The Power-to-Gas technology: a bridge between electricity and natural gas networks
Coordinated by GRTgaz in association with eight industrial partners, Jupiter 1000 Power-to-Gas demonstrator, will allow to store electricity under gaseous form in order to inject it into the natural gas transport network. As the first projects are currently being implemented in France, this technology feeds many expectations for its capacity to store big volumes of electricity while minimizing losses. In addition to energy storage, Power-to-Gas can also allow to value CO2 stemming from industrial installations located nearby via methanation and find potential applications in different sectors such as mobility or smart management of the energy networks.
Power-to-Gas processes and networks’ integration
The Power-to-Gas technology (that can be found under the acronym “P2G”) refers to the transformation of electricity into hydrogen (H2) through water electrolysis. This process allows to store electricity when its production is higher than network demand. In the electrolysis process, electricity is used to “break” water molecules (H2O) into hydrogen (H2) and oxygen (O). This hydrogen mode of production is not as spread as steam reforming process with fossil fuels[i] because of its higher cost. However, it uses “fatal” electricity (potential loss because of the lack of demand) generated by renewable energy sources, and does not produce CO2.
So, Power-to-Gas answers the intermittent nature of most renewable energies (wind and photovoltaic especially) by creating a storage solution for the electricity surplus.
Power-to-Gas appears as a technology at the junction between electricity and gas networks:
Electricity conversion into gaseous hydrogen allows the opposite conversion from gas to electricity in order to match consumers’ demand when electricity production is not as high as the consumption on the network (Gas-to-Power).
Hydrogen can also be injected in the transport/distribution network of natural gas, either directly, in restricted quantities (~6%), or after methanation. The synthetic methane obtained by the combination of hydrogen and carbon dioxide has the same properties as natural gas and can be injected massively into the network, without any volume limitation.
About fifty Power-to-Gas projects are currently driven worldwide, Germany being the most active in the domain with several initiatives linked to this technology. In France, otherwise, hydrogen utilization and alternative fuel supply stations are mainly at the stage of demonstrators.
The deployment of these projects can be considered as a growth driver for the actors leading them: initiators of projects, Power-to-Gas specialists and industrial partners usually in association with public entities (research entities, institutions, associations and platforms, national agencies). According to their role and positioning on the various projects, these actors can stimulate and / or benefit from initiatives profitable to the whole French energy landscape:
New products and/or services development: strengthening of NGV or Bio NGV, renewable gas guarantees of origin certification, distribution of a new gas NG-H2 through the existing natural gas network …
Upgrading of innovative technologies: electrolyze, methanation, network management tools, production driving and hydrogen injection
Hydrogen transportation through the network under the NG-H2 form
Development of the French Power-to-Gas sector
Even though Power-to-Gas does not need any technological breakthrough (all the technical components are already available and efficient), the sector’s development would require a stage of processes’ industrialization as well as the implementation of a specific legislation and legal incentives in order to overcome the remaining profitability issues.
In a context of energy transition and strategic thinking on the French energy mix’ future, there is a strong interest from politics, scientists and economists on the Power-to-Gas related topics (storage, networks management, renewable energies’ integration). In 2017, the Power-to-Gas Club creation within the ATEE underlines such a commitment toward the development of this technology: the club aims to gather the actors from the sector and so, to support the projects’ deployment. The dynamism from this Club may stimulate the implementation of the necessary means to support the deployment of the sector.
[i] The steam reforming process the most spread process for the production of hydrogen. Although this method benefits currently from the economics factor, its cost remains higher than natural gas and requires the use of fossil energy sources emitting CO2 (natural gas, liquid fuels, coal).
[ii] H2 mobile - 2022
[iii] Mobilité Hydrogène France – 2016