A 250 kW warehouse solar system is ideal for mid-size warehouse buildings, fulfilment centres, cross-dock parcel hubs, and larger last-mile depots. With 460 panels covering 1,500-2,200 sqm of roof, the system fits 60,000-100,000 sqft warehouses. Per-kW cost drops vs 100 kW (project mobilisation amortised over more kW). 4.5-6 year payback for most operational profiles.
Typical 250 kW system specification
Capacity: 250 kW. Panels: 460 modules at 540W. Roof area: 1,500-2,200 sqm usable. Inverters: 4-6 string inverters. Annual generation: 230,000 kWh (UK average). Capex: £200-250k installed. AIA tax shield: £50-62k year 1. Payback: 4.5-6 years simple, 3.5-5 years after-tax.
When 250 kW is the right size
Buildings 60,000-100,000 sqft with daytime baseload 200-300 kW. Mid-size fulfilment centres. Cross-dock parcel hubs (Royal Mail, Evri, DPD network). Larger last-mile depots with EV van fleet. Mid-range manufacturing facilities (engineering, food production, plastics).
Economics worked example
250 kW install on a 75,000 sqft fulfilment centre: capex £225k. AIA tax shield year 1: £56k. Annual generation 230,000 kWh. At 85% self-consumption and 22p/kWh grid retail: £43k/yr saving. SEG export on residual: £4k/yr. Total annual benefit £47k. Simple payback 4.8 years. After-tax cash payback 3.6 years. 25-year IRR 21%.
Common questions about 250 kw system
What warehouse types suit 250 kW?
Mid-size fulfilment centres, cross-dock parcel hubs, larger last-mile depots, mid-range manufacturing. Buildings 60,000-100,000 sqft with daytime baseload 200-300 kW.
How does 250 kW compare to 500 kW economics?
Per-kW capex slightly higher at 250 kW (£800-1,000/kW) than 500 kW (£750-900/kW) due to project mobilisation amortisation. But absolute capex £200-250k vs £400k+ — 250 kW often the right size when capex constraints matter. Payback similar (4.5-6 years).