Green Gas Support Scheme (GGSS): open to applications
Source: gov.uk (2025-12-10)

This scheme provides tariff support for biomethane produced via anaerobic digestion which is injected into the gas grid.

Update: 10 December 2025

New regulations are expected to come into effect in early 2026 to extend the commissioning deadline of the Green Gas Support Scheme (GGSS) from 31 March 2028 to 31 March 2030. While this extension will be subject to the standard parliamentary scrutiny, the aim is to provide new applicants with an additional two years to commission plants, begin injecting biomethane into the gas grid and make their stage 3 application for GGSS registration. The proposed extension aims to maximise deployment and the associated carbon savings that can be achieved through the scheme.

The deadline for submitting new stage 1 applications will remain 31 March 2028. Under the current regulations the standard tariff lifetime is 15 years but if participants commission beyond 31 March 2028, their tariff length will not be extended and will end by 31 March 2043. For example, if an applicant has a commissioning date of 31 March 2030 (the final date possible under the extension), they would receive a tariff lifetime of 13 years.

Applicants who applied before 10 December 2025 will need to retain their original commissioning date. If this is not achievable, they may choose to withdraw and submit a new application. Please note that re-entry will be subject to the scheme’s eligibility criteria and conditions at the time of reapplication and is not guaranteed.

Applicants who submit stage 1 applications on or after 10 December 2025, but before the proposed regulations come into effect, must apply with a commissioning date no later than 31 March 2028. If the commissioning deadline becomes unachievable for an applicant in this category after the proposed regulations come into force, the date may be revised to a later date (no later than 31 March 2030) without the applicant needing to withdraw or reapply, provided they meet the necessary requirements under the regulations.

The Green Gas Support Scheme (GGSS) provides tariff support for plants producing biomethane via anaerobic digestion which is injected into the gas grid. Tariffs are calculated to compensate plants for the building of new infrastructure to produce biomethane and ongoing operation costs.

It is funded by the Green Gas Levy (https://www.gov.uk/government/publications/green-gas-levy-ggl-rates-and-exemptions) which is applied to all licenced fossil fuel gas suppliers.

The scheme follows the Non-Domestic Renewable Heat Incentive (RHI) Scheme (https://www.gov.uk/non-domestic-renewable-heat-incentive) which closed to new applicants on 31 March 2021.

The GGSS opened on 30 November 2021. It is open to applications until 31 March 2028, following the mid-scheme review (https://www.gov.uk/government/consultations/green-gas-support-scheme-mid-scheme-review) which extended the scheme closure deadline from 30 November 2025.

Registered participants will receive tariff payments for up to 15 years.

How to apply

You can apply on Ofgem’s Green Gas Support Scheme portal (https://ggss.ofgem.gov.uk/)

Find out more about the scheme (https://www.ofgem.gov.uk/environmental-and-social-schemes/green-gas-support-scheme-and-green-gas-levy) and read the scheme guidance (https://www.ofgem.gov.uk/publications/green-gas-support-scheme-guidance) on the Ofgem website.

Tariffs and budget management

Two separate budget caps have been set for the scheme:
- the Applications Budget Cap (ABC): a cap against which applications to the scheme are checked to ensure that there is available budget based on their estimated production and resulting spend
- the Overall Scheme Expenditure Budget Cap (OSEB): set above the ABC, this cap directly correlates to levy collection
Visit the Green Gas Support Scheme budget management (https://www.gov.uk/government/publications/green-gas-support-scheme-budget-management/green-gas-support-scheme-budget-management) page for budget cap details.

Tariff review

The Annual Tariff Review is the primary mechanism to amend tariffs offered to new applicants. The review ensures the scheme continues to meet its objectives and consistently delivers value for money. The outcome of the Annual Tariff Review will be announced annually in the autumns of 2026 and 2027 with any change taking effect at least one month after the announcement.

The degression mechanism on the GGSS acts to prevent over-compensation where biomethane deployment is greater than anticipated. It will do so by automatically reducing the tariffs available for new applicants by 10%, if set expenditure thresholds within a quarter are expected to be exceeded.

Expected outcomes

The scheme will help decarbonise Great Britain’s gas supplies by increasing the proportion of ‘green’ gas in the grid. During peak years of production, biomethane plants incentivised by the GGSS will produce enough green gas to heat around 250,000 homes. The GGSS is expected to contribute 4.4 million tons of CO2 equivalent of carbon savings over Carbon Budgets 4 and 5, and 10.7 million tons of CO2 equivalent of carbon savings over its lifetime through the displacement of natural gas in the gas grid. We expect the GGSS to help support high quality jobs in the renewable energy sector, at a time when economic recovery is so important.

Related links
- We consulted on the GGSS in our April 2020 Future Support for Low Carbon Heat consultation (https://www.gov.uk/government/consultations/future-support-for-low-carbon-heat). We published the government response in March 2021 and the final stage Impact Assessment in September 2021.
- We consulted on the mid-scheme review of the GGSS in March 2023 in the Green Gas Support Scheme mid-scheme review consultation (https://www.gov.uk/government/consultations/green-gas-support-scheme-mid-scheme-review), and published the government response in January 2024.
- GGSS Digestate Management Consultation (https://www.gov.uk/government/consultations/green-gas-support-scheme-ggss-digestate-management)
- GGSS Budget Management Notice (https://www.gov.uk/government/publications/green-gas-support-scheme-budget-management/green-gas-support-scheme-budget-management)
- Methods of calculating greenhouse gas emissions (https://www.gov.uk/government/publications/methods-of-calculating-greenhouse-gas-emissions)