Sustainable Energy Supply for Residential and Commercial Areas

Since 2021, a container has been stationed in front of Building C at Bremerhaven University of Applied Sciences. It is part of a small microgrid—an isolated grid in which energy is generated from wind and solar power and either fed into the power grid or stored in the form of hydrogen. To this end, it is equipped with various technical components, such as an electrolyzer, a fuel cell, and power converters. The energy comes from photovoltaic and wind power systems on the roof of Building C. The microgrid container was developed and built as a test laboratory as part of the project “Hydrogen—Green Gas for Bremerhaven” by, among others, Prof. Dr.-Ing. Uwe Werner. The results show that the microgrid works not only in theoretical calculations. “We use the electricity we generate to power the machine hall in Building C. Excess energy is stored in batteries and in the form of hydrogen,” he explains. On some days, the systems even generate so much energy that it can be fed back into the grid. On those days, the university building is virtually self-sufficient.

Self-Sufficient Residential Areas Thanks to Isolated Grids

What has been developed at the university could also be implemented on a larger scale. “In principle, this can be planned for any residential area. The microgrid container would just need to be larger, and more gas cylinders would be required to store the hydrogen,” says Prof. Werner. All of this could be calculated. And it’s not just about the power supply. With the help of a heat pump, buildings could also be heated. In practice, this might look like this: In a residential community, homeowners have photovoltaic systems on their roofs or small wind turbines. Together, they generate energy for the island grid, to which all homes are connected as consumers. The energy that isn’t consumed immediately flows into a microgrid container, where it is converted into hydrogen via electrolysis and stored. When needed, it then flows back to the homes at a later time. The residential area would thus be self-sufficient. But what if there isn’t enough energy? “Then we could continue to draw electricity from the conventional grid. However, the amount would be significantly lower over the course of a year. It’s quite rare for neither wind nor sun to provide energy. In the future, another possibility would be to refuel directly with hydrogen when the storage tanks are empty,” explains Prof. Werner.

Storing Wind Energy Effectively

Having hydrogen delivered—as is already the case with oil today—could indeed be an option in the future. In the “wind2hydrogen” project, researchers at Bremerhaven University of Applied Sciences are exploring ways to store energy generated by offshore wind turbines directly on site on a platform. Prof. Dr.-Ing. Uwe Werner, who leads the project, sees great potential in this approach. “The amount of energy generated offshore cannot easily be transported in its entirety via cable. To avoid overloading the grids, the turbines are then shut down. Instead, however, the energy could be stored in the form of hydrogen and transported ashore by ship. If the hydrogen is then pumped into gasworks, home heating systems can be powered entirely by green energy.” Alternatively, trucks could be equipped with hydrogen tanks and deliver the gas directly to people’s doorsteps.

Sustainable Industrial Parks Are Possible

While there are currently no concrete plans for private individuals, a project is already underway for businesses in the southern part of Bremerhaven. There, in the Lune Delta, a sustainable industrial park is being developed that is intended to be self-sufficient and powered exclusively by renewable energy. The “IWAS Lune Delta” project has delivered its first results in this regard. Among other things, the study examined whether the microgrid could not only ensure the entire electrical power supply but also reliably provide the business park with thermal energy. One of the outcomes is a tool that can be used to calculate the heat and electricity consumption of various companies. This makes it possible to determine how much energy must be available each day and whether it makes sense for several companies to collaborate—for example, to utilize waste heat rather than releasing it into the environment. “In the best-case scenario, there’s no need to connect the area to the electricity and heating grids at all,” says Prof. Werner.
Research into the potential applications of microgrids and hydrogen storage is far from complete. In addition to “wind2hydrogen,” another project called “H2Metastore” is currently underway at Bremerhaven University of Applied Sciences. Prof. Dr.-Ing. Uwe Werner is working there alongside other scientists on a storage system for compressed hydrogen.  He is convinced that Germany can achieve the energy transition and become independent of oil and gas supplies from other countries. The ideas—and the expertise to implement them—are certainly there.

Further information on the microgrid: https://www.hs-bremerhaven.de/de/forschung/projekte/h2-microgrid
Further information on the IWAS Lune Delta project: https://www.hs-bremerhaven.de/de/forschung/projekte/iwas/iwas-lune-delta
Further information on the wind2hydrogen project: https://www.hs-bremerhaven.de/de/forschung/projekte/wind2hydrogen
Further information on the H2Metastore project: https://www.hs-bremerhaven.de/de/forschung/projekte/iwas/h2meta