GP Joule: Charging park with intelligent load management


GP Joule uses photovoltaics, wind power, and biogas to charge e-vehicles  

GP Joule uses photovoltaics, wind power, and biogas to charge e-vehicles

  • GP Joule provides solutions for the generation of renewable energy from the sun, wind, and biomass, and for electromobility.
  • Many companies are faced with the question of how to ensure the needs-based supply of electric vehicles with electricity.
  • The solution is a load management system that ensures the rules-based distribution of the available connection power to all installed charging points.
  • GP Joule found a flexible solution for its company parking lot and for its customers in the EV Charging Suite software from Phoenix Contact.

Customer profile

Turn your own problem into a solution – GP Joule entered the electromobility market with this motto in 2015. Tailored solutions were scarce, and so companies were becoming providers of e-mobility and charging infrastructure themselves – almost on a green field basis – with expert partners. GP Joule Connect has been working closely with Phoenix Contact E-Mobility GmbH since 2015.


Jonas Elbroend (left), Hardware Product Development, and Piet Gömpel, Software Product Development at GP Joule in Reußenköge, Germany  

Jonas Elbroend (left), Hardware Product Development, and Piet Gömpel, Software Product Development at GP Joule in Reußenköge, Germany

The base element of a new charging park is always the charging station. “Deficiencies, for example in terms of stability, user convenience, energy efficiency, and mains connection are difficult to fix afterwards,” says Jonas Elbroend, based on his own experience as a hardware product developer at GP Joule Connect. “The built-in charging controller needs to control the current during the charging process, and also needs to be able to be controlled from a higher-level system.” Furthermore, the charging controller should be flexible so that different charging modes can be selected.

Further charging functions on the wish list included a 6 mA DC fault detection system and a 30 mA residual current device to protect the charging points and to switch the load. For charging mode 3, case B with charging socket, a voltage monitoring function should also be included in the charging controller for unlocking the charging connector in the event of a power failure.

For the load management system to be implemented, the charging points should be distributed in rotation across the three line conductors. This ensures that the maximum unbalanced load – specified by the energy provider – is not exceeded. Against this background, the hardware and software must also be well-coordinated.


Hardware and software perfectly coordinated  

The correct charging controller (lower two rows) is the basis for optimum load management

The question of how the charging park’s energy supply is ensured through the available connected load is of fundamental importance. “An energy management system is needed to control the charging park energy flow,” explains Elbroend. “This can either be autonomous – in other words, responsible for one charging park – or it can be part of a comprehensive building management system.” In an autonomous system, the available connected load is the only specified value for managing the charging park.

“The Ethernet-capable charging controllers and the EV Charging Suite software from Phoenix Contact allow ideal energy management,” explains Piet Gömpel, software product developer at GP Joule Connect. “The controllers are managed by the EV Charging Suite using Modbus TCP. The suite also manages the approval for the charging process and regulates the charging current.”

One of 30 charging stations at GP Joule  

GP Joule can extend the charging park successively as necessary

Charging park operators can either bill charging processes locally or using a billing system. GP Joule itself uses the software’s export function for billing and forwards the consumption data. In contrast, in the public sector, charging processes are usually billed by a backend provider. The backend provider receives the consumption data via OCPP – the protocol is an integral part of the EV Charging Suite.

GP Joule now operates over 30 charging stations in Reußenköge and over 20 more at other locations. Extending the number of charging points is easy with the license model for 10, 30, or 50 charging points. “Our customers often start out with a basic installation with just a few charging points,“ says Gömpel, ”and with an upgrade license, the system can be extended flexibly at any time with additional charging points.”

Convenient management in the office next door  

With the EV Charging Suite, employees have access to diagnostics information on the charging status and occupancy time

With the EV Charging Suite, the parameters for the charging park, for the individual charging points, for the load management, and for connection to the billing system are configured easily in a web-based interface – from any PC via a web browser. If, for example, the operator is logged in, relevant settings can be viewed or changed.

If a central terminal with touch PC and RFID reader is available to the electric vehicle driver to register, the charging point can be selected and the charging process started through an intuitive user interface. As an alternative, a box PC can be used and each charging point can be equipped with an RFID reader for user registration.


Using this approach, GP Joule Connect brought around 300 charging points into operation in 2019. To meet the demanding customer requirements regarding operation, energy management, and availability, functions for using cloud services are also implemented in the EV Charging Suite.

Jonas Elbroend summarizes: “The EV Charging Suite from Phoenix Contact is tailored to companies that want to use between ten and several dozen charging points in the future and which have professional requirements on energy management, operation, and upgrade assurance.“

Piet Gömpel adds: “With the EV Charging Suite, our charging solutions can be used flexibly in different environments in charging parks. We can therefore offer our growing customer base a complete solution, from analysis, through planning and implementation, all the way to operation.”

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