Commercial Solar Battery Storage: Is It Worth It for Business?

Installed prices for commercial lithium iron phosphate (LFP) batteries in 2026 commonly fall into these ranges:

• Small commercial, 20 to 50 kWh: around £600 to £700 per kWh
• Mid-size, 50 to 200 kWh: around £500 to £600 per kWh
• Large or containerised, 200 kWh and above: around £400 to £500 per kWh, and lower again above 1 MWh

Some installers quote lower figures, particularly for simple battery-only additions using modular systems, so the ranges you see online and in quotes can differ quite widely. Always compare quotes on cost per kWh of usable capacity, not nominal capacity.

The price usually covers the battery modules, the power conversion system or hybrid inverter, the battery management system, the enclosure, controls, installation and commissioning. Additional costs can arise from:

• Fire separation, ventilation or an external enclosure
• Upgrades to switchgear or the main distribution board
• A revised G99 grid application
• Groundworks for containerised systems

A commercial battery can create value in three distinct ways, and a good proposal models each one separately:

• Solar self-consumption: storing midday surplus that would otherwise be exported for a few pence per kWh, then using it later when you would pay 24p to 29p from the grid. The value per kWh is the gap between your import price and your export rate.
• Tariff shifting: charging from the grid when electricity is cheap, often overnight, and using that energy during expensive daytime or evening periods. This works with or without solar, and in winter as well as summer.
• Peak network charges: many half-hourly metered businesses pay higher distribution charges during weekday peak periods, often called the red band, whose timing varies by network operator. A battery that discharges during those hours can reduce them.

For most businesses, no single stream justifies the battery on its own. The case usually rests on combining them, which is why the battery's control strategy matters as much as its size. Ask each installer to show the annual value of each stream separately, so you can see which assumptions carry the business case.

Solar and batteries are often sold as a package, which can make a battery look like a natural extension of the solar case. It usually is not. A battery's return depends mainly on how much surplus you export and on the price differences in your electricity tariff, not on the size of your solar array.

Consider two businesses with identical 100kWp systems:

• A factory running weekday shifts uses almost all of its solar output as it is generated. On most days there is little surplus to store, so a battery adds little to the solar saving.
• An ambient warehouse with low daytime demand exports a large share of its summer output. A battery can capture that surplus, but only on days when stored energy is used in the evening or the next morning.

In both cases, the strongest additional value often comes from tariff shifting and peak charges, which have nothing to do with the solar panels. If your tariff has a flat unit rate all day, a large part of the potential battery value disappears.

So before deciding on storage, look at your tariff and half-hourly data, not the solar proposal.

Take an ambient warehouse with a 100kWp solar system that exports around 40,000 kWh a year, mostly in summer. It is considering a 100 kWh battery at £500 per kWh, a total of £50,000. Assume grid electricity at 25p, exports at 5p and around 90% round-trip efficiency.

• Solar surplus: if the battery captures around 16,000 kWh of surplus a year, each unit is worth roughly 20p more used on site than exported. After losses, that is about £2,900 a year.
• Tariff shifting in winter: if the business can charge overnight at 15p and avoid 30p peak-time electricity on around 165 winter weekdays, discharging about 90 kWh a day, that adds roughly £2,000 a year after losses.

Together that is about £4,900 a year, a simple payback of just over ten years. If the business claims the Annual Investment Allowance at 25% corporation tax, the effective cost falls to around £37,500 and payback to under eight years.

Add red-band network charge savings and the case improves; remove the tariff spread and it weakens sharply. These figures are illustrative, but the pattern is typical: commercial batteries are often marginal investments, and the tariff is what decides them.

Batteries tend to make strong sense for businesses that:

• Export a large share of their solar output, such as ambient warehouses, schools during holidays or sites closed at weekends
• Trade into the evening, such as retail, hospitality and leisure, where demand continues after solar generation falls
• Are on time-of-use tariffs with a large difference between cheap and expensive periods
• Pay significant red-band network charges on half-hourly metered supplies
• Have a constrained grid connection, where a battery can store generation that an export limit would otherwise curtail
• Need resilience, where a battery configured for backup can keep critical loads running during a power cut

Batteries tend to make weak sense for businesses that use almost all their solar output during working hours, are on flat-rate contracts and have no evening demand. For many offices and single-shift factories, solar alone is the better investment.

