Summary 

1. GRDF Takes Part in the Development of Renewable Gases …
2. How renewable gases benefit society and the environment
3. Transforming gas networks for renewable gas integration

In France, gas is the second most consumed network energy. Over 11 million individual, industrial, and local community customers use it for their heating, processes, mobility, and so on. Although most natural gas is still of fossil fuel origin, all players involved, most notably GRDF, Europe's leading distribution infrastructure operator, are concentrating on developing renewable, low-carbon gases. Given the acceleration of climate change, and to reach the "Fit for 55" roadmap's greenhouse gas emission reduction targets (55% emission reduction by 2030), renewable gases (biomethane in particular), have a vital role to play in tomorrow's energy system over the short, medium, and long term.

To illustrate the growing importance of renewable gases around the world, the International Energy Agency (IEA) devoted a chapter of its 2023 Annual Report to biogas and biomethane. It estimates that global production should increase fourfold by the end of the decade.

100% renewable gas by 2050 : On a nationwide scale in France, all forecasts suggest that renewable gases could account for 20% of French gas consumption in 2030 and for 100% of French gas consumption by 2050. GRDF plays its part in achieving this ambition through its commitments and its practical initiatives to promote the development of innovative production technologies. In its 2024-2030 strategic plan, GRDF intends to multiply by four its renewable and low-carbon gas volumes in its gas infrastructure by 2030.

Why is it important?

• Biomethane, a renewable gas produced through the anaerobic digestion of organic waste, the pyro-gasification of solid residue, and through hydrothermal gasification, emits 7 to 10 times less CO₂ than fossil-fuel gas. It is therefore a vital asset for energy transition.
• As it is produced locally, it supports the country's energy independence as well as regional and agricultural-community energy transition. 

How can we reach this target?

• By developing all renewable and low-carbon gas production processes on a large scale :
  biomethane and low-carbon gas obtained through anaerobic digestion (the most mature solution to date), pyro-gasification (a pathway that is ramping up to industrial scale), hydrothermal gasification and power-to-gas (P2G).
   

• By boosting energy sobriety efforts By 2050
  France could therefore have 320 TWh of renewable gases injected into its networks. According to scenarios, by this date, gas demand is estimated at between 200 and 334 TWh. The constant decrease, compared to the current consumption (381 TWh in 2023),can be explained, most notably by the progress made in energy efficiency and by the gradual adoption of more frugal practices. 

GRDF Takes Part in the Development of Renewable Gases

The gas sector has the ability to make France gas-autonomous by 2050. For more than 15 years, GRDF has been working in collaboration with many gas producers, such as farmers, industrial groups, communities, and technological partners, to contribute to developing and expanding this renewable gas production sector.

GRDF has conducted many R&D studies, supported new technologies, and cooperated with local and national associations to accelerate the injection of these new gases into the distribution network. GRDF can share its expertise with other gas infrastructure operators in other countries around the world.

By producing local, renewable gas

Since 2011, the year biomethane was injected into the French gas distribution network for the first time, capacity has grown at lightning speed. 

Anaerobic digestion, a biological process in which organic and/or plant matter is broken down when oxygen is absent, is also highly useful for recovering biowaste collected by communities. Transforming these resources into biomethane makes anaerobic digestion a circular economy model. 

More information on biowaste : “Biowaste, a key player in France’s circular economy and renewable gas production” (youtube.com)

Anaerobic digestion is a mature, effective process for producing biomethane. On 31 May 2024, 685 units were injecting biomethane nationwide, corresponding to 12 TWh, i.e. more than 2% of France's gas consumption and equivalent to the energy produced by two nuclear reactors. France boasts the world's largest number of biomethane facilities connected to a gas network.

With a range of services to support biomethane production

GRDF, a key player in France's gas chain, has developed in-depth know-how in rolling out agricultural anaerobic digestion for injection into gas networks. We work with farmers throughout the course of their projects, from assessing their biogas unit's future capacity in relation to the farm's own land-spreading plan to providing advice on using the digestate, and from building relationships with local communities to rolling out the procedures required for injection (odorizing, controlling gas quality, and metering).

In addition to agricultural anaerobic digestion, other types of infrastructures are being developed, particularly by local communities, waste treatment companies, and water treatment plants (anaerobic digestion from the decontamination of urban and industrial wastewater). GRDF shares its expertise with these different project holders to promote the development of biomethane production units and its injection into the network and, therefore, to help reach decarbonization targets. 

Our expertise is recognized in all operational aspects of anaerobic digestion projects:

• Upstream: planning anaerobic digestion projects with producers and local communities, carrying out feasibility/injection potential studies, connecting to the network, purchasing agreements, etc.
• Downstream: everything related to gas quality and metering so it is ready to be injected into the distribution network.

Our R&D teams constantly strive to improve the technologies used to support renewable gas production competitiveness (mobilizing and diversifying feedstock, improving the energy efficiency of biomethane production, etc.).

