Installation of Battery Energy Storage Systems (BESS) on Ground Screws — European Standards

The installation of a battery energy storage system (BESS) on ground screws in the EU is governed by Eurocode 7 for the geotechnical design of point loads and standard EN 1990 for load combinations, while fire safety separation distances between containers are regulated by national provisions of individual member states.

Two levels of regulation: foundation construction and operational safety

Just as with wooden buildings, the rule of two areas of expertise applies to BESS as well. Geotechnical foundation design (screw pile, its length, load-bearing capacity, spacing) is governed by Eurocode 7. The structural design of the container frame and load combinations are addressed by EN 1990 and subsequent Eurocodes for steel structures (EN 1993). Electrical and fire safety of the BESS operation as a technological facility is a separate area, which in the EU is governed by the international standard IEC 62933 and national fire regulations — it is not directly related to foundation geotechnics, but the investor and designer must address it simultaneously.

Eurocode 7 — point loads from containers

Eurocode 7 (EN 1997-1, Section 7 — Pile Foundations) applies to ground screws for BESS in the same way as to other types of loading. A detailed general overview of the standard can be found in a separate article: Eurocode 7 and screw piles.

Specific to BESS is the load profile:

Concentrated point load. Unlike a distributed surface load (e.g., in a PV mounting system), each ground screw beneath a BESS container transfers a significantly higher unit load concentrated at several support points. A structural engineer must verify the load-bearing capacity of each individual screw as well as the entire group (group effect per EC7 §7.6.2).

Combination of vertical and horizontal loading. Wind on the side wall of the container generates a horizontal component that must be transferred by the screw and the supporting head together with the vertical load — design approach DA1 (combinations 1 and 2) is standard in the Czech Republic, Slovakia, Austria and Germany.

Documentation for each point separately. Due to the higher unit load, it is common with BESS to document the telemetry record (torque × depth) for each individual screw pile rather than just a sample—this serves as a basis for the structural engineer and for investment insurance.

EN 1990 — load combinations

EN 1990 (Eurocode: Basis of structural design) specifies how to combine individual loads (self-weight, imposed load, wind, snow, and potentially seismicity) into design combinations that both the foundation and the load-bearing structure must satisfy.

For the BESS container, the following are particularly relevant:

Permanent load — dead weight of the container and batteries (tens of tons depending on the type and battery chemistry)
Climate impact — wind on the side surface, or snow on the container roof in locations with relevant snow loads
Extraordinary load — in seismic regions (especially southern Europe) supplemented by Eurocode 8

National annexes of individual EU countries regulate partial safety factors and combination rules — a project implemented in the Czech Republic cannot be transferred to Germany or Italy without modification.

IEC 62933 — BESS safety as a technological equipment

International standard IEC 62933-5-2 (Safety requirements for grid-integrated electrochemical energy storage systems) governs the electrical and operational safety of the storage facility itself — not the foundation geotechnics. It is important for the investor to know that:

IEC 62933 addresses batteries, control systems, and fire protection inside the container.
Eurocode 7 and EN 1990 address the foundation and the load-bearing structure
Both areas meet in the project documentation, but they are assessed separately and often by different specialists.

Concrete foundations (footings, piers, strip foundations) are created by excavation, reinforcement with steel rebar, and pouring cement concrete. Before loading, it is necessary to wait 7–28 days for curing. The load-bearing capacity reaches 20–100+ tons per point, but at the cost of significantly higher expenses and a longer time.

Fire separation distances — national regulations

Unlike Eurocodes, there is no harmonized European standard for separation distances between BESS containers. This area is governed by national fire regulations and in practice is assessed individually with the local fire authority or an authorized fire safety expert.

Practical impact for EPC contractors: Clearance distances affect the placement of containers on the site, and thus also the layout of the foundation points. We recommend addressing the fire safety concept before the geotechnical foundation design is finalized—changing the container layout after driving the ground screws is costly.

How BESS projects are addressed in key EU countries

Czech Republic Geotechnical design according to CSN EN 1997. The fire safety of the BESS is assessed by an authorized fire safety specialist as part of the building permit documentation.

Germany: DIN EN 1997 as a national implementation of EC7. BESS installations above a certain capacity are subject to approval under the BImSchG (Federal Immission Control Act) and VDE requirements for electrical safety.

Austria: ÖNORM B 4435 complements Eurocode 7. The fire safety assessment of the BESS is handled by the local fire service authority (Landesfeuerwehrverband) depending on the size of the installation.

France: NF EN 1997 as a national implementation. BESS above a certain capacity falls under the ICPE (Installations Classées pour la Protection de l’Environnement) regime with its own setback and safety requirements.

Poland: PN-EN 1997 as a national standard. The growth of the BESS market in PL is driven by a combination with PV projects, with geotechnical design standardly in accordance with Eurocode 7.

In all countries: the geotechnical foundation according to Eurocode 7 + EN 1990 is universal across the EU, while fire and operational approvals are always addressed by local legislation and local authorities.

Checklist for BESS project on ground screws in the EU

Container technical datasheet with point loads from manufacturer BESS
Geotechnical site investigation and bearing capacity assessment according to EN 1997
Structural calculation of load combinations according to EN 1990 (incl. wind, possibly seismicity)
Design of load-bearing heads/profiles for point load transfer into the screw
Fire safety concept and separation distances according to national regulations — to be resolved prior to layout fixation
Telemetry record of the installation for each screw (torque × depth)
Geodetic verification of flatness within the container manufacturer's tolerance
CE certification of the drilling machine and documentation for the building authority

Frequently Asked Questions

Is there a harmonized European standard for the separation distances of BESS containers?
No. Separation distances are regulated by the national fire codes of individual EU countries, not by a harmonized European standard. They need to be addressed with the local fire authority or an authorized person.
How does the geotechnical design for a BESS differ from that for a photovoltaic structure?
The BESS container transfers the load to several concentrated points with a higher unit load, while the PV mounting structure distributes the load evenly across a larger number of lighter points. Eurocode 7 addresses both situations, but the design of the individual screw and the assessment of the group effect differ.
What role does IEC 62933 play in a BESS project?
IEC 62933-5-2 governs the electrical and operational safety of the storage system itself (battery, control system, fire protection inside the container). It is not related to foundation geotechnics, which is covered by Eurocode 7 and EN 1990.
Is it necessary to recalculate the foundation structural analysis for each EU country?
National annexes of Eurocodes regulate partial safety factors and combination rules, which is why a structural calculation prepared for one country is not automatically valid in another. We recommend cooperation with a local authorized structural engineer.

Where to continue

How the installation of the foundation for BESS containers works in practice: Battery storage systems on ground screws

General overview of geotechnical design according to Eurocode 7: Eurocode 7 and screw piles