The world is currently in a transition from using fossil fuels for the supply of energy, to an energy system that is largely based on sustainable sources—the Smart Grid. The energy transition can, however, be challenging because of the difference in availability of new energy sources and their specific production pattern. While the share of intermittent renewable energy sources—such as solar energy and wind energy—increases, the need for flexibility in our energy system becomes stronger.

Power to gas (P2G) is seen as a smart integration of existing technologies, which can provide flexibility to the electricity sector. The conversion of electricity into gaseous energy carriers—i.e. hydrogen and/or methane—can be stored in the gas grid infrastructure. Electricity should be accommodated as such whenever possible. If power congestion occurs or if power transmission capacity is fully utilized, power can be converted into hydrogen and added to the gas infrastructure. Whenever the addition of hydrogen is being limited—e.g., the influence of higher concentrations of hydrogen on the combustion behavior of the gas mixture at the end user—hydrogen can be converted into methane.

The chemical synthesis of carbon dioxide (CO2) to methane (CH4) by a catalytic reaction with hydrogen (H2) is called “methanation” or “hydrogenation of CO2.” This process is better known as the Sabatier reaction, for which Paul Sabatier received the Nobel Prize in 1912.

Besides the role of methanation in accommodating large amounts of hydrogen into our current gas infrastructure and storing renewable energy, this process enables the recycling of CO2. The production of substitute natural gas from methanation of renewable hydrogen and CO2 contributes to the replacement of fossil natural gas. Although it is not a viable measure for decarbonizing our entire energy system or storing CO2, it can contribute to a reduction of fossil gas use.

DNV KEMA investigates the viability and applicability of power to gas systems on the macro, meso, and micro level. Not only can DNV KEMA oversee the playing field and characteristics of the entire power to gas value chain, but we also have hands-on experience with the chain components, such as electrolysis and methanation. DNV KEMA applies its knowledge about, and experience with, both the power and gas system to foster the transition to a cleaner and a more sustainable energy future in the Smart Grid.

By: Lukas Grond, specialist, Sustainable & Smart Energy, DNV KEMA Energy & Sustainability

For more information on P2G, please view Jorg Gigler’s post “Power to gas systems in Smart Grid: An introduction.”