GP Joule: Charging park with intelligent energy management


GP Joules on-site charging park  

GP Joule's on-site charging park

  • GP Joule specializes in renewable energy – from planning and systems manufacturing to operations.
  • This also includes meeting the need for charging large electric vehicle fleets using renewable energy
  • With support from North-Tec and Phoenix Contact, a solution has been successfully implemented in the form of an energy management system connected to an OCPP backend.
  • This future-oriented and open system combines the mobility revolution with the energy revolution and is serving as a model for future charging stations.

Customer profile

GP Joule is a company that specializes in the innovative use of renewable energies – as a partner for companies, communities, and investors in all areas related to renewable energy. GP Joule builds, markets, and operates energy parks worldwide with a high degree of scalability and rated capacities of several hundred megawatts.


Dr. Fabian Sösemann and Dipl.-Ing. (FH) Ralf Breckling  

Dr. Fabian Sösemann and Dipl.-Ing. (FH) Ralf Breckling

The mobility revolution is facing many challenges – such as the ability to charge large vehicle fleets without a massive redevelopment of the existing mains connections. "The products and services we offer also include customized electromobility and energy concepts for tradespersons, companies, and communities." explains Dr. Fabian Sösemann, Senior Director for Energy Supply and Legal Affairs at GP Joule in Reußenköge. "We see the mobility revolution initiated by electromobility as one of the drivers in the system."

GP Joule operates its own motor pool, which consists of 28 purely electric vehicles – a good two-thirds of which are charged at the company site in Reußenköge. Almost 1.5 MWp of solar power and a biogas plant are on hand to meet the demand. "The major challenge is in supplying the loads while making maximum use of the renewable energy potential,“ continues Sösemann, "so that we draw as little as possible from the conventional grid.“ That was also the underlying reason why the charging concept for the company's E-parking lot was designed to use as few resources as possible.


Energy measurement devices, RCM modules, and charging controllers in the central control cabinet  

Energy measurement devices, RCM modules, and charging controllers in the central control cabinet

The solution is a master/slave system, where the charging technology is housed in a central control cabinet. Applications and processes are controlled from that location. The communications required for the charging process in accordance with IEC 61851 Charging Mode 3 is implemented for the charging points using charging controllers from Phoenix Contact's EV CC Advanced series.

The calibrated energy measurement devices, which are connected directly to the charging controllers via a serial bus, supply the information on the current power values required to manage the load. The charging controllers and RFID card readers are networked together via an Ethernet-based network that sends the data for further processing to the central controller – an Axioline 1050 from Phoenix Contact programmed for IEC 61131 using the PC Worx development environment.

Power management display in the central control cabinet  

Power management displayed on the monitor in the central control cabinet

In its capacity as a specialist in biogas plant control and automation technology, the Bredstedt-based North-Tec Maschinenbau GmbH assisted in developing the charging solution. The control processes are implemented using charging cards with different priority levels based on the intended use of the vehicle being charged in relation to the available renewable energy. "Our goal is to constantly monitor the network so that we can optimize the power consumption." explains Ralf Breckling, General Manager of North-Tec. "GP Joule's E-parking lot is located at the end of the network line for the local distribution network operator – a situation that is quite similar to the conditions in many parking garages."

And that is also precisely where a bottleneck threatening cost-effective and feasible charging power is to be expected, given the growing incidence of electric vehicle charging. "Our charging concept can be transferred as is to those types of applications," explains Sösemann, and refers to the necessity of concentrated data storage in the controller: "Feeding all of the signals to one control center also enables us to evaluate them on the accounting side."

The master/slave approach has yet another advantage: it concentrates a small number of intelligent components in a single control cabinet, making servicing the system clearer and easier.


An energy management system including a charging park has been created for the e-mobile motor pool at the GP Joule headquarters in Reußenköge using the master/slave approach. Sösemann summarizes: "As a specialist in renewable energy, we have also moved a good step further ahead in the mobility revolution now." The charging technology and hardware platform for processing the power distribution algorithms originate from Phoenix Contact. In cooperation with the development partner North-Tec a future-oriented and open system has been created that efficiently combines the mobility revolution with the energy revolution, creating a model for future charging parks.

Do you want to implement your charging solution with us?

Send us your request and benefit from our services:

  • Combination of the right hardware and software components
  • Production of charging connectors with your logo for comprehensive branding
  • Charging cable ends can come with a step cut, pre-assembled, or compacted upon request
  • Creation of tested wiring diagrams for simple and safe implementation
  • Consideration of the latest charging standards, technological standards, and the German Weights and Measures Act
  • Support during connection to billing providers and building and energy management systems


C6 The Exchange
Calmount Park
Dublin 12
D12 XE18

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