Hydrogen in the German Market

Hydrogen offers the advantages of requiring only water as raw material for its generation, which is totally renewable, it emits no carbon or other pollutants when used, and it provides an efficient way to store and transport energy for use in practically every energy application.

The process by which electricity is used to split water into hydrogen and oxygen is electrolysis. Electrolysis was formally defined by Michael Faraday in 1833 with his two laws of electrolysis.

Hydrogen can be injected directly into the gas grid, to reduce by up to 10% the environmental impact of natural gas. It can also be used by transport or industry. In vehicles, hydrogen is not combusted like petrol or diesel, but rather used in a fuel cell, which recombines hydrogen and oxygen to water, while passing electrons through a circuit, providing power.

Hydrogen can be combined with carbon dioxide to produce methane (methanation via the Sabatier reaction), or biological methanation, which has typically 8% energy loss.

The storage capacity of the German natural gas network is 200 TWh, compared to the German pumped storage potential of 40 GWh. Since only about 10% of gas in the grid can be pure hydrogen, there is therefore five thousand times more storage capacity in synthetic gas storage in existing infrastructure in Germany than hydroelectric pumped storage. Estimates of storage requirements in Germany are 16GW in 2023, 80GW in 2033 and 130GW by 2050. Gas loses far less energy in transport (<0.1%) and distribution than electricity (8%).

Efficiency of power to H2 to power is 34-44%, whereas the efficiency of power-to-methane varies from 30-88%.

P2-Power and Heat (cogeneration) H2 = 48-62%, CH4 (SNG synthetic natural gas) = 43-54%. [Source: Fraunhofer IWES, February 2011]

PEME Proton Exchange Membrane Electrolysis

SOEC Solid Oxide Electrolysis Cell

HyDeploy: H2 in the UK Gas Grid. Funded by Ofgem. Blends 20% H2 in the normal gas supply. The carbon savings amount to 6 million tonnes of CO2 in the UK, equivalent to 2.5 million car emmissions. H2 is a major component of ‘town gas’, which is coal gas. Before North Sea gas in the 1960s, up to 60% by volume of gas used by public utilities was H2. Current limits on H2 content in gas vary from 0.1% in the UK to 12% in Netherlands.