Power to Gas: The Final Breakthrough for the Hydrogen Economy?

Abstract

AbstractIn Germany more than 20% of the energy mix is made up of renewable energy and its share is rapidly increasing. The federal government expects renewables to account for 35% of Germany's electricity consumption by 2020, 50% by 2030 and 80% by 2050. According to the German Energy Agency, multi-billion euro investments in energy storage are expected by 2020 in order to reach these goals. The growth of this fluctuating energy supply has created demand for innovative storage options in Germany and it is accelerating the development of technologies in this field. Along with batteries and smart grids, hydrogen is expected to be one of the lead technologies. 2010 a commercialization roadmap for wind hydrogen was set up by the two northern federal states of Hamburg and Schleswig-Holstein with the goal of utilizing surplus wind power for the electrolytic production of hydrogen. With the creation of the “performing energy initiative”, 2011, Brandenburg and Lower Saxony joined this undertaking. The aim of this initiative is to set up demonstration projects in order to develop and optimize wind-hydrogen hybrid systems and prepare their commercialization for the time after 2020. Beside the conversion of hydrogen into electricity and fuel for cars, further markets like raw material for the chemical, petrochemical, metallurgy and food industry are going to be addressed. Considering the fact there are over 40 caves currently used for natural gas storage with a total volume of 23.5 billion cubic meters and 400 000 km gas grid available in Germany, the German Technical and Scientific Association for Gas and Water sees opportunities for hydrogen to be fed into the existing natural gas grid network. The name of this concept is power-to-gas. According to the current DVGW-Standards natural gas in Germany can contain up to 5% hydrogen. The GERG, European Group on the Gas Research sees potential to increase this amount up to 6% to 20%. Power-to-gas could serve both for fuel and for the storage of extra energy produced by renewable sources. The hydrogen produced via electrolysis could be drawn upon – directly or as synthetic natural gas (SNG) in a second additional methanation process step – to provide electricity by means of CCGT (combined cycle gas turbines) or CHP (combined heat and power) using for example fuel cells. It could also address the industrial and household heat market. DVGW is furthermore participating in the “Power-to-Gas Platform” that was set up in 2012 by the German Energy Agency, bringing together RnD institutes, renewable energy project developers and park operators, utilities, underground storage providers in order to create political support for this new technology. Demonstration projects will be completed by 2020 in order to develop business models (for storage, production and trade of “green gas”) and devices (electrolysers, turbines, smart gas metering, compressors, storage capacities amongst others) to enable the implementation of this concept on a broad scale. This means that a multitude of industrial players will be involved in the changes that will occur in the value chain: utilities (electricity, gas), power technology companies, car makers, heating device manufacturers, but also manufacturers of measurement, regulation and control devices, suppliers of the biogas and methanation industry. Germany is the pioneer in this field. This technology however increasingly interests its neighbours, with project developments in France, Italy, Spain, and UK but also in North America and North Africa. Germany can contribute its valuable experience (e.g. legal framework for power-to-gas) to the development of these industries. German participants in demonstration projects in these countries could for example be renewable energy park operators, RnD institutes and suppliers.