If you are unsure, ask for a design that is battery-ready, with a hybrid inverter or space allocated for storage, so you can add it later without replacing equipment.

A battery should be sized to the energy you can realistically move each day, not to the size of the solar array. Oversizing is common, and the extra capacity often sits unused for much of the year.

Use your half-hourly data to answer three questions:

• How much surplus solar is exported on a typical summer day, and how much on a typical spring or autumn day?
• How much electricity do you use during expensive periods, such as weekday evenings or the red-band hours?
• How much can you charge cheaply overnight, given your supply capacity?

A battery that fills and empties once a day on most days earns far more per kWh than one that only cycles fully in midsummer.

Power rating matters as well as capacity. A battery's kW rating limits how quickly it can charge and discharge, which determines how much peak demand it can cover in a short red-band window. Ask installers to model several battery sizes, as they would for the solar array itself, and to show the marginal value of each step up.

Lithium iron phosphate (LFP) is now the standard chemistry for commercial batteries. Compared with nickel manganese cobalt (NMC) cells, LFP offers longer cycle life, better thermal stability and lower fire risk, which matters for installations inside or close to buildings.

Key figures to compare between quotes:

• Cycle life: commercial LFP systems are commonly rated for around 6,000 or more full cycles before capacity falls to 70% to 80% of the original.
• Warranty: 10 years is typical, with a guaranteed minimum capacity at the end. A 10-year, 80% guarantee is stronger than a 10-year, 70% one.
• Usable capacity: the capacity you can actually use, which may be lower than the nominal figure.
• Round-trip efficiency: the share of energy returned after charging and discharging, often around 85% to 90% for the whole system.
• Throughput limits: some warranties cap total energy throughput, which can expire before the time limit if you cycle heavily.

Commercial batteries widely used in the UK include systems from BYD, Huawei, Pylontech, Solis and SolaX, along with larger integrated units for industrial sites. Ask who handles warranty claims and how quickly a failed module would be replaced.

A commercial battery stores a large amount of energy, so where and how it is installed matters. Before committing, consider:

• Location: indoor installations need suitable fire separation and ventilation, while larger systems are often placed in external enclosures or containers away from buildings and escape routes.
• Fire detection and suppression: larger systems typically include detection and, in some cases, suppression within the enclosure.
• Access for the fire service: clear signage and isolation points help firefighters identify and isolate the system.
• Insurance: tell your insurer before installation. Some insurers set conditions on battery location, separation distances or the type of system.
• Building control and planning: external containers may need planning consent, and installations must meet relevant building and electrical regulations.

LFP chemistry significantly reduces risk compared with older chemistries, but it does not remove the need for proper siting. A competent installer should provide a fire risk assessment for the proposed location and explain how the system meets the insurer's requirements.

Many businesses install solar first and consider a battery later, once they have a year of generation and consumption data. This is often the most sensible approach, because the data shows exactly how much surplus there is to capture.

Adding storage later is straightforward, with a few points to check:

• Inverter compatibility: a hybrid inverter can connect a battery directly. Otherwise, an AC-coupled battery with its own inverter can be added alongside the existing system.
• Grid connection: the network operator assesses all generation and storage combined, so a battery that can export may need a new or revised G99 application.
• Controls: the battery's control system needs to read your site's import and export to avoid charging from expensive grid power by mistake.
• Space: plan a suitable location, ideally identified when the solar is installed.

If you think a battery is likely in future, ask for the solar design to be battery-ready, and include planned storage in the original G99 application where possible. Our G99 grid connection guide explains why combined applications are usually quicker.

A battery proposal is only as good as the data and assumptions behind it. Before you request quotes, gather 12 months of half-hourly consumption data, your current tariff structure including any time-of-use rates, and your network charges if you are half-hourly metered.

When proposals arrive, check that each one shows:

• The cost per kWh of usable capacity
• The annual value from solar surplus, tariff shifting and peak charges, listed separately
• The assumed number of cycles per year and the round-trip efficiency
• The payback with and without capital allowances
• The warranty term, end-of-warranty capacity and any throughput limit

Ask for the payback of solar alone and of solar with storage, so you can see what the battery adds. Our guides to commercial solar payback and system sizing explain the solar side of the calculation. When you are ready, compare quotes from up to three MCS-certified commercial installers for solar, storage or both.