How to connect battery storage to the distribution grid – step by step

27 October 2026 · 6 min read

Grid connection decides whether the storage project happens at all. The grid operator decides – but how well the application is prepared and how quickly the design takes its conditions on board is up to you.

Who decides on the connection

Whether and at what power a storage system is connected is decided by the distribution system operator – in South Moravia, the Zlín region and Vysočina it is EG.D, in North Moravia and in Central and Northern Bohemia ČEZ Distribuce, in Prague PREdistribuce. The operator decides only on the basis of a submitted connection application; nobody can find out the spare grid capacity in advance. Capacity is also allocated in the order of complete applications, so the most valuable thing is to apply early and correctly.

The investor influences three things: how well they know the site, how complete an application they submit and how quickly the design takes the operator's conditions on board. That is exactly the path we describe below.

Step 1: Intent and site check

At the start, the cadastral area, plot numbers and an idea of the power and capacity are enough. Public sources show what stands in the project's way before any money goes into it:

Zoning plan – whether the area allows technical infrastructure or energy generation.
Protection zones and utilities – MV and HV lines, gas pipelines, water mains, railway, roads; what has to be avoided or relocated.
Nature and soil protection – agricultural land fund, flood zones, protected areas.
Nearest lines and transformer stations – from these you can estimate whether the connection will end at low voltage, or whether you will need your own transformer station and a medium-voltage connection.

The result is a decision on whether it makes sense to continue and at what power to apply for connection. What the site check cannot do is confirm grid capacity – that comes only with the operator's statement. More in grid connection.

Step 2: Connection application

From the operator's point of view, battery storage is both a generating plant and a consumer: it feeds into the grid and charges from it. The application is therefore submitted for the generating plant (export to the grid) and usually at the same time for consumption (charging from the grid) with the corresponding reserved input power. The application includes:

a site plan marking the plot and the expected point of connection,
a single-line diagram with the ratings of the inverters and transformer and the metering point,
technology data: power to the grid (this is what gets reserved), capacity, type and number of inverters, control method,
the landowner's consent and proof of the title to the land,
the operator's form and applicant details.

What matters most is completeness. An incomplete application is returned for completion and the place in the queue is lost. A well-prepared application is at the same time the first piece of design documentation – the site plan and diagram are simply developed further later on.

Step 3: Statement and connection contract

The operator assesses the impact of the storage system on the grid and in its statement confirms or adjusts the power and point of connection and sets conditions. The deadline for the statement is set by the connection conditions decree; for larger outputs, where the grid impact is calculated, it tends to be longer. In the statement you will find:

the point of connection and voltage level (LV, or MV with your own transformer station),
the reserved power for export and the reserved input power for consumption,
the share of connection costs under the decree,
technical conditions: disconnection point, protection, metering, communication with the dispatch centre,
any enabling investments – what the operator has to build or reinforce first.

Once the connection contract is signed, the capacity is yours. The contract sets deadlines by which the storage must be connected; an unused reservation can lapse. If the operator reduces the power or refuses the connection, the project can be adjusted: lower power, limited export to the grid, a different point of connection or connection at a higher voltage level.

Step 4: Connection conditions in the design

The technical conditions from the contract must appear in the documentation, otherwise the installation will not pass commissioning. For storage systems these are most often:

Requirement	What it means in the design
Disconnection point	A switching device that disconnects the storage from the grid – a circuit breaker or switch-disconnector at LV, a switchgear panel at MV; it is operated by the grid protection and, in defined cases, by the operator.
Grid protection	Voltage and frequency protection set according to the Distribution System Operating Rules; the settings are documented in a test report.
Metering	Location and design of the billing metering according to the operator's connection conditions; for larger outputs, metering on the MV side.
Dispatch control	Communication with the dispatch centre and the ability to curtail export on its instruction.
Grid impact	Limits on flicker, harmonics and unbalance – documented by calculation or by the inverter manufacturer's data.

Each operator's requirements differ slightly. It pays to go through them with the contract in hand before the technology is ordered.

Step 5: Permit and construction

Storage needs a project permit under the Czech Building Act. The permit documentation (DPZ) contains the cover and summary reports, site plans, drawings of the structures, the fire safety solution and a documentary part with statements from utility operators and the concerned bodies. After the permit comes the detailed design, which is used to select the contractor and to build. What the authorities want to see is covered in a separate article on permit documentation for storage.

Step 6: Commissioning

Before the first parallel connection, the operator checks that the installation matches the contract and its conditions, and requires the prescribed documents and tests. Only then is the storage connected to the grid and starts doing what it was designed for – whether that is load shifting, trading on the electricity market or ancillary services.

How long the whole process takes

The operator's statement itself is a matter of weeks. The whole path from application through design, permit and construction to connection is considerably longer – for battery storage usually a year or more, depending on the power, the plot and whether the operator has to reinforce the grid. That is why we recommend applying right at the start and preparing the design while waiting for the statement.

Frequently asked questions

Can I apply for connection before I have a design?

Yes, and that is the right order. A site plan, a single-line diagram and technology data are enough for the application. The detailed design is produced according to the operator's conditions.

What if the operator reduces the power?

Consider adjusting the project: lower power to the grid while keeping the capacity, limited export at certain hours, or an MV connection. Most refusals can be worked around.

Does storage need its own transformer station?

From hundreds of kW upwards the operator usually requires an MV connection and therefore your own transformer station. Smaller storage systems on an existing site can use the existing LV connection if it has the capacity.

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