Traditional hydropower is reaching the limit in Germany. Only three percent of electrical power comes from reservoirs and rivers. Further development is difficult because the environmental impact of building a dam or weir is simply too great. The dismissal of new hydropower plants, however, only applies to traditional construction methods. Water falls downwards and the potential energy released in the process can drive a turbine. Hence, there is a second possibility that has not yet been exploited: kinetic energy - in simple terms: water’s flow velocity. If small rotors with generators are anchored in a river, large amounts of energy can be generated by connecting multiple turbines in an array. Damming of rivers isn’t necessary, and there is minimal impact on the environment. Some start-ups have already tried this, but so far all have failed.
Technology from e-scooters
This is where Energyminer comes in. The company was founded in 2021 by Dr. Georg Walder and Dr. Richard Eckl. Together with Chantel Niebuhr and an ever expanding team, they have been developing this new technology. There is much to suggest that they will achieve a kinetic hydropower breakthrough. They have a new technical concept, which works with low voltages below 60 volts, thus, ensuring safety and cost efficiency. The founders “borrow” electrical components from e-bikes and e-scooters, which reduces the costs to a tenth of previous concepts. A so-called Energyfish is anchored in the water and “swims” in the current like a real fish, hence the name. One of these Energyfish weighs around 150 kilograms and can be carried to remote stretches of river by four strong people, put into operation and dismantled again when the permit expires. Through this, Environmentalists are satisfied. A steel frame holds back large fish, while small fish safely pass through the rotor because it turns so slowly.
“We’re engineers and very familiar with mechanics and electrical engineering,” says Georg Walder, “but we don’t know much about IoT, cloud and web development.” The founding team urgently needed support and turned to AWS, which recommended kreuzwerker. Energyminer’s advantage: AWS provided financial support for kreuzwerker’s workload - a model designed to make it easier for young companies to enter the cloud.
From water into the cloud
The expertise of Energyminer and kreuzwerker harmonize on the riverbank. There, the Energyfish transmits sensor data such as water temperature, rotor speed or current power to a base station, which is shared by a dozen energy fish, via the powerline - i.e. by piggybacking on the power cable. From there, the data is transmitted via 5G mobile communications into the AWS cloud where it is analyzed and stored. This IoT platform was built by kreuzwerker. “The decisive factor was the development of a data schema and a data transmission concept,” says Peer Müller, kreuzwerker team manager. When and how often which data is transferred was the subject of extensive thought - in this project, as well as in many other projects for which kreuzwerker has already implemented such IoT platforms. “The prerequisite is always that you understand the application,” says Müller, “and that’s only possible when the customer is part of the team.”
KPIs regarding the amount of energy generated over time and the locations of the various Energyfish can be extracted from the information in the cloud, and these are then displayed on a map view. kreuzwerker created a simple dashboard that shows the most important information via a web interface. In the next step, the partners would like to build a more elaborate dashboard that contains more advanced functions. This could be diagnostic data that indicates the failure of a worn-out part.
100 Energyfish for 470 households
The dashboard data still comes from a simulation, as there is currently (November 2023) only one Energyfish in operation at a mill near Munich. Everything is running smoothly there, and Energyfish are now scheduled to go into mass production. The approval process has begun for several locations in Bavaria. As there are no fundamental water laws against the operation, Georg Walder expects to receive approval quickly. “The authorities were initially surprised because they were unfamiliar with something like this, but there is now a lot of interest, and the feedback has been positive.” A school of 100 Energyfish spread over a 400-meter stretch of river would supply up to 470 households around the clock. The school of Engeryfish would save 2300 tons of CO2 annually. This can significantly reduce a community’s carbon footprint.
As soon as the permits have been granted, the first systems will be set up in spring. After that, the plan is to gradually move ahead with further locations in German-speaking countries, then in Europe and later around the world via a licensing model. In ten years, Energyminer wants to have installed one gigawatt of electrical power - and thus replace a large nuclear power plant. kreuzwerker designed the IoT platform with a data lake and a serverless platform so that it can grow as required. Peer Müller: “Thousands, tens of thousands or even many more Energyfish can be controlled via the platform without it reaching its limits. That’s when it will pay off that we opted for serverless.” kreuzwerker always makes sure, Müller continues, that the customer can operate the platform themselves. “We don’t want to make customers dependent, but rather want to advise and enable our customers.”
A basis for community energy
Georg Walder is optimistic that Energyminer’s business model will prove successful. His team achieved costs of 4.4 cents per kilowatt hour in a simulated scenario. In Germany, the feed-in tariff for a kilowatt hour is currently over 12 cents - a good profit that Energyminer would directly invest in new electrical installations. In contrast to other start-ups that have failed with similar kinetic hydropower concepts, Energyminer will not sell its electrical installations, but operate them itself. Georg Walder promises:
“Whether companies or citizens - anyone can invest and receive a guaranteed return. With kreuzwerker’s technical expertise, as well as infrastructure and managed services from AWS, we will continue to pursue this vision.”