Site assessment: How to assess whether your site is suitable for BESS

Before an industrial BESS installation (battery energy storage system) can be designed, there needs to be clarity on whether it can be placed at that address at all. A battery system takes physical space, connects into the company's electrical installation, and must be placed so that it can be built and operated lawfully. A site assessment, that is an evaluation of the site itself, is the systematic review that determines whether those preconditions are in place before both parties spend time on a detailed design.

This article describes the assessment process itself: what is looked at, in which order, and why the individual factors carry the weight they do. The purely physical space requirements and the installation layout are covered in their own article in this guide. The purpose here is not to repeat those points, but to show how they form part of an overall suitability assessment together with grid connection, access, and the conditions that determine whether the system can be built lawfully.

What a site assessment clarifies

A site assessment is about uncovering preconditions, not about designing the system. The purpose is to reach a clear yes or no on whether there is a basis to proceed, and to do that early, so a project does not first fail on a physical or legal precondition once the detailed work has already started.

Two factors are hard preconditions. One is the size of the grid connection, where our standard offer typically assumes at least 400A. The other is whether the system can be built lawfully at the address, which among other things concerns distance to residential areas and noise. Alongside those two preconditions sit a range of physical conditions on the site itself: how much space there is, how access works, where the cable must run, what the ground is like, and how close the system can be placed to the company's electrical panel. Together they form a picture of whether the site is suitable, and what may need to be resolved before the site is suitable.

The physical conditions on the site

The first thing a site assessment looks at is the conditions the company itself controls on its own plot.

Space and placement. An industrial BESS installation takes physical space, and it must be placed somewhere with room for both the system and the work that has to take place around it. There is no single public standard size for all installations; space need is a concrete project assessment, which the Danish Emergency Management Agency's (Beredskabsstyrelsen) guidance on fire protection of larger lithium-ion battery storage and BESS also points toward when it describes that layout, distances, and access conditions must be assessed specifically for each project. As an illustrative starting point, the foundation for four units typically occupies about five to six metres in length, with around one metre more per additional unit, but that is an indicative order of magnitude and not a fixed measure, because the concrete placement depends on the site.

Access. The modules must be transported to the placement location, and there must be access for the vehicles and equipment the installation requires. Access conditions are also part of the fire-safety assessment, because the emergency services must be able to reach the system. If the access route is narrow, blocked, or without load-bearing capacity for heavy transport, that is a condition that needs to be resolved early.

Ground and foundation. The system stands on a foundation, and it is the ground that must carry the load. The soil conditions at the specific location determine how the foundation must be built, and soft or uneven ground can mean extra work. The foundation is a building structure, and the Danish Building Regulations (Bygningsreglementet) set minimum requirements for construction that the foundation must meet. The physical preparation work, including the foundation and fire-related enclosure, is covered in its own article in the guide; in a site assessment, the ground counts as a condition that must be able to support a system, not as detailed construction work.

Proximity to the panel and cable route. The system must connect into the company's electrical installation, and the distance from the placement to the relevant electrical panel matters. The longer the cable must run, the more work and materials the cable route requires, and the routing path must be able to be established without conflicting with other elements on the site. Work on fixed electrical installations may only be carried out by an authorised electrical contractor business, and part of a site assessment is therefore to clarify whether the existing panel and its location suit the system, or whether a new electrical panel must be established to connect the system to the installation.

Grid connection and power

Alongside the physical conditions, the grid connection stands as the precondition that most often decides whether a project is relevant.

Our standard offer typically assumes a grid connection of at least 400A, which in a standard 400V three-phase system corresponds to a power of approximately 277 kW. That figure, which the local distribution system operator (DSO, netselskab) calls a delivery capacity (leveringsomfang), describes how much power the company is maximally entitled to draw from the grid. 400A is a practical rule of thumb for us, not an official threshold, and the underlying mechanisms and the grid connection itself are covered in their own article in this guide, so here it is treated only as one of the factors a site assessment establishes.

A battery differs from ordinary consumption in that it both draws and sends power. A connection therefore requires agreement on both a delivery capacity and a feed-in capacity (indfødningsomfang) with the DSO, and an existing delivery capacity is not in itself the same as capacity for a battery. The grid connection therefore cannot be read from the company's consumption alone; it is a separate clarification with the DSO. In addition, a freestanding battery is connected with its own service cable out to the connection point the DSO designates, and it is the owner who establishes and pays for that cable. How quickly a connection can be realised depends on the DSO's processing and on whether spare capacity is available, and there is no fixed processing time that can be promised in advance.

