ChallengeSWK Stadtwerke Krefeld AG is a publicly owned multi-service provider in North Rhine-Westphalia, Germany. It serves the 8,000-strong community of Wachtendonk, where about 80 percent of the electricity is generated by decentralized energy sources, primarily photovoltaic panels. While the integration of renewable energy is in line with the so-called “energy transition”, distribution grids are usually not prepared for the high infeed of volatile energy sources that can produce very strong voltage fluctuations and cause instability, shortages, and overloads. To keep the distribution grid stable despite the high percentage of electricity coming from renewables, SWK Stadtwerke Krefeld AG was looking for a way to cost-efficiently modernize the grid.
Wachtendonk is a very small community with a large number of energy suppliers – primarily photovoltaic stations. Unfortunately, these suppliers also produce very strong voltage fluctuations.Carsten Liedtke, Chairman of the Board, SWK Stadtwerke Krefeld AG
SolutionSiemens and SWK Stadtwerke Krefeld AG will transform the existing power supply system in Wachtendonk into a smart grid for research purposes.
As part of the project, Siemens Smart Grid is installing smart meters in about one hundred homes and many distribution boxes. Their function is to collect the status-related data needed to operate a smart grid. The smart meters feature a special add-on function known as the power snapshot analysis: It enables snapshots of key parameters and turns the devices into “eyes” for monitoring grid activity.
Five new intelligent secondary substations will also act to ensure greater stability. Their function, among other things, is to compensate for voltage dips, which can result when clouds form over the solar panels in Wachtendonk. The substations are equipped with communications-capable medium-voltage switchgear, adjustable local transformers, and remote-control and distribution grid automation components.