GRDF’s international activities throughout Europe and the world - GRDF.FR

And by supporting the development of new renewable gas production processes !

To ensure a 100% renewable gas mix in 2050, the production of network-injectable biomethane and low-carbon gas will come from various processes in the future. GRDF is working on the development of these new energy pathways, by ensuring technological and regulatory barriers are removed.

Our R&D teams are exploring the following decarbonized gas production pathways: pyro-gasification, hydrothermal gasification, power-to-gas, renewable hydrogen, etc.

Pyro-gasification: converting residual waste into energy, locally and sustainably

• Pyro-gasification is based on a thermochemical process where matter is converted at high temperatures (800 - 1,500°C), in the absence or deficiency of oxygen. It is used to transform a wide variety of solid residues, which are currently little or not recovered, into gas. Many different sources are used such as wood sector residues (not recovered as materials), scraps from furnishing items, sorting rejects of specific plastic waste, as well as solid recovered fuels (SRF).
• A French sector, supported by GRDF and GRTgaz, is ramping up to industrial scale. The first commercial industrial-scale unit projects for producing network-injectable, renewable, and low-carbon gas are currently emerging. 
• By 2030, pyro-gasification could recover around three million tons of waste per year, corresponding to the injection of 6 TWh of gas into networks and the reduction of about one million tons of the CO2 emitted.
• Our Company's role is to ensure this promising process is integrated into France's energy mix as quickly as possible.

More information on Pyrogasification : GRDF Green Gas : Pyrogasification (youtube.com)

Hydrothermal gasification: increasing waste recovery capacity 

• Hydrothermal gasification, still in a somewhat experimental stage, is considered as a complementary pathway for producing network-injectable syngas that have a high content of methane and hydrogen.
• Hydrothermal gasification is an across-the-board waste recovery technology used to recover a wide range of residues mainly of biomass origin, as well as waste of potentially fossil origin from a host of industrial and urban activities, therefore ensuring they are not landfilled or incinerated.
• It is based on a thermochemical conversion process that must be undertaken in the presence of water, under supercritical high-pressure (210 to 350 bar), and high-temperature (360 to 700°C) conditions. 
• Several demonstrator projects are underway in France. 

More information on Hydrothermal gasification : GRDF Green Gas : Hydrothermal gasification (youtube.com)

Power-to-methane: increasing waste recovery capacity

• Power-to-methane produces synthetic methane, also known as e-methane, by combining a water electrolysis stage to obtain hydrogen using surplus renewable electricity (also known as power-to-gas), with an anaerobic digestion stage where this hydrogen is combined with CO₂. This CO2 may come from biogas treatment (BioCO₂) or may be captured from industrial flue (fatal CO₂ from processes or combustion).
• In addition to direct hydrogen uses, anaerobic digestion generates gas that is directly injectable and storable in the gas infrastructure to decarbonize all residential, tertiary, and industrial uses.
• This renewable gas production sector is an effective driver for optimizing biomass recovery and, at the same time, provides additional flexibility to the energy system, for example, to recover renewable electricity produced over the summer. It also complements other renewable gas production sectors. Its role in balancing and completing the energy system has been identified in a number of forward-looking scenarios (ADEME "Transitions 2050" negaWatt 2022, etc.). This is why GRDF is involved in helping this technology gain ground in France. The first injection of synthetic methane into the gas distribution network was carried out by GRDF and the Energo start-up in July 2022 in Île-de-France. Other pilots and demonstrators, such as MéthyCentre, are also being rolled out.

How renewable gases benefit society and the environment

Biomethane and other renewable and low-carbon gases, already present at around 2% in France's gas distribution network, are set for a bright future. 

They bring numerous benefits for the climate, waste treatment, and the development of a circular economy. This is why stepping up the development of these gases is at the very heart of GRDF's strategy, with the Company intending to multiply the distributed volume of renewable gases by five by 2030. The goal is to reach 100% renewable gas in French networks by 2050.

Reduce greenhouse gas emissions 

An asset for decarbonizing regions and economies. 

• The carbon that plants store during their growth is recovered during the anaerobic digestion phase. The production cycle is carbon-neutral. 
• Anaerobic digestion captures methane that is released naturally as organic matter decomposes.
• This renewable energy's carbon content is only 44.4 gCO₂e/kWh LHV, versus 239 gCO₂e/kWh LHV for natural gas, according to Ademe's database. 

Reduce waste volumes significantly 

• Anaerobic digestion and other renewable gas production technologies have huge potential for converting all types of waste into energy. They prevent landfilling, which pollutes the ground, and incineration, whose energy potential is far less.

Produce local, renewable energy 

• Biomethane, produced by transforming organic matter that is forever renewed, is a renewable energy that is produced in the regions and used locally by customers thanks to existing networks. It is an asset for the country's energy sovereignty.

Boost farming sustainability 

Biomethane helps decarbonize farming and rural areas. 

