GMT: Scaling advanced biomethane infrastructure for a decarbonised energy system

What strategic model sets GMT apart in the biomethane sector?

GMT operates an integrated and standardized model, which distinguishes it in the UK market. We develop, construct, own, and operate our plants, allowing us to secure the entire value chain and optimize both technical and financial performance. Each site uses anaerobic digestion to convert agricultural residues and selected industrial organic waste into three main outputs:

• Biomethane: injected into the grid or sold to industrial and maritime customers.

• Renewable CO₂: captured and valorized for various industrial applications.

• Biofertilizer: stabilized digestate rich in nitrogen, phosphorus, and potassium, certified for agricultural use.

Unlike other developers who design each project individually, we have standardized nearly all aspects of our facilities: input supply agreements, site selection, engineering and procurement processes, construction partnerships, and end-customer arrangements. This approach streamlines and accelerates project replication while maintaining high operational and technical performance.

Our portfolio has grown rapidly, increasing from 3 to 13 projects since SWEN’s initial investment through the 3rd vintage of its SWEN Impact Fund for Transition, with a total CapEx of £400 million. Two sites are currently under construction or operational, three more are in planning, and the remainder are in development. We focus primarily on the East of England, a region rich in manure and poultry litter, allowing us to locate plants close to feedstock sources, minimizing logistics costs and associated emissions.

How have you built your strategy in the UK biomethane market?

We deliberately concentrated our investments in areas with high agricultural biomass density, to site plants near feedstock sources and reduce both logistics costs and emissions. The East of England is particularly favorable, with abundant manure and poultry litter.

The UK regulatory framework is also highly supportive of biomethane, with guaranteed tariff mechanisms funded by a levy on fossil fuel producers. This system provides long-term revenue visibility and facilitates project financing. At the same time, market dynamics have evolved rapidly: the number of projects, the interest from end-users, and institutional support have all increased substantially in recent years, creating a strong momentum for developing our platform.

Our commercial strategy has evolved accordingly over the past 18 months. Initially, we focused exclusively on specialist traders through long-term purchase agreements, often structured as Power Purchase Agreements (PPAs) or Contracts for Difference (CfDs), which allow us to secure biomethane prices and mitigate market volatility risk. More recently, we have seen growing demand from end-users, particularly in maritime and industrial sectors, seeking biomethane to decarbonize their operations from 2028 onwards. These agreements are tailored to volumes and consumption schedules, enabling us to capture value above standard market prices.

What do you value the most in SWEN’s partnership ?

The partnership with SWEN has been pivotal in implementing our distinctive “design-build-own-operate” model, particularly given GMT’s proprietary technology that requires high technical expertise. Designing and sizing digesters, precisely controlling feedstock flows, and valorizing by-products demand a deep understanding of the sector and operational realities. SWEN’s technical and field experience enabled them to objectively assess our technology and support our expansion strategy—something that would have been difficult with less specialized investors.

Through this partnership, GMT has transitioned from a developer-for-others model to deploying a robust platform capable of:

• Standardizing projects to reduce costs and risks,

• Securing the full value chain,

• Replicating projects at scale across the UK.