Solar Plus Battery vs Battery-Only — UK Factory 2026
Battery-only deals (DSR, Capacity Market) work for pure peak-shaving. Solar plus battery wins for any factory drawing more than 800 MWh/year.
When battery-only beats solar plus battery
Battery-only systems make commercial sense for sites with three specific characteristics:
- High DUoS / triad exposure — sites paying >£30k/year of network charges
- Constrained roof or no suitable solar substrate
- Active in flexibility markets — Dynamic Containment, Capacity Market, DSR participation generates 8–15 p/kWh of additional revenue beyond grid arbitrage
In these cases a 500 kWh-2 MWh battery alone, charging from cheap overnight grid and discharging at peak, can deliver 6–9 year payback — respectable but slower than the 3–5 year payback typical for solar.
When solar plus battery wins decisively
For factories drawing more than ~800 MWh/year, solar plus battery beats battery-only across every metric:
- Capex efficiency — solar at £700/kWp delivers ~10x more annual kWh per £ than batteries alone
- Self-consumption arbitrage — solar generates at retail tariff (28 p/kWh saved), exports at SEG (4–12 p/kWh). Battery alone arbitrages cheap-rate (8 p) to peak (35 p) — less spread
- Combined revenue stack — solar self-consumption + battery flexibility revenue + SEG export = 3 income streams, not 1
- Faster payback — combined systems pay back in 4–6 years vs 6–9 for battery-only
Solar Plus Battery vs Battery-Only — UK Factory 2026 — FAQs
What changes if my factory is in Scotland or Wales?
Mainly DNO connection timelines (faster in Scotland) and regional support (such as the Welsh Government Energy Efficiency Loan; Scotland's Industrial Energy Transformation Fund has closed all its calls). Core economics unchanged.
Is the answer different for a tenant vs owner-occupier?
See our dedicated tenant vs landlord guide for full ownership-model analysis.
How do I get an honest comparison for my specific site?
Submit a quote request with your annual electricity spend and roof type, then ask the installers who respond to model both options against your half-hourly meter data and share the side-by-side NPV/IRR/payback.
Want a side-by-side comparison for your site?
Request matched quotes and ask installers to model the case against your actual half-hourly meter data, not industry averages.
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