If your business already has rooftop solar, the single biggest value left on the table is the surplus you export at a low Smart Export Guarantee rate and then buy back hours later at full retail. A battery closes that gap. It captures the daytime surplus and releases it into the evening and early-morning load, lifting self-consumption toward 80% or more and capturing the spread between import and export prices.
How battery plus existing solar (self-consumption) saves a business money
The battery is sized to your solar SURPLUS profile, not the headline PV kilowatts. We pull twelve months of half-hourly generation and consumption data, measure how much you currently spill, and size the battery to store the recoverable portion. On top of the self-consumption gain, the same battery shaves your red-band DUoS peaks, so it earns from two streams at once.
We build the case for battery plus existing solar (self-consumption) on controllable savings, cutting the red DUoS band, trimming demand and capacity charges, and lifting solar self-consumption where panels exist, rather than on volatile grid-services income, which we count only as a bonus. Every figure comes from your half-hourly data and is shared in full.
What this looks like on your site
- Stores daytime solar surplus for evening and early-morning use, lifting self-consumption from 40-60% to 80%+
- Stops you exporting at a low SEG rate and re-importing hours later at full retail
- Sized to your solar SURPLUS profile from half-hourly data, not your headline PV kW
- Best payback where the load is daytime-light but evening or overnight heavy
Who it suits
Best where the load is daytime-light but evening or overnight heavy: offices that empty at 5pm, single-shift manufacturers, and sites with a large array but a modest daytime base load.
Typical battery plus existing solar (self-consumption) system
| Power / capacity | 50 kW / 100 kWh - 500 kW / 1,000 kWh |
| Project value | £55,000-£550,000 |
| Payback | 6 years |
| Annual CO₂ saved | 10-120 tonnes |
| Capital allowances | 100% AIA to £1m, then 50% FYA |
Indicative. Your figure is modelled from twelve months of half-hourly meter data. See cost and payback by size.
Compliance and safety
G99 application where combined generation and storage export exceeds the DNO limit; G100 export limitation commonly used to stay within agreed export capacity. MCS-certified storage install. Battery and inverter to BS EN 62619 cell safety and BS EN/IEC 62933 system safety.
Every system is designed to PAS 63100:2024 fire-safety principles with lithium-iron-phosphate (LFP) cells, BS EN 62619 cell safety, and BS EN/IEC 62933 system safety, with your insurer engaged up front.
No obligation, no phone hard-sell
There is no obligation and no phone hard-sell. We model the payback for battery plus existing solar (self-consumption) from your own data, quote a fixed price in writing, and stand behind the work with a 10-year insurance-backed warranty from MCS-certified, NICEIC-registered engineers. Where the case does not stack up, we tell you plainly.
Common objection we hear: battery payback is always ten years. It is not, for the right profile it is six to eight, and we prove it from your own data or walk away. See the battery storage myths we debunk, or read whether commercial battery storage is worth it.
Get a free battery plus existing solar (self-consumption) feasibility
Responds within one working day
- 1. Free desk feasibility from your meter data and roof, no obligation.
- 2. Site survey and a fixed-price proposal, itemised in writing.
- 3. Install and aftercare by MCS-certified engineers.
- MCS Certified
- NICEIC
- RECC
- TrustMark
Common questions
How much does battery storage for a business cost in the UK?
As a 2026 rule of thumb, fully installed commercial battery storage lands at roughly £400-£700 per kWh of usable capacity for behind-the-meter systems, falling toward £250-£400/kWh at multi-MWh scale. A typical 250 kW / 500 kWh peak-shaving system is around £150,000-£300,000; a 100 kW / 200 kWh resilience system around £75,000-£140,000; a 1 MW / 2 MWh system £600,000-£1.2m. Cost turns on the power-to-energy ratio, chemistry, switchgear, and any grid-connection works. Qualifying plant attracts 100% AIA on the first £1m and a 50% first-year allowance on the balance.
What payback should a business expect on battery storage?
For behind-the-meter systems doing peak shaving and solar self-consumption, simple payback in 2026 typically falls between six and eight years, faster where red-band DUoS exposure or solar surplus is high. We build the number from your half-hourly meter data and share the full spreadsheet so your finance team can stress-test it. We treat any frequency-response or Balancing Mechanism income as upside, not the foundation of the case.
Does battery storage pay back without solar?
Yes, when your bill carries enough peak and DUoS exposure to shave. Standalone peak shaving and demand-charge reduction stand on their own economics, and they are common on half-hourly-metered sites with spiky, predictable demand. Solar strengthens the case by adding self-consumption value, but it is not a precondition. We model the standalone case and the with-solar case side by side so you can see which streams drive the payback.
What is peak shaving, and how does a battery cut DUoS charges?
DUoS (Distribution Use of System) charges vary by time-of-day band, the red band, typically weekday late-afternoon into early evening, is far more expensive per kWh than green or amber. A battery charges in cheap periods and discharges across the red band and your demand peaks, cutting both the unit charges and the capacity-based standing charges. It also reduces exposure to the Capacity Market and residual charges. The saving is largest for sites with spiky, predictable demand.
Is a business battery sized in kW or kWh, and what is the difference?
Both, and they measure different things. Power (kW) is sized to the peak you need to shave or the load you need to support. Energy (kWh) is sized to how long that peak lasts. Most behind-the-meter commercial systems land at 1.5-2.5 hours of duration, for example 250 kW / 500 kWh. We pull at least twelve months of half-hourly meter data and model power and duration against your DUoS bands and solar surplus before recommending a size.