World's largest Power-to-Gas plant for generating methane enters operation
Stage prior to industrial application achieved
ZSW completes 250-kilowatt research plant for storing green electricity. Baden-Württemberg's Environment Minister Franz Untersteller: "The plant is a successful step in establishing the new technology."
A further hurdle en route to achieving the marketability of Power-to-Gas technology has been overcome: on 30 October 2012, the Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (Centre for Solar Energy and Hydrogen Research, ZSW) inaugurated a research plant with a connected electrical load of 250 kilowatts. The plant, which has been funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), converts green electricity into hydrogen and methane. With a possible methane production of up to 300 cubic metres per day, it is the largest plant of its kind worldwide and ten times more powerful than the test plant constructed at ZSW three years ago. The scientists from Stuttgart are therefore close to achieving the industrial application of the new electrical storage technology.
Together with their colleagues from the Fraunhofer IWES research institute and the SolarFuel company, the ZSW researchers want to continue optimising the technology during operation. That should make it easier to scale up Power-to-Gas plants into the 1-20 megawatt range relevant for the energy industry. The R&D work is also concerned with assessing future storage requirements.
The 250-kilowatt plant comprises an alkaline pressure electrolyser, a methanisation unit and a process control system for regulating the plant. "Our research plant works dynamically and intermittently. In contrast to the first plant, it can respond flexibly to fluctuating energy supplies from the wind and sun and can also respond to sudden interruptions," explains Dr. Michael Specht, head of ZSW's Renewable Fuels and Processes research department and one of the fathers of the new technology. "That is a requirement for future energy systems with a high proportion of renewable electricity." Another advantage for its application is that the control and regulation technology corresponds to the technology used by future large-scale industrial plants.
Baden-Württemberg's Environment Minister Franz Untersteller praised the progress made with the Power-to-Gas technology: "In order to master the challenges posed by the energy revolution, we need innovation and new technologies. With a continually growing proportion of renewable electricity, this also includes the research and use of storage gas. The 250-kilowatt research plant is a successful step in establishing the new technology." In particular, the Federal State of Baden-Württemberg as a centre of the automotive industry can benefit from Power-to-Gas because the process also offers alternatives for future mobility, explained Untersteller.
In 2013, the next chapter in the Power-to-Gas success story will be written in Werlte in Lower Saxony. On behalf of Audi AG, SolarFuel is constructing a 6-megawatt plant there with the aim of attaining the industrial application stage. The experience gained from the ZSW's 250-kilowatt research plant will also be incorporated into the Ingolstadt-based company's "e-gas" project.
The proportion of green electricity in the German grid is growing enormously. That is presenting the energy system with new tasks: with a high proportion of wind and solar energy, the electricity volume fluctuates considerably in accordance with the weather conditions. In some regions it is already no longer possible to feed surplus green electricity into the grid. Between 2020 and 2030, surplus electric power in the gigawatt range can be expected throughout Germany during specific seasons.
Without long-term storage systems with high capacities, which will need to be constructed by then, future surpluses cannot be made available to consumers for periods when there is no wind and sun. The chemical storage media, hydrogen and methane, provide long-term storage with large volumes. Only these are capable of being stored for long periods and without losses, and can be fed into Germany's large, well-developed gas grid. CHP plants, natural gas vehicles and industry can use the renewable gas.
The research and development work on the plant is being funded by the German Federal Ministry for the Environment, Nature Conservation and Reactor Safety (BMU) (Funding Code 0325275A-C).
The Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (Centre for Solar Energy and Hydrogen Research Baden-Württemberg, ZSW) is one of the leading institutes for applied research in the area of photovoltaics, renewable fuels, battery technology, fuel cells and energy systems analysis. There are currently around 220 scientists, engineers and technicians employed at ZSW's three locations in Stuttgart, Ulm and Widderstall.
The research areas of the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) cover the entire spectrum of wind energy as well as the integration of renewable energies in supply structures. Around 400 scientists, employees and students work at Fraunhofer IWES. The IWES has been formed by combining the former Fraunhofer Centre for Wind Energy and Maritime Technology (CWMT) in Bremerhaven with the Institute for Solar Energy Supply Technology (ISET) in Kassel.
SolarFuel GmbH from Stuttgart develops Power-to-Gas plants for storing surplus green electricity in the form of hydrogen and methane. The gas is stored in the existing gas grid and, by using efficient CHP plants, can be converted back into electricity anywhere in Germany and at any time for use in industrial and mobility-related applications. By integrating strongly fluctuating sources such as the wind and the sun in a reliable energy supply, the technology meets an important requirement for future energy systems.