Electricity grid makes island self-sufficient
The North Frisian island of Pellworm has been a showcase for energy research since the early 1980s. In 1983, Europe's largest solar farm was built there. In 1989, wind turbines were added to create Europe’s largest hybrid power plant. A smart electricity grid will now make the island power-independent.
With around 21 gigawatt-hours, Pellworm annually produces three times as much power as it consumes. Even so, the 1,200 people living on the island are reliant on power supplied by two 20-kilovolt submarine cables from the land grid. With a combination of wind power, photovoltaics and biogas plants with large-scale storage facilities, home storage systems and intelligent measurement technology, the island is now due to become self-sufficient in terms of power.
E.ON and Schleswig-Holstein Netz AG erected a storage system and used data connections to couple the customers’ electricity connections to the wind turbines and photovoltaic systems on the island. If excess power is generated when the wind and sun are strong, it flows into the large-scale storage system with lithium-ion and redox flow batteries, and into decentralised home storage systems. Under low wind conditions and when the sky is cloudy, the island’s residents use the power from these batteries. Controllable local grid transformers, special power electronics and an energy management system have been integrated into the electricity grid in order to improve control of the energy flows.
“Our aim is to couple power generation and consumption in such a way that we can make better use of the energy system, so that it continues to perform effectively while remaining affordable. The more successful this project is, the more energy can be used locally, and the more independent the island becomes from long-distance energy transports,” explains Matthias Boxberger, board member at Schleswig-Holstein Netz AG, summarising the goals of the “Smart Region Pellworm” research project. “With the expansion of renewable energy in Germany, we increasingly have a situation where supply exceeds demand for power to a growing degree when the wind is strong or the sun is shining brightly. As a result, the electricity grid is increasingly reaching the limit of its capacity,” says Leonhard Birnbaum, member of the board at E.ON. “We still have a lot to learn and gain a lot more experience. The Smart Region Pellworm is a very clear example of how highly promising solutions could look for the energy supply system of the future.”
Stand-alone solutions for private consumers
One of the focuses of the research project is to investigate how long-distance electricity transport and the grid expansion this requires can be reduced. A study by the German Federal Environment Agency shows that stand-alone solutions are particularly suitable for rural settlement areas in northern Germany. In particular, the electricity requirement by the industrial and commercial sectors can hardly be covered in many regions. The key, according to a study entitled „Modellierung einer vollständig auf erneuerbaren Energien basierenden Stromerzeugung im Jahr 2050 in autarken, dezentralen Strukturen“ (“modelling power generation based entirely on renewable energy in autonomous, decentralised structures in 2050”), is a well-developed electricity grid for the regional compensation of electricity production and consumption.
This flagship project is funded by the German Federal Ministry for Environment, Nature Conservation and Nuclear Safety with almost ten million euros as part of the Energy Storage Research Initiative. The project is being implemented by an innovation group from industry and science.