Smooth transition to AS4 protocol for electricity for [Stadtwerke Detmold]

The customer

Stadtwerke Detmold supplies the region with electricity, natural gas, drinking water and district heating, and diligently pursues its goal of offering local residents climate-friendly, sustainable solutions at fair market prices.  Proximity to residents plays an important role – in addition to providing comprehensive online services, the company also gives everyone the opportunity of calling in at its customer centre in Detmold’s town centre to speak to someone in person.

The challenge

As a provider of electricity and gas, Stadtwerke Detmold is a participant in the German energy market, to which other electricity producers, electricity exchanges and network operators also belong. The communications between these parties are known as market communication, or MaKo for short. This market communication includes the transmission of meter readings, for example, as well as customer and supplier data. Previously, most of this communication was handled via email. 

Now, the legislator has revised the guidelines for exchanging electricity market data – to ensure more standardisation, better security for the exchange of data and information, and a higher level of reliability and interoperability: Since 1 April 2024, all MaKo messages relating to electricity must follow the Applicability Statement 4 (AS4) messaging protocol, which is a standardised method for exchanging documents and messages over the Internet: as a web service with digital signatures and encryption. Communications must also be secured by following BSI (Federal Office for Information Security) guidelines, using smart metering PKI (Public Key Infrastructure) certificates, and by complying with specific cryptographic requirements. This applies to the exchange of data regarding electricity supply to customers, market processes for electricity-generating market locations, data exchange processes in metering, and balancing group billing. Participants in the electricity market need a software and hardware solution to meet these requirements. 

The next stage will require gas providers to convert their market communications to AS4 by 1 April 2025. According to the official time schedule, these providers should already be prepared for the migration and have selected a suitable solution. By 30 September, they should have tested and implemented the solution. Up to 31 March 2025, both the old and new communication systems can operate in parallel, but communications must be switched completely to AS4 from 1 April 2025.