Battery storage for business: how it saves and earns money

A business battery does several jobs, not one. Here is how it saves and earns money, how to size it, and what real configurations at Czech sites look like.

A battery on a company site is more than a backup for the odd power cut. Well controlled, it switches between several jobs a day: shaving the demand peak, storing cheap or self-generated power and releasing it when power is expensive. What it saves depends on your load profile, contract and operations.

Five ways storage saves and earns

Peak shaving

Distribution charges include reserved capacity, and demand is measured in 15-minute intervals. Exceeding the reservation is penalised. A battery covers the short peaks, so you can reserve less and still stay within it.

An illustrative example: a factory with a 940 kW peak manages with 700 kW of reserved capacity once a battery is in place. We walk through the calculation in our article on peak shaving.

−240 kW
of reserved capacity in an illustrative factory example

Time shifting

Since 1 October 2025, the European day-ahead market, including the Czech market operator OTE, has traded electricity in 15-minute periods. On sunny days, midday prices can fall close to zero or below, while evening prices are several times higher. A battery charges in cheap quarter-hours and discharges in expensive ones; the more closely your contract tracks spot prices, the more this is worth.

Solar self-consumption

A battery holds the midday surplus from your roof for the afternoon and evening, when you would otherwise buy from the grid. In an illustrative example, it cut grid purchases by 24% on the example day. More in solar plus storage.

Backup and island mode

If the grid fails, the battery takes over within 6 ms, so production lines, cooling and servers keep running. How long the site lasts depends on capacity and load. Combined with solar or a CHP unit, it can run in island mode for longer.

Ancillary services

Where market rules allow, the battery can offer the grid flexibility in FCR and aFRR through an aggregator. Payment covers having the power on standby, not only the energy actually delivered.

And one more: electrification without a bigger connection

EV chargers for a company fleet or heat pumps can run into the limits of the grid connection. The battery covers the extra demand at peak times, so you can postpone the upgrade, and sometimes skip it altogether.

How to size it

Start with what the battery should do. For peak shaving, power in kW decides: how much of the peak it has to cover. For time shifting and solar self-consumption, capacity in kWh decides: how much energy it must hold, and for how long.

The basis is your 15-minute metering data, ideally for a full year so that seasonal swings show up. Add your reserved capacity, any on-site generation and your type of supply contract. The data show how often and how long the peaks last, and whether you need power or capacity more.

An oversized battery ties up money; an undersized one misses its purpose. That is why we size from data, not from estimates.

A modular system from 243 kWh to 6 MWh

Our storage is built from modules. The base module has 243 kWh and 100 kW, a sub-container offers up to 200 kWh of usable capacity, and one system scales to 6 MWh. Efficiency is 95%, and each module works on its own.

It runs down to −25 °C without heating: waste heat from the liquid-cooled inverters keeps the batteries warm, with no compressor cooling. A trailer or a 3 t forklift can move it, and 125 A sockets are enough for a temporary connection.

The control system plans charging around next-day spot prices using OTE data, shaves peaks, fills valleys and switches to backup automatically. We design and build the storage in the Czech Republic from European components and guarantee spare parts for 10 years after the warranty ends.

Real configurations from Czech sites

Configurations at Czech sites vary widely:

SiteCapacityPower
Food producer0.27 MWh50 kW
Mountain resort1.46 MWh600 kW
Factory1.7 MWh700 kW
Large leisure campus4 MWh2 MW

The ratio of capacity to power hints at the job. More capacity per kW means longer delivery, for example into the evening after a sunny day; more power per kWh means a strong but short intervention, typically against a demand peak.

Rent, lease or buy

You don’t have to buy straight away. Rental is a flat fee based on the rental period and the number of cycles, and if you buy later, the rent counts towards the price. A lease is paid from the savings while we keep ownership. If you buy, all savings and revenue are yours.

Grant calls for energy storage open regularly in the Czech Republic, for example under the Modernisation Fund. We can help you choose a programme and prepare the application.

Send us your 15-minute metering data via the energy storage page and we will work out what a battery would do on your site.

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