By the PPA Funding team Last updated
A commercial battery can earn income by selling flexibility to the grid, on top of cutting your bills. Through aggregators, it can be paid to raise or lower demand during frequency and balancing services, or to shift stored energy to high-value periods. Earnings vary and are not guaranteed, unlike your fixed PPA rate.
How can a battery earn money from the grid?
The electricity grid has to keep supply and demand balanced second by second. National Grid and suppliers pay for flexibility, meaning the ability to increase, reduce or shift power quickly. A battery can provide this by charging when the grid has plenty and discharging, or holding back, when it is tight.
Businesses rarely contract with the grid directly. Instead you join an aggregator, sometimes called a virtual power plant, which pools many batteries and bids them into services such as frequency response and the balancing mechanism. The aggregator handles the technical requirements and passes on a share of the revenue.
How is this different from peak shaving?
Peak shaving is about your own site: the battery discharges during your busiest periods to lower the demand charges and peak-rate energy on your bill. The benefit stays inside your own costs and never leaves the meter.
Grid services point the other way. Here the battery is paid by the wider system for being available to help balance it, which is income rather than an avoided cost. A well-sized battery can often do both, shaving your peaks most days and offering spare capacity to an aggregator at other times, though the two can compete for the same capacity.
What affects how much a battery can earn?
Revenue depends on the battery size and power rating, how much capacity you can free up after your own needs, the services your aggregator can access, and market prices that change over time. None of it is guaranteed, and payments can fall as more batteries compete for the same services.
Because of that variability, grid-service income is usually treated as an upside on top of the core case, not the reason to install storage on its own. Any figures a provider quotes should be shown as a range, with the bill savings and, under a PPA, your fixed rate per kWh guaranteed at least 30% below the grid, as the dependable part.
This guide is general information, not financial or tax advice. Your circumstances determine what applies — please confirm with your accountant or advisor. Get a tailored proposal →
Frequently asked questions
Do I need a special battery to earn grid income?
Usually you need a battery and control system your aggregator approves, plus a grid connection agreement that permits export or flexibility. Many commercial batteries are capable, but check compatibility before assuming a site can take part. Your installer or funder can confirm what an aggregator requires.
Does grid-service income affect a PPA or lease?
It can, and the arrangement varies by funder. Some PPA or lease agreements keep flexibility revenue with the funder, some share it, and some leave it with you. Ask how any grid income is split before signing, because it changes the overall value. The fixed PPA rate at least 30% below the grid is unaffected.
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