Green Gas FAQs

We believe most businesses will go through a similar process when looking to build a strategy to reduce their emissions.

1. Elimination and Reduction - The first considerations should be where existing emissions can be reduced or avoided. Firstly through reduced energy consumption, and secondly through increased energy efficiency.

2. Substitution - Once a business has eliminated and reduced emissions where possible, they can then look at where alternative methods or energy sources could replace what is currently in place. An example would be using unsubsidised biomethane to replace fossil-based methane or for industrial processes with a high heat demand. Another example might be through electrification.

3. Mitigation - After a business has eliminated, reduced and substituted, they can look at mitigating any remaining emissions. Given the varying quality and transparency of the options available in this market, businesses are best advised to look at high integrity solutions that involve the active removal of atmospheric CO₂. This is where our carbon removal solutions can be utilised.

Anaerobic digestion is simply when organic materials are broken down by microbes in the absence of oxygen. This is a process that occurs naturally such as in the stomach of a cow.

This is covered in more detail in our dedicated page.

Scope 1 emissions are those that occur from sources that are directly owned or controlled by the company. It includes emission from combustion, process emission and fugitive emissions.

Biomethane delivered physically, or virtually via the gas grid, can be used to cut Scope 1 emissions. However, for the latter, the GHG Protocol (GHGP) is currently reviewing the role of market-based reporting across all Scopes, which includes the ability of companies to report the use of biomethane extracted from a shared gas network. Nevertheless, both the UK Government and European Commission are actively developing policy which uses market-based reporting to support a growing biomethane sector.

The UK Emissions Trading Scheme (ETS) represents the country's primary compliance market. However, under this scheme, biomethane can only be used to reduce your emissions if consumed on a physical basis i.e. delivered by a direct and dedicated pipeline. However, UK ETS Authority has stated its intention to permit companies to report emissions savings delivered from biomethane extracted from the grid.

Within the voluntary market, the Greenhouse Gas Protocol (GHGP) represents the leading reporting framework used worldwide. This framework is administered by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD), and its guidance is largely followed by the Science-Based Targets Initiative (SBTi).

The GHGP is in the process of reviewing the market-based reporting across all scopes. This includes the ability of companies to report Scope 1 emission savings from the use of biomethane extracted from a grid. Biomethane operators across Europe are collectively recommending its inclusion.

With unsubsidised energy, the end user is covering the full cost of energy generation. Consequently, they may claim full responsibility for the associated carbon savings. This energy, and its carbons savings are considered 'additional' - i.e. they would not have been delivered without the transaction.

By comparison, subsidised energy is funded, in part, by taxpayers. Government subsidy schemes may fund production regardless of specific end users. Consequently, there are growing concerns of greenwashing, where private companies are claiming to decarbonise by using renewable energy that was actually funded with public money, and so their contribution to, or their responsibility for those carbon savings will only ever be viewed as partial at best.

Today, the UK uses around 1,000 TWh of fossil natural gas per year. To deliver Net Zero, this demand must be cut significantly. Renewable electricity technologies (wind, solar, etc) can help replace gas-fired generators, low grade heat can be electrified, gas exports can be limited, and efficiencies can be improved across operations.

However, certain gas uses will be unavoidable – they cannot be reduced or replaced. This might include processes which require intense heat, require gas’ chemistry, and/or relies on fixed infrastructure. The UK’s unavoidable gas demand is modelled to be between 85 and 250 TWh.

Green gas is essential to decarbonise this unavoidable gas demand. Biomethane is the only solution which is currently produced and transported across the UK at scale.

The gas grid acts like a country-wide battery – storing energy within its molecules and delivering it when and where required. Consequently, the grid acts to balance our energy network, offering flexibility to its users. It can be used to heat homes, fuel industries, or generate baseload electricity. As the UK increasingly depends on intermittent electricity generators, such as wind and solar, the gas grid can help ensure power supply when the wind isn’t blowing and the sun isn’t shining.

While our project is new, we have a landmark partnership with AstraZeneca, detailed here.

Our model focuses on three pillars: Food, Fuel & Farm Decarbonisation. By working with farmers already looking to employ sustainable methodologies and by using break crops within food rotations, we believe our model is very sustainable.

While we believe waste-based AD is an important part of the sector, this is reliant on the waste being truly unavoidable. The reduction of waste is even better than recycling it. Once waste becomes a commodity, its production can potentially become incentivised.

For biogas to fulfil it's full potential in terms of its overall contribution to decarbonising the gas grid, a wide variety of feedstocks will be required. These include unavoidable food and agricultural wastes, in addition to rotational crops.

We believe the 'food vs fuel' debate can reinforce a misconception that land always serves a single purpose (eg. a field can either grow food crops or energy crops). The reality is that each field's output can change from season to season, delivering a broad range of socio-economic and environmental benefits.

Our approach relies on a move away from conventional, intensive farming. Using crop rotations, AD can be sustainably integrated into agricultural systems, with minimal impact on total food production. Break crops can be fed to AD, providing a source of home-grown, low-carbon energy, benefiting energy security and decarbonisation efforts.

Spreading the resultant digestate (AD's organic biofertiliser that is the solid and liquid feedstock remnants) back to land can help replenish soil carbon and displace demand for carbon-intensive artificial fertilisers.

When compared to other renewable energy sources in terms of land usage change (such as solar farms for example) AD is far easier to fit within and in partnership with existing food production models.

We believe our model delivers food AND fuel.

We recognise that not all businesses have huge gas demand and we believe this shouldn’t exclude you from accessing this method of decarbonisation.

To help us bring a more accessible offering to market, we have partnered with ENGIE to offer smaller increment offerings. In minimum increments of approximately 10GWh, we can divide the output of an AD plant to meet your demand.

Project Carbon Harvest is the UK's first unsubsidised biomethane project. The availability of unsubsidised gas offtake is limited to the volume of gas produced by our new generation of AD plants.

While we are in the planning stages of a number of new sites, and will continue to plan new sites in the coming years, signing up now ensures your gas demand can be covered by those sites already in planning.

The planning and construction timeline for new sites can be influenced by many factors. By signing up now, this timeline from your perspective can be significantly reduced. Particularly if (as we expect) changes in UK ETS create sudden boom in demand for unsubsidised biomethane in the near future.