A comprehensive energy transition is required for climate protection and the development of local, resilient communities. Those looking to set up a system often encounter closed systems that are difficult to customise or repair, offer limited opportunity for user input and raise privacy concerns. For years, developers have offered solutions in the form of open alternatives, such as small wind turbines and charge controllers. While numerous open-source hardware projects already exist, they often remain unknown beyond a small group and, due to their prototype status or lack of user-friendly documentation, are difficult for technical laypeople to use.

As part of the OpenEnergy project and the third round of the Prototype Fund Hardware, we are aiming to drive change and have invited people to get involved. Sixteen project teams responded to the call and submitted exceptional proposals. On May 28, the jury—composed of experts in electrical engineering, battery technology, community energy, and open-source hardware development—met to review the submitted proposals. Unfortunately, the jury was only able to accept the following three projects into the OpenEnergy initiative:

• D0ry: (D0 RelaY) is an open-source measurement and control component for community-owned energy systems—specifically for PV systems, balcony power plants, and home storage units owned by private individuals. Current solutions are mostly proprietary, cloud-based, and simply unusable for renters with meters in the basement. D0ry combines two modules released entirely as open-source hardware: the battery-powered D0-LoRa read head, which records household consumption directly at the electricity meter in real time and transmits data via LoRa even through basement walls, as well as a gateway on standard ESP32-S3 boards that consolidates the measurement data and the control of the storage system and inverter into a unified, local interface.
• Wind MPPT: As part of the project, a Maximum Power Point Tracker (MPPT) for small wind turbines will be developed based on Libre Solar MPPT hardware. The MPPT is a power electronic circuit that can operate the wind turbine at the optimal operating point for maximum energy yield. The device will be equipped with an open communication interface to configure parameters and read live data.
• Bidirectional Charging Stations with Solar Inverters: Bidirectional charging enables the use of electric vehicles as battery storage to supply personal energy needs and stabilize the grid. Currently, there are no options for implementing bidirectional charging without purchasing a proprietary combination of charging station, vehicle, and electricity contract. The goal of the project is to develop and document a kit based on an existing prototype that contains all the necessary hardware components to build a bidirectional charging station.

Each of the three project teams will receive €10,000 to participate in the OpenEnergy project and will have six months to work on their projects.

The Prototype Fund Hardware team will continue to work toward securing funding for open hardware projects. Anyone interested in future calls for proposals is encouraged to subscribe to the Open Hardware Alliance mailing list.