Operating and maintaining

Since 2014, we have helped optimize the performance of biomethane plants. To do this, we offer services that leverage all operational drivers requiring concurrent management.



As organic waste experts, we bring together waste producers and short-circuit plants to recycle waste and benefit the country as a whole.


Let’s design your project together

Biomethane projects: the five key elements

To ensure that any biomethane plant is feasible and will stand the test of time, it is vital that the project meets the following five criteria related to the site.


terrain à bâtir

Technical expertise is required to identify the ideal site for a biomethane plant that takes into account these three factors.
Consider the location of the site in relation to the region as a whole, paying attention to existing infrastructure, feedstock sources and gas pipelines.

Take note of urban planning documents and protected areas
Check if the land is subject to ICPE regulations (French environmental protection rules).
Economic viability
Verify that the plot is serviced, or that it can be (road access, electrical grid, drinking/waste water, telephone lines).
Carry out a geotechnical investigation (analyse the properties of the soil to plan for any processing or laying of foundations).


poste injection

To ensure that any project is both profitable and long lasting, we have identified the different methods currently available for reusing gas obtained through the digestion process.
• Reuse via injection or cogeneration.
• Feasibility study carried out with the gas network manager (length of pipeline/connection cost/injection capacity/competition with other projects in the same region)

• Use of gas co-products: resale of biogenic CO2, creation of a bio-CNG station, reuse of digestate, etc.
• Gas purchase price: monitoring the gas market and the most advantageous gas pricing mechanisms for the project, e.g. purchase obligations, gas certificates and BPAs (Biogas Purchase Agreements, which enable the direct sale of biomethane and biogenic CO2 to consumers).

Feedstock sources

Feedstock is essential to the biomethane process. KEON subsidiary TEIKEI specialises in identifying all available feedstock sources in the surrounding area to feed your future biomethane plant.

Our feedstock expertise covers:
• Researching materials
• Price guarantees
• Quality and plant suitability guarantees
• Traceability guarantees

Transparent pricing and negotiations
• Securing of feedstock sources (contract agreement to ensure a steady supply of material).
• Supply logistics: local distribution channels within a maximum radius of 200 km.
• Tax exemptions for manufacturers.
• Administrative management.


To ensure the success of the project, it is vital to think ahead about the best methods of using the digestates produced.
Setting up and monitoring a spreading plan: researching plots of land, initial analysis of soil condition, establishing the project’s spreading plan, continuous monitoring of the plan while the site is in use, including soil analyses and reporting on spreading (which digestate and how much, which plot, etc.).

Aside from being used for spreading, digestates are not necessarily classed as waste products thanks to DIG specifications (CDC Dig, formerly DigAgri) approved by the 22/10/2020 ministerial decree. This means that CDC Dig-compliant digestate is classed as a fertiliser and can be sold to the general public or to third-party organisations.


Any biomethane plant is directly connected with the region where it is located. It should benefit the region as a whole. Fostering the support of local stakeholders and residents is essential for the success of the project. This means communicating, informing and explaining the role played by the biomethane process and the impact that the plant will have on the local ecosystem.

We can assist with the following steps in the local area:
• Attending meetings with the Mayor and the local council, the community of municipalities and, more broadly, regional authorities and devolved state services
• Organising and running public information sessions as well as Q&As and educational talks

with experts, biomethane plant operators, farmers, representatives from GRDF (France’s main natural gas distributor) and more
• Creating communications materials about the plant: website, brochures, flyers, etc.
• Publicising and promoting every step in the process, from laying the first stone to the first gas injection into the grid, to the launch, open-house events and more
• Ensuring a TER’GREEN spokesperson is on hand for conversations and discussions with and questions from citizens.

Setting up a project team

To ensure the best possible environment for the success of the project and a clear decision-making process, we organise management committees that meet on a weekly basis. We can help you establish any new roles required and lay out the responsibilities of each one.

Assembling partners to achieve a common goal

We bring together stakeholders who are not necessarily known to each other: farmers, local communities, GRDF (France’s main natural gas distributor) employees, French Chambers of Agriculture, manufacturers, funding bodies, banks, local authorities and more.

Allocating responsibility

How will decisions be made and who decides on what? These are key questions when it comes to moving forward with any project and the answers are particularly important to funding bodies. A clear organisational structure will always reassure banks.
To assist with this process, we can draw up a partnership agreement governing the actions of each shareholder by specifying the organisational chart of the simplified joint-stock company (SAS), its chief executive, the executive team, the shareholder representative, the General Meeting schedule, etc.

Ensuring progress through regular meetings

During the development phase, we set up weekly steering committees to ensure the project moves forward at a reasonable pace and that everyone is aware of progress made. The aim of these committees is to review the latest information available, outline next steps and ensure the schedule and deadlines are respected.

Identifying and bringing together key stakeholders

Conducting techno-economic feasibility studies

Drawing on more than 15 years’ experience and the expertise of our fellow subsidiaries, we can put together a realistic business plan that includes capital expenditure (CapEx) and operating expenses (OpEx) based on actual market prices to avoid any additional project costs. This plan will change as the project evolves and can be adapted to ensure the business is profitable and stands the test of time. Finally, it can be used as part of a bank application or subsidy request application.

Optimising project design for maximum profitability while taking into account any operational or maintenance challenges. We plan for possible changes right from the get-go.

Having consulted with project partners and local residents, we put together the planning permission application file, submit it to the authorities and track the administrative process to ensure the project remains on schedule.

We file an ICPE (installation classified for the protection of the environment) spreading authorisation request based on a detailed study of the site and the wider area. The application describes the project and any effects it might have to ensure smooth integration within the region and minimal environmental impact.

In order to process the maximum amount of organic waste from the surrounding area, we submit a health and safety approval request for processing animal waste (livestock manure, agri-food industry waste). This process necessitates a detailed analysis of waste composition and traceability.

Securing success through five key elements

Alongside the submission of regulatory authorisation requests, we also take care of the five elements that are key to the success of any project:

The land

We secure a preliminary sales contract or an agreement to sell.


By securing a biomethane injection contract and a connection contract with the grid operators, we ensure that the biogas produced by your plant will be used.

Feedstock sources

We secure at least 70% of the plant’s production capacity (biogas flow) with the help of our subsidiary TEIKEI, which specialises in the sourcing and supplying of feedstock.


Digestate spreading in line with spreading agreements.


Throughout the development phase, we consult and communicate with residents to ensure the project is well received by all regional stakeholders.

Ter’Green benefits


We work efficiently to move your project forward and ensure timely completion.


We ensure you can secure loans thanks to our in-depth knowledge of the banks’ criteria.


We draw on the skills of our subsidiaries at each stage of the project (design, construction, maintenance, operation).


We ensure the project remains financially viable, despite external risk factors (raw material price hikes, fall in buy-back prices).


To date, 100% of the projects we’ve worked on have been successful.


We commit to partnering with you at every stage of your project to ensure its success.


We help you save time thanks to our comprehensive understanding of your project.


Any biomethane project is a complex undertaking. We spur on the stakeholders involved in the project and ensure their continuous development.


We join all projects at all stages, from those that are just getting started to those in the development phase and those that are already in operation.

Get in touch

Call us

Need help or have a question about your biomethane project? We're available from 8 am to 6 pm, Monday to Friday. Feel free to get in touch if you need our help.

+33(0) 1 57 21 34 70

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Want to meet us in person? 
You can find us at 52 rue Paul Vaillant Couturier - 92240 Malakoff or at 3 Rue Galilée - 44 340 Bouguenais

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