This is an article from – The Oil Drum
Hermann Pengg gave one of the more interesting presentations of the ASPO Conference.
Audi have teamed up with SolarFuel to demonstrate their ‘Power to Gas’ concept. The driver (excuse the pun) is the need for long-term storage of renewable energy to cover demand during what can be 2-3 weeks of low wind under the large high pressure systems which can sit over Europe in winter and summer. Pumped hydro storage is seen as the most efficient but storage volumes even where there are hydro schemes are usually only the order of days, and Germany has precious little anyway.
The idea is to use excess electricity to hydrolyse water into hydrogen and oxygen and then react a CO2 stream with the hydrogen to create methane, which can then be pushed into the gas grid. The gas grid has enormous storage capacity, so in this way the excess renewable energy can be stored for conversion back to electricity in gas plants when needed.
The claimed theoretical efficiency for the conversion from electricity to gas is 60% but it would be good to see more details to support that…
Very interesting article, and another important part of our future and changes we will need to consider. ~R