Battery storage for business — FAQs

A commercial battery typically costs £200–£450 per kWh of capacity installed in 2026, falling towards £140–£240/kWh for larger containerised systems. In whole-project terms, that's roughly £45,000 for a small 100–150 kWh system up to £450,000+ for a 1 MWh peak-shaving install. Cost has dropped from around £800/kWh in 2020. The capital usually falls inside the £1m Annual Investment Allowance, so it's fully deducted against profits in year one.

Most of our commercial models land between 4 and 10 years simple payback. The exact figure depends on how many value streams stack on your site: peak-shaving and red-band DUoS avoidance, off-peak/peak arbitrage, solar self-consumption uplift, and grid-flexibility revenue. Sites with a spiky daytime peak and a half-hourly meter hit the lower end. We model the real number from your meter data before you commit a penny.

Four main ways, usually combined. It shaves your peak demand to cut red-band DUoS and available-capacity charges; it charges on cheap overnight power and discharges during the expensive daytime peak (arbitrage); if you have solar, it stores surplus generation so you use it instead of exporting it cheaply; and on larger systems it earns grid-flexibility income from the Capacity Market, frequency response, and the Balancing Mechanism. Most businesses see a 10–30% cut in their electricity bill before any market revenue.

Yes — this is 'revenue stacking', and it's often what makes a commercial battery a strong investment rather than a marginal one. A behind-the-meter battery can earn from the Capacity Market, frequency response services (Dynamic Containment, Moderation and Regulation), the Demand Flexibility Service, and — since the P415 reform opened the Balancing Mechanism to aggregated assets — the wholesale balancing markets. It's run through an aggregator that bids your asset into the best market each day. The income is site-specific and not guaranteed, but on larger systems it can add £20,000–£100,000+ a year.

No. A battery is valuable on its own through arbitrage and peak-shaving — it charges from the grid on cheap power and discharges during expensive periods, with no solar involved. If you do have solar, a battery is usually the best next investment because it lifts self-consumption from around 55% to 85%-plus. We model both standalone and solar-paired options for every site.

Often, yes — and it's one of the most valuable uses. A behind-the-meter battery lets you draw more power on site during peaks than your agreed import capacity allows, because it discharges to make up the difference. That means you can add EV chargers, new machinery, or extra shifts without a costly DNO reinforcement. We've deployed storage specifically to avoid six-figure connection upgrades.

Modern commercial systems use lithium iron phosphate (LFP) cells, which are far more thermally stable than the NMC chemistry behind most headline incidents. We design to the IET Code of Practice for Electrical Energy Storage Systems: cell-level battery management, thermal control, gas/heat detection, suppression where the design requires it, and compliant separation distances. Containerised systems sit outside the building, and your insurer is engaged before energisation, not after.

Commercial LFP systems are warranted for 6,000–10,000 full cycles, or 10–15 years, typically to 70% retained capacity. Real-world life is often longer because the battery rarely cycles to its full depth every day. Systems are modular, so capacity can be augmented later rather than replaced wholesale. We model degradation explicitly so the year-10 savings in your proposal are honest, not the showroom figure.

No — and this is a common misconception. The 0% VAT relief on battery storage applies only to domestic and qualifying charitable buildings, and runs until 31 March 2027 before rising to 5%. Commercial and industrial installations are standard-rated at 20% VAT. The good news: any VAT-registered business recovers that VAT in full through its normal return, so the effective cost is the net figure. We quote both gross and net so there are no surprises.

Battery storage is plant and machinery and qualifies for the Annual Investment Allowance — 100% of the cost deducted against profits in year one, up to the permanent £1m AIA cap. For a profitable limited company at 25% corporation tax, a £200,000 battery delivers around £50,000 of tax relief. Batteries are a 'special-rate' asset, so they do not qualify for 100% Full Expensing, but for spend above £1m a 50% First-Year Allowance applies. We hand your accountant a clean breakdown.

It's set by two numbers, both read from your half-hourly data: power (kW), based on how much peak demand you want to remove or back up; and energy (kWh), based on how many hours that power must run — usually the 2–3 hour daily peak window. A typical mid-size commercial system is 250 kW / 500 kWh (a '2-hour' battery). We never size from floor area or a rule of thumb alone — we size from your actual load shape.

From contract to commissioning, typically 12–28 weeks. The physical install is 1–4 weeks. The long pole is usually the DNO: a G99 connection runs 8 weeks to 12 months depending on capacity and local network headroom. We submit the G99 application immediately after survey so the grid process runs in parallel, not after, the rest of the project.

Yes. A battery can be AC-coupled to almost any existing commercial PV array, or DC-coupled where the inverter supports it. We assess your existing G98/G99 registration and whether a variation is needed, then retrofit without disturbing the generating array. Adding storage is the most common upgrade we make to a site that already has solar but is exporting too much of it cheaply.