Solar vs Grid
Commercial Solar vs Grid Electricity Cost UK 2026
UK commercial solar generates electricity at £0.06–£0.08/kWh (lifetime levelised cost). Grid imports cost £0.27–£0.35/kWh. The spread is the source of the financial case for solar.
£0.06–£0.08
Solar £/kWh
£0.27–£0.35
Grid £/kWh
4–5×
Solar/grid spread
£600k+
25-yr 100kW saving
The single most important number for UK commercial solar is the spread between the levelised cost of solar electricity (£0.06–£0.08/kWh over 25 years) and the cost of grid electricity (£0.27–£0.35/kWh in 2026). Every kWh of solar generated and self-consumed displaces grid at this much higher price. That spread is what drives 3–5 year paybacks.
The Levelised Cost of Solar (LCOE)
Levelised cost = total project cost ÷ total kWh generated over 25 years. For UK commercial solar in 2026:
- 100kW system: £100k capex ÷ 2.4M kWh lifetime = £0.042/kWh raw LCOE; £0.06/kWh including financing + O&M
- 500kW system: £450k capex ÷ 12M kWh = £0.038/kWh raw; £0.05/kWh all-in
- 1MW system: £900k capex ÷ 24M kWh = £0.038/kWh raw; £0.05/kWh all-in
Solar LCOE is the lowest of any UK electricity generation source in 2026 — below new gas, new nuclear, new wind, and obviously below grid retail.
UK Grid Electricity Cost — 2026 Reality
- Wholesale electricity: ~£0.10–£0.13/kWh (volatile)
- Network charges (DUoS, TNUoS): ~£0.05–£0.08/kWh
- BSUoS, RO, FiT, AAHEDC, Capacity Market: ~£0.06–£0.08/kWh
- Supplier margin and overhead: ~£0.02–£0.04/kWh
- VAT (where applicable): 20% on top
- Total commercial retail price: ~£0.27–£0.35/kWh in May 2026
What 25 Years of the Spread Looks Like
For a 100kW commercial solar system over 25 years:
- Lifetime kWh generated: ~2.4 million
- Lifetime kWh self-consumed (80%): ~1.92 million
- Average grid price displaced (with 1.5% inflation): ~£0.36/kWh average across the 25 years
- Average solar cost paid: ~£0.06/kWh
- Net saving per kWh: ~£0.30
- Lifetime saving: ~£575,000
- Lifetime export saving (export at SEG ~£0.15/kWh): ~£72,000
- Total lifetime saving: ~£650,000+
The Direction of Travel — Why the Spread Will Widen
- Grid electricity prices forecast to rise: ageing infrastructure, network reinforcement costs, capacity market demand, gas-set marginal pricing. National Grid ESO base case forecasts 2–4% real annual rise through 2035.
- Solar capex falling: tier-1 panel + inverter prices continue to drop ~5%/year. New installs in 2030 will have lower LCOE than 2026 installs.
- Battery costs falling fast: battery LCOE down ~15%/year. Solar + battery enables higher self-consumption ratios.
What This Means for Your Business Case
- Every kWh of solar self-consumed is worth ~£0.25 net (today's prices, today's solar cost).
- The spread is locked in — if grid prices rise, the saving rises proportionally.
- Solar cost is fixed at install (panels + inverter cost is paid). Grid price is volatile and rising.
- Solar is a hedge against grid price volatility — particularly valuable in a UK energy market where wholesale prices have tripled in 4 years.
Frequently Asked Questions
What does commercial solar cost per kWh?
UK commercial solar levelised cost (LCOE) is £0.06–£0.08/kWh over 25 years (including financing and O&M). Grid retail prices for commercial buyers are £0.27–£0.35/kWh — typically 4–5× higher.
Why is grid electricity so much more expensive than solar?
Grid retail electricity bundles wholesale generation, network charges (DUoS, TNUoS), policy levies (BSUoS, RO, FiT), supplier margin, and VAT. Solar (self-generated, behind-the-meter) avoids the network and policy components and the supplier margin.
Will grid prices keep rising?
National Grid ESO base case forecasts 2–4% real annual rise in commercial electricity through 2035. Drivers: ageing infrastructure, network reinforcement, capacity market, gas-set marginal pricing in winter.
How does solar protect against grid price volatility?
Solar capex is paid at install. Once paid, the marginal cost of generated electricity is near-zero. Grid price volatility doesn't affect solar generation cost — providing a hedge against future grid price spikes.
What is the lifetime saving on a 100kW commercial solar system?
~£600,000–£700,000 over 25 years for a typical UK 100kW system, assuming 80% self-consumption and 1.5% real grid price inflation.
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