Noise and distance to housing

The second hard precondition, whether the system can be built lawfully, depends to a large degree on the distance to residential areas. An industrial BESS installation has components that can emit noise, and the placement must therefore be seen in relation to what the surroundings can tolerate.

There are indicative noise limits for external noise from businesses, which form the basis for the authorities' assessment of how much a business may burden its surroundings. The limits depend on how the area is used, and they are lower at night and in purely residential areas than in mixed residential and commercial areas. In physical planning, the authorities also designate zones around businesses where noise exceeds the indicative limits, and where housing may not readily be established. That is the background for why the distance to residential areas is not a fixed number, but depends on the specific location. In practice, the distance often lies in the order of 30 to 40 metres for our ZG-261 unit, but the precise distance is site-specific and is clarified precisely through a site assessment based on placement, area type, and the system's conditions. It should therefore never be treated as a universal rule, but as something assessed concretely for the individual address.

When production security is part of the picture

For some companies, a battery system is not only a question of shifting consumption in time, but also of protecting critical processes against power interruptions. If backup power, reserved capacity, or critical loads are part of the consideration, that changes what an assessment must uncover, because it is then not only the site, but also the concrete critical loads, that must be mapped.

That angle is covered separately in the guide, where the installation is viewed from a production-security perspective, and where the mapping of critical loads and a possible STS or other backup function is examined in depth. In an ordinary site assessment, production criticality is therefore included mainly as a question of whether that track should be activated at all. If the answer is yes, a more detailed investigation follows along that track; if the answer is no, the assessment stays with the general suitability this article describes.

Red flags and limitations

A site assessment can also end with a no, and that is part of the purpose. Some conditions make a system less obvious or entirely unrealistic, and they should come to light early.

The clearest red flag is a grid connection that is too low, or where the DSO cannot provide room for both delivery and feed-in. Another is property ownership: if the company does not own its plot, a physical installation becomes both a legal negotiation with the landlord and a practical installation task. When a BESS installation is not the right solution is covered separately in the guide, and a site assessment is precisely where those factors are assessed concretely against the individual company's situation, rather than assuming that a battery always makes sense.

There is also a product question that belongs early. Our standard model as a turnkey process is built around a minimum of two modules, because that is the configuration the full coordination and market participation rest on. A company can in principle buy a single module without the full package, but that is a narrower product: here the customer handles market participation themselves, and we deliver operational documentation rather than the complete, coordinated process. A site assessment therefore also clarifies which of the two tracks applies.

ZynexGroup's approach to site assessment

We use a fixed checklist when we assess a site, so the same factors are covered every time. It covers space and placement, the cable route to the panel, the panel's suitability and any new electrical panel, the ground and foundation, access conditions, and noise and distance to residential areas. On top of the physical conditions sit the two hard preconditions: a grid connection of at least 400A, and clarification of whether the system can be built lawfully at the address.

The purpose of the checklist is not to sell a particular system, but to reach an honest yes or no. Some of the factors a site assessment uncovers lie within the company's own plot and can be resolved with the right preparation work. Others, such as the grid connection and the building permit, sit with the DSO and the municipality, where it is the individual municipality that handles building applications and issues building permits and, via a local development plan (lokalplan), can set local frameworks. We prepare and handle the dialogue with both the DSO and the municipality, but we cannot guarantee in advance either a grid approval or a building permit. Throughout the process, the company has one fixed contact person with us from the first enquiry, so the same person knows the site from the assessment through to ongoing coordination.

Overall perspective

A site assessment is the clarification that ties the physical, electrical, and legal preconditions together into one picture of whether a site is suitable. The physical conditions (space, access, cable route, ground, and panel proximity) lie on the company's own plot. The grid connection of at least 400A and the clarification of whether the system can be built lawfully, including noise and distance to housing, are the two hard preconditions. All concrete figures for distance and foundation are site-specific and are clarified through the assessment itself, not in advance. The result is a yes or no on an informed basis, and a company that knows its grid connection and its conditions on the site can move more quickly through the assessment toward a possible design.

Have your facility's potential assessed

If you are considering an industrial BESS installation, the natural starting point is the factors this article has described: your grid connection in amperes, the space and access you have on the site, and the distance to the nearest residential area. We use that type of information for an initial assessment of whether there is a match, and for a data-based dialogue on whether the site is suitable and whether there is reason to proceed. You are welcome to contact us here.