• Anaerobic digestion produces renewable gas, as well as digestate, an organic fertilizer that farmers can spread on their farmland instead of chemical fertilizer.
• BioNGV (biomethane used for vehicles) can replace traditional fuels used in farming equipment.

Support local economy dynamism 

• The development of biomethane is an asset for the rural economy. Biomethane production diversifies farmers' sources of income. It creates local jobs that cannot be relocated and therefore preserves the network of farm holdings.
• On a nationwide scale, anaerobic digestion provides a way to establish a circular economy in the regions thanks to technologies that treat and recover biowaste (domestic, industrial, sewage sludge, etc.).

Promote existing infrastructure              

Biomethane flowing through the gas infrastructure is already a reality in France and the injection of other gases (e-methane, hydrogen) has been tested successfully. This illustrates that the existing natural gas infrastructure, and the qualified workforce that builds, operates, and maintains it, can safely supply cleaner molecules.

Ultimately, leveraging existing infrastructure systems and decades of French gas operators' expertise can facilitate the transition to a decarbonized energy system and make it more affordable for consumers, instead of starting anew.

Transforming gas networks for renewable gas integration

Gas infrastructure is profoundly changed when it integrates biomethane, which will help increase the amount of renewable gas in the network to approximately 60 TWh by 2030. As GRDF is committed to achieving 100% renewable gas in the networks by 2050, it utilises all its expertise for this transition, to make tomorrow's gas network safe, modern, and ready for use.

From a gravitation system to a system with multiple injection points

Biomethane production is, in essence, decentralized. France's 650 biogas units (total as of 31 December 2024) are spread nationwide. The historical gravitational flow of gas, i.e. upstream to downstream, from the transportation network through the distribution network and on to the customer. It is GRDF's responsibility to maintain balance by ensuring that the quantity of gas that flows through its network corresponds to the quantity of gas that will actually be consumed. Given its intention to maximize renewable gas injection, GRDF is investing in tailoring gas infrastructure and is a hub of state-of-the-art innovations.

Rolling out reverse flow to harness renewable gas potential

Gas consumption is strongly influenced by seasonality, but biomethane is continually produced throughout the year. Therefore, the distribution network is unable to absorb all the biomethane produced. What is the risk? That this wonderful local source of energy will not benefit anyone. Given the significant growth of biomethane in France, gas carriers and distributors had to quickly tailor their infrastructure.

Since 2018, gas infrastructure operators have been creating and setting up reverse flow stations. These facilities reverse gas flow and operate from downstream to upstream; they re-compress gas and "carry it up" from the distribution network to the transport network, therefore preventing network saturation and a decrease in biogas unit production. This technological breakthrough offers gas networks flexibility. By the end of 2023, 18 reverse flow stations were commissioned in France, which enables GRDF to improve its network's availability rate.

From a more general point of view, introducing reverse flow also brings new anaerobic digestion projects in regions to light. This technical solution is a real driver for making biomethane use more widespread.

Other solutions for temporary biomethane storage

In addition to these reverse flow stations (infrastructure projects that take several months to roll out), GRDF has developed Flores (Flexibilité Opérationnelle du Réseau in French, Operational Flexibility of the Network in English), an R&D project to enhance a network's operational flexibility. It comprises storage cylinders with a capacity of several thousand nm³ used to store the surplus biomethane produced in a compressed form. Thanks to the automatic compression/expansion system, the biomethane is quickly re-injected as soon as gas consumption takes off again. Therefore, when gas consumption decreases (at night or over the weekend, for example), production can remain stable and network balance is preserved. Flores facilities, located upstream of biomethane injection stations on production sites, are easy to install. They fulfil their mission perfectly by preventing network saturation.

Five initial units were set up in 2023 and two others were installed over July and August 2024. This is a scalable solution tailored to the specific needs of the grid; a temporary one as it is not intended to replace reverse flow but to make up for it when it is being rolled out, and a mobile one as it can be moved from site to site based on needs.

GRYHD: one of the 100% hydrogen network projects

GRHYD is France's first pilot project for producing hydrogen locally via electrolysis and injecting up to 20% into the mix with natural gas, in a new distribution network that supplies a district comprised of approximately a hundred dwellings.
The project, undertaken by 11 partners, was coordinated by Engie and benefitted from support from ADEME's Investments for the Future Programme and from the Tenerrdis competitiveness cluster. 

Project Timeline

GRHYD was used to assess and validate the technical and economic relevance of the mix for residential and mobility uses:

• Technical success in rolling out an elaborate power-to-gas chain.
• New distribution network and residential-tertiary gas uses working well with the H2/natural gas mix, under industrial safety conditions on a par with those of natural gas.
• Good social acceptability among users.
• Confirmed environmental benefits of injection (-8% eq. CO₂ vs. natural gas, reduction of CO and NOx emissions).

Given the complexity/benefit ratio, this pathway for recovering hydrogen and using it in networks has, however, been sidelined in favour of a strategy for developing new infrastructure and converting gas networks to 100% hydrogen.