Solar methane research begins in Finland
Tekes – Finnish Funding Agency for Innovation – has granted € 5 million funding for a research project aiming to study energy storage and balancing in a system, where intermittent sources solar and wind have large share. The 2-year Neo-Carbon Energy project is implemented by Lappeenranta University of Technology (LUT), Technical Research Centre of Finland (VTT) and the Finland Futures Research Centre of University of Turku (FFRC). It is a multidisciplinary project looking at both technological and socioeconomic issues.
The core of the project is chemical storage or solar and wind energy as methane. Methane offers the largest storage capacity and the longest storage duration of all technologies available for storing solar energy. Already now, methane storage capacity is over 200 TWh in Germany and over 2000 TWh in UNECE countries.
This project is restricted to power-to-gas technology, which is the most popular area of solar methane research at the moment globally. However, it is important to note here, that it is only one of many technologies that could be used for the purpose, and wider technological perspective is needed in future projects.
Power-to-gas means production of gaseous fuels by electric power. Electric power may originate from any sources, including renewable, fossil and renewable. The final product may be any gaseous fuel. Therefore, these fuels may have substantially higher or lower emissions than conventional fuels. Most common of these fuels is coal hydrogen. Coal hydrogen vehicles have over 300 % higher lifecycle greenhouse gas emissions than corresponding gasoline and diesel oil vehicles. Emissions of coal methane vehicles are even higher due to the additional conversion. Although fuel cell vehicles are promoted as zero emission vehicles, their lifecycle emissions may be the highest of all.
Here the interest is in solar power and other intermittent power, which need storage. Hydrogen production by this method has been commercial for a long time, including solar hydrogen. It gives 90 % decrease in lifecycle emissions compared to gasoline in current production, and could be further improved. Solar methane is produced thermochemically by Sabatier reaction from solar hydrogen and carbon dioxide. Carbon dioxide may be separated from air, smokestacks or industrial processes. Although theory and laboratory scale production of solar methane originates from late 19th century in France, it took a long time to implement it (due to dominance of crude oil). The first demonstration scale production plant was buiilt in 2009 in Stuttgart, Germany, by SolarFuel company. The first commercial wind methane plant, by Audi, started production in Werlte, Germany in 2013 and now there are 650 wind methane filling stations in Germany.
In addition to Germany, research on this technology is being carried out in several other countries, including France (where a demonstration plant already exist), Sweden and the Netherlands. Denmark is the most advanced country in research on microbiological solar methane production, instead of power-to-gas.
Solar methane has a key role in the Finnish roadmap to sustainable transport in 2050, since it is the most practical option to enable most transport energy consumption to originate from the most sustainable and primary energy sources, solar and wind, which also have the largest resource base. For that reason renewable methane becomes the most important fuel at the end of the described sustainable path.