Battery storage for business in 2026: what's actually changed
Commercial battery storage — a behind-the-meter battery energy storage system (BESS) — lets a UK business store electricity and use it when it is most valuable. We design commercial and industrial battery storage systems sized from your half-hourly data, and unlike an energy supplier or a battery manufacturer we are independent and supplier-neutral: we show the £/kWh cost and payback upfront. Here is how commercial energy storage stacks up in 2026.
For most of the last decade, a commercial battery was hard to justify on cost alone. That has changed. Installed costs for commercial-scale battery energy storage have fallen from around £800 per kWh in 2020 to roughly £200–£450 per kWh in 2026, dropping towards £140–£240/kWh for larger containerised systems. At the same time, business electricity has become both more expensive and more volatile, and the grid-flexibility markets that pay batteries to help balance the system have widened. The result is that a behind-the-meter battery now stands on its own commercial feet, with no subsidy — something that simply wasn't true a few years ago.
How the savings stack up
A well-designed system rarely relies on one saving. It shaves your weekday peak to cut red-band DUoS charges and the most expensive units; it charges on cheap overnight power and discharges into the daytime peak (energy arbitrage); if you have solar, it lifts self-consumption from around 55% to 85%-plus, turning low-value export into avoided import; and on larger sites it earns grid-flexibility revenue. Most businesses see a 10–30% cut in their electricity bill before any market revenue is counted. We work out which streams apply to your site from your half-hourly data — see our cost and payback guide for worked numbers.
The tax and VAT position — and what competitors get wrong
Two facts are routinely stated incorrectly elsewhere, so it's worth being precise. First, capital allowances: 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 cap. Batteries are a "special-rate" asset, so they do not qualify for 100% Full Expensing; for spend above £1m, a 50% First-Year Allowance applies. Second, VAT: the 0% VAT relief on battery storage applies only to domestic and qualifying charitable buildings. Commercial installations are standard-rated at 20% — but any VAT-registered business recovers that in full, so the effective cost is the net figure. We quote both gross and net so there are no surprises.
Sizing, safety and the grid connection
Commercial battery sizing is driven by two numbers read from your load: power (kW), set by how much peak you want to remove or back up, and energy (kWh), set by how many hours that power must run. Modern systems use lithium iron phosphate (LFP) cells — chosen for thermal stability and cycle life — run at 88–92% round-trip efficiency, and are warranted for 6,000–10,000 cycles. Every install is designed to the IET Code of Practice for Electrical Energy Storage Systems, with your insurer engaged before energisation. The grid connection (a G99 application to your DNO) is usually the longest item in the programme, so we submit it early. If your connection is already constrained, that's often a reason to install a battery — not a blocker — because it lets you draw more power on site during peaks without a costly reinforcement.
If you want the numbers for your own site, the fastest route is a free desk feasibility: send us a year of half-hourly data and we'll model the system, the value streams, and an honest payback within 7 working days.
