location-based and market-based emissions calculations, REGO certificate handling guidance, SECR-ready narrative for the annual report, and CDP Climate Change response text pre-populated for solar-related questions.
What the customer said
“We sold the ‘powered by sunshine’ message in every tour. Occupancy on our top-floor premium suites moved from 78% to 96% within six months.”
Could your office building deliver similar results?
The economics on this case study aren’t unusual for a well-designed office solar install in 2026 — payback inside 7 years, double-digit IRR over 25 years, meaningful EPC uplift, and Scope 2 reduction documented to FTSE-tenant audit standards. What varies between offices is the specific load shape, roof area, electrical infrastructure age, and tenancy structure.
The fastest way to understand your specific economics is a free desk feasibility study. Send us half-hourly meter data and a roof plan, and we’ll model your building specifically within 7 working days.