Battery Storage for Businesses: How It Works and When It Pays Its Way

Battery storage lets a business store electricity, from its own solar panels or from the grid at cheaper times, and use it when electricity costs most or when demand on the site peaks. Whether it pays depends on your tariff structure, your demand profile and how much solar you generate and export. The answer comes from your half-hourly data, not a rule of thumb.

Key points

• Batteries create value by moving energy in time: from the middle of the day to the evening, or from cheap periods to expensive ones.

• For many sites the biggest wins are using more of their own solar and avoiding the most expensive peak-time electricity.

• Half-hourly consumption data is the starting point for any serious assessment.

• Storage is classed as generation in GB, so it goes through the network operator’s connection process alongside any solar.

• Fire safety, location and insurance need early attention, because they shape where a battery can go.

How a business battery creates value

Using more of your own solar. Many commercial roofs generate more than the building uses at midday, especially at weekends. Without storage, that surplus is exported, often for less than you pay for electricity. A battery keeps it for later in the day. Our guide to commercial solar and G99 grid connections covers how export is handled.

Avoiding peak-time charges. Business electricity bills often include network charges that vary by time of day, with the highest charges in a weekday evening peak period. The exact times depend on your network operator’s region. A battery charged earlier can supply the site through that window.

Smoothing demand. Sites with short, sharp peaks, from machinery, kitchens, EV chargers or heating, can use a battery to cap the peak drawn from the grid. That can help where the site’s agreed capacity is tight, or where adding EV chargers would otherwise mean a costly supply upgrade.

Resilience. Some battery systems can supply selected circuits in a power cut. That isn’t automatic, and it isn’t the same as a dedicated uninterruptible power supply for IT or critical equipment. If resilience is a goal, specify it from the start.

Is your site a good fit?

A battery tends to make most sense where:

• You have, or are planning, rooftop solar that exports a meaningful share of what it generates.

• Your bill structure includes significant time-of-day differences.

• Demand peaks at predictable times, especially late afternoon and early evening.

• You are adding EV charging or electric heating and want to manage the impact on your supply.

It tends to make less sense where the site uses all its solar already, the tariff is flat, or there is nowhere suitable to put the battery.

The first step is your half-hourly consumption data, which your supplier can provide for sites with half-hourly metering. With that, a battery can be modelled against your actual demand and tariff, rather than generic assumptions.

Grid connection

Electricity storage is classed as generation in GB, so a battery that can export, or that is installed with solar, goes through the network operator’s connection rules. For most commercial systems that means an application under G99, and the operator assesses the whole system, solar and battery together. Newer requirements for generating equipment that includes storage came into force on 1 March 2026. Export limitation can help fit more onto a constrained connection. Allow for the application in the project timeline.

Location, fire safety and insurance

Lithium-ion batteries need careful siting on commercial premises. Points to settle early:

• Location: an outdoor cabinet away from the building, escape routes and combustible storage may be simpler to approve than an internal room.

• Separation and access: clearances around the unit, ventilation, and access for maintenance and the fire service.

• Detection and protection: what monitoring, detection and suppression the system and the location need.

• Your insurer: talk to them before you commit. Insurers may have specific requirements for battery storage, and RISCAuthority publishes guidance on lithium-ion battery storage on commercial premises.

• Fire risk assessment: update it to include the battery.

Getting these right at design stage avoids moving the battery later, which is expensive and disruptive.

Maintenance

A commercial battery should be monitored and maintained alongside the solar system: fault history, firmware, cooling, the condition of the enclosure and the protection settings. Our commercial solar maintenance page explains how we look after solar systems on business premises.

Frequently asked questions

Can a business battery work without solar panels?

Yes. A battery can charge from the grid at cheaper times and supply the site at peak times. Many businesses consider it alongside solar, because using more of their own generation is often the larger benefit.

How big should a business battery be?

It depends on the shape of your demand, your solar generation and what you want the battery to do. Sizing should come from half-hourly data, not a rule of thumb.

How long does a commercial battery project take?

The grid application is often the longest step, so start the conversation early. Design, insurer input and installation follow.

Do you install batteries for businesses you’ve already fitted solar for?

Yes, and for sites with solar from other installers. We assess the existing system and the connection first.

Request a commercial solar assessment. We’ll look at your half-hourly data, your roof and your connection, and tell you whether a battery makes commercial sense for your site.