Unique research project "Underground Sun Storage"

Federal Minister of Transport, Innovation and Technology Alois Stöger, Managing Director of the Austrian Climate and Energy Fund Theresia Vogel and RAG Chief Executive Officer Markus Mitteregger open the Underground Sun Storage test facility in Pilsbach, Upper Austria.

Growth in solar and wind power generation demands sustainable solutions for seasonal energy storage. Large underground gas storage facilities already safe and reliable Power to gas technology enables conversion of surplus electricity into hydrogen or methane – Underground Sun Storage project to look into storability of hydrogen as an additive to natural gas and synthetic methane in pore reservoirs.

Klimafonds-Geschäftsführerin Vogel, Technologieminister Stöger und RAG-Generaldirektor Mitteregger bei der Eröffnung (Foto: Klima- und Energiefonds/APA-Fotoservice/Vogl)

Forschungsanlage „Underground Sun Storage“ (Foto: RAG)

Die Projektpartner mit Minister Stöger (4.v.r.: Foto: RAG)

Vienna and Pilsbach, 5 October 2015: For the first time, a research project will investigate the possibility of storing wind and solar power at a former gas field. The storage project is based on power to gas technology, which converts electricity generated in this way into a mixture of methane and hydrogen.

The project was granted EUR 2.8 million by the Austrian Climate and Energy Fund established by the Ministry for Transport, Innovation and Technology, as part of its energy research programme. The research project should be completed in 2016, at a total cost of EUR 4.5 million.

Federal Minister Alois Stöger commented: “Research facilities like this one make a valuable contribution to implementing developments in renewable energy technology, one of our key focus areas. Energy research represents a vital investment for the future and strengthens Austria’s position as an industrial location. It also plays a part in ensuring safe, environmentally friendly and affordable energy supplies.”

Theresia Vogel, Managing Director of the Austrian Climate and Energy Fund, said: “The Climate and Energy Fund’s energy research programme supports essential technological breakthroughs and reductions in the cost of Austrian energy technologies. The power to gas facility in Pilsbach is a milestone that sends a clear signal beyond Austria’s borders, and will deliver key insights for the energy system of the future.”

RAG CEO Markus Mitteregger explained: “Gas can be transported in large quantities safely and out of sight via existing underground infrastructure, and held in environmentally friendly natural gas storage facilities that are also already in place. Austria’s geology is ideal for underground storage, so the country is able to make a major contribution to security of supply.”

Solar and wind power output is erratic because of changing weather conditions, meaning that generation cannot be adjusted in response to demand as is the case with conventional power stations. In some parts of Europe, such as the north of Austria’s Burgenland province, the amount of power generated by wind farms is already well in excess of demand on windy days. With wind and solar generating capacity growing fast, energy storage is becoming an increasingly pressing issue. And even Austria’s pumped storage plants in the Alps are no longer sufficient to meet this need. 

Power to gas has been widely discussed as a potential solution to the storage problem for some time. The technology uses surplus solar and wind power to split water into oxygen and hydrogen. The hydrogen can then either be directly injected into the gas grid, or converted into methane – the main constituent of natural gas – by means of a methanation process using carbon dioxide. At present direct hydrogen admixture is the more economic option, due to its higher efficiency and the shortage of suitable sources of carbon dioxide. However, up to now there has been no research into the effects of hydrogen on the storage capacity employed by natural gas infrastructure – the underground storage facilities. 

An Austrian consortium led by RAG has addressed this issue, and is carrying out research into underground storage of a mixture of hydrogen and synthetic methane in the test facility that has now opened. 

Markus Mitteregger added: “The results from laboratory tests conducted as part of the project have been very promising, and have fed into implementation of the test facility. We are even more excited about the data and insights that operating the new installation will generate.”

RAG’s project partners are the University of Leoben; the University of Natural Resources and Life Sciences, Vienna; the Energy Institute at Johannes Kepler University Linz; Verbund; and Axiom Angewandte Prozesstechnik

The project partners from outside Austria are Nafta (Slovakia), Etogas (Germany), the German Technical and Scientific Association for Gas and Water, or DVGW (Germany), and Hychico (Argentina).

Further information and a video about the project can be found at www.underground-sun-storage.at.