Standard Cases Checked in Seconds

The expansion of solar photovoltaics and e-mobility is fundamentally changing the demands placed on low-voltage grids. For grid operators, this means, above all, a sharp increase in the number of connection requests that need to undergo a technical check. At the distribution system operator Netze BW, that check had been a predominantly manual process that was increasingly being pushed to its limits. Together with Fichtner, a solution was developed that digitizes the checking process, automatically produces a computable model of the grid, and quickly assesses requests. This is based on a digital twin of the low-voltage grid that is updated daily.

Netze BW receives 40,000 to 60,000 requests per year for low-voltage grid connections of photovoltaic installations alone. About 60,000 requests were expected in 2026, with the potential for as many as 100,000 per year in the future. Every decision must be technically sound, because it is directly related to grid capacity, operational reliability, and compliance with technical limits.

The starting point of the project was a typical operational bottleneck. Until now, the requests have been checked by grid planners, simulated in the grid model, and then assessed. However, the process that has been used so far is labor-intensive when faced with large quantities of requests and has limited scalability. This is exactly where automated connection checks come in. Standard cases should be processed quickly, consistently, and reliably, while complex cases should continue to be referred for in-depth review.

Before the solution was implemented on a large scale at Netze BW, the project partners first tested the approach in a proof of concept involving five secondary distribution substations. At the same time, a model of the entire low-voltage grid was set up to verify the quality and completeness of the source data.

“Most requests are straightforward – standard rooftop solar systems that qualify for permits. But checking them still took up time and resources. Now Netze BW has the opportunity to take an in-depth look only at the complex cases that truly require planning.“

From Request to Technical Assessment

Netze BW had already laid important groundwork for this in advance. Customers were already able to submit their requests digitally through a grid connection portal. The solution developed by Fichtner builds on that existing process. It collects the relevant information, locates it within the grid, and assigns it to the appropriate grid area. In the background, data from several systems is consolidated before the actual grid check begins.

This turned the digital submission of a request into an end-to-end checking process. Fichtner worked with Netze BW to implement the necessary process steps and integrate them into the existing system landscape. With Fichtner, the technical assessment now takes less than 30 seconds. So what used to take several days or weeks, depending on the case, can now be processed automatically in a very short time for standard cases.

A Digital Model of the Grid as a Basis

At the heart of the solution is a digital twin of the low-voltage grid. Fichtner imports data from Netze BW’s geographic information system (GIS) and processes it to create a digital grid model for calculations. That model is generated automatically and updated regularly. Building on this, the industry-standard calculation software PowerFactory is used – a tool for analyzing electrical grids that provides the technical basis for assessing connection requests.

The technical solution is based on several modules of our Fichtner Digital Grid software portfolio for distribution system operators. One module handles data import, grid structure processing, and error detection. Another serves as a web interface for visualization, verification, and quality assurance. The solution is complemented by the grid model with its interface to PowerFactory, as well as the module for automated connection checking. In this way, Fichtner Digital Grid combines data consolidation, grid calculation, and process automation within a single architecture.

The scale of the project is evident from the numbers alone: The model includes more than 25,000 secondary distribution substations and maps a 100,000-kilometer-long low-voltage grid with millions of individual grid points and connections. The entire grid territory is remodeled daily – in less than two hours. This ensures that an up-to-date and reliable grid basis is available every day for the connection check.

Full Automation Requires Clear Rules

The real challenge began with the transition from calculation to automation. After all, the system was not allowed to simply approve as many cases as possible, but rather only those that were truly non-critical in the grid. To achieve this, the solution required clear technical rules. It must reliably recognize when a connection to the existing grid is still possible and when a case requires further review. Reservation management is also important in this context because it factors in not only existing facilities, but also reserved and approved requests. This ensures that decisions regarding connection requests remain consistent, even when multiple requests simultaneously affect the same grid areas.

Data Volume and Data Quality Had to Be Made Manageable

Technical scaling was also a challenge. The database is large, needs to be processed daily, and must be updated quickly enough that ongoing operations are barely affected. In the pre-project phase, the full grid calculation had taken about eight hours. In the Netze BW project, this step was reduced to just under an hour and a half. In the meantime, incoming requests are placed in a queue and then processed automatically.

“Handling these massive amounts of data and ensuring that everything runs efficiently was crucial.”

It also became clear that a system like this stands or falls on the quality of its data. Errors in GIS data, implausible switch positions, or conflicting information from different systems can directly impair computational capabilities. Quality assurance therefore also includes systematic analysis of the grid structure. This reveals data gaps, faulty connections, and implausible switch positions.

Fichtner as the Interface Between Grid Planning, Data Systems, and IT

It is precisely at this point that it becomes clear that the project was far more than a traditional software project. Fichtner not only implemented a technical solution, but also supported Netze BW in the functional structuring and translation of the requirements – with cross-departmental collaboration enabling an end-to-end, one-stop solution. Requirements from grid planning, GIS, data management, and the operational process had to be consolidated, prioritized, and translated into a viable software logic. Step by step, a solution emerged that works in day-to-day practice.

Existing modules of Fichtner Digital Grid, client-specific requirements, and interfaces were integrated in such a way as to create a practical, comprehensive system.
At the same time, it was important that the solution not only work today, but also be able to grow with future demands. Fichtner Digital Grid is designed to be scalable and capable of evolving. As part of the project with Netze BW, a Software-as-a-Service (SaaS) operation was implemented for this purpose.

Faster Pace in Routine Operations, Greater Focus for Skilled Personnel

The benefits of this solution are clearly evident in day-to-day operations. Standard cases can be assessed automatically, while complex requests are specifically sent for manual review. This significantly reduces the workload for the grid planning department. Skilled personnel no longer have to deal with every routine case in detail. Instead, they can focus their attention on areas where analysis and experience are truly needed. For a grid operator dealing with a high volume of requests, this is an important step toward ensuring that connection processes remain manageable over the long term.

The approach proved effective beyond its immediate practical application: In 2025, the solution received EnBW’s group-wide innovation award, InnoKlaus. The automated connection check team beat 30 competitors to win that award. In this context, Netze BW described the solution as one of the most advanced systems in German-speaking countries.

Since going live at the end of 2025, approximately 1,000 requests per week have been processed automatically – a number that continues to rise, but which is being handled without any problems. For now, standard cases are still being spot-checked for plausibility by skilled personnel. The next step is to fully automate the entire process at Netze BW, including integration with the customer portal, so that standard cases can be approved in the future without manual verification.

Basis for Further Applications

The digital twin provides a basis that goes beyond the actual connection check. Issues such as data quality, additional automation steps, or further analyses will be easier to address in the future on this grid basis. This provides Netze BW with a solid operational foundation for further development of the low-voltage grid. At the same time, Fichtner demonstrates in this project how complex business, technical, and process requirements can be integrated into a scalable solution.

June 2026