Industrial battery storage installation: what changes on an industrial site

What is different about an industrial site

The stages are the ones in the commercial battery storage installation guide. Four things move on an industrial site:

• The connection. Industrial sites often have an HV supply or a large LV site-specific supply, so the battery may connect through a transformer and HV switchgear rather than a simple LV board. The network operator sets the voltage and any works in its connection offer.
• The load. A process load has its own peaks, ramp rates and shift pattern. The battery is sized from twelve months of half-hourly data for the peaks it must shave, not from a rule of thumb, and the controls must not fight the plant.
• The tie-in. The battery is joined to live switchgear. That needs a planned outage agreed with production, a method statement, and a plan for what runs on temporary supply.
• The site risk. The battery joins an existing fire risk assessment, insurer arrangements and, on a multi-contractor site, CDM 2015 duties. See battery storage fire safety.

Grid connection by size: G99 types and the 5 MW threshold

G99 groups a battery that can export by registered capacity. According to the ENA Distributed Generation Connection Guide (March 2025), Type A is below 1 MW, Type B is 1 MW to under 10 MW, Type C is 10 MW to under 50 MW and Type D is 50 MW or more (or any connection at 110 kV and above), for connections below 110 kV. Most industrial behind-the-meter batteries are Type A or Type B. The same guide gives network-operator quotation clocks of 45 working days for LV and 65 for HV connections.

Larger projects may also need a Transmission Impact Assessment. In England and Wales the threshold was raised from 1 MW to 5 MW (change CMP446, May 2025) where there are no fault-level issues, according to NESO. The full process is in the G99 application guide, and who your DNO is depends on your MPAN.

Red-band charges differ by network operator

For an industrial battery, the value of discharging in the red band depends on when the red band is and what it costs, and both are set per distribution licence area. The table gives the Monday to Friday red window and the range of non-domestic red unit rates in each operator's 2026/27 schedule of charges (effective 1 April 2026). It is a distribution charge only, one component of a supplier bill, and the range covers all non-domestic tariffs and bands, so find your own tariff in the schedule.

Not listed: NGED (South Wales), SP Manweb and the two Scottish licence areas; read their own 2026/27 schedules. Times are UK clock time.

Tie-in, outages and commissioning

Ask for the tie-in to be planned into a single agreed outage, with the isolation points, temporary supplies and restart sequence written down before anything is ordered. Commissioning follows the G99 type, with the network operator able to witness the tests; see battery storage commissioning for the forms and the handover pack. On an industrial site also ask for the protection settings to be agreed with whoever maintains the site's HV network.

Siting, fire and planning

Most industrial batteries are containerised and outdoors, on a prepared hardstanding with separation from buildings and a route for the fire service; a few go in a switchroom. The design follows the IET Code of Practice for Electrical Energy Storage Systems and the references on the fire safety page, and the insurer should see the design before it is frozen. An outdoor container usually needs planning permission: see planning permission for battery storage, and containerised BESS installation for the delivery sequence.

Cost and tax

Published UK ranges put containerised systems of 500 kWh and above at about £140 to £240 per kWh, before grid works; the cost guide gives the sources. A company can claim the Annual Investment Allowance on up to £1m of qualifying spend a year, and the treatment above that depends on how the battery is classified (capital allowances). Take your accountant's advice before modelling it.

What to ask an installer for an industrial site

• Which G99 Type B (or HV) applications they have taken through your network operator, and how long each took.
• Who designs the HV tie-in and the protection, and who owns and maintains the transformer and switchgear afterwards.
• The outage plan: how long, when, and what happens if it overruns.
• How the controls were tested against a live process load, and what the battery does when the site trips.
• Who holds the CDM 2015 principal-contractor duties on your site (HSE guidance for commercial clients).
• The contents of the commissioning pack and the O&M regime, in writing. The installer checklist has the full set.