Last Updated on 18/07/2022

What is Green Gas?

Biomethane, otherwise known as Green Gas, is a gas mixture consisting predominantly consisting of methane. It has similar thermal characteristics to natural gas. Subject to meeting gas quality requirements biomethane is considered as pipeline quality gas and can be injected into the natural gas network and used in existing gas appliances.

How is Green Gas produced?

Step one in the manufacturing process is to collect Biomass – a variety of organic materials, including the biodegradable fraction of domestic and commercial wastes (e.g. food waste, paper, card and wood, agricultural waste, sewage sludge, energy crops, residues from whisky distilling and cheese making).

Step two is to place this biomass into tanks where bacteria breaks it down naturally in an oxygen-free environment in a process known as anaerobic digestion (AD). This is the same process that occurs in a cow’s stomach, but while cows burp methane out into the atmosphere the gas produced at AD plants is collected (at this stage known as biogas). Fertiliser is another by-product of this process. Biogas is a combustible gas composed predominantly of methane, carbon dioxide, and other trace levels of hydrogen sulphide, water vapour, ammonia.

At the end of this collection stage, the unpurified biogas can be burned on-site to generate heat, power or both. Or it can be purified to make biomethane, or Green Gas (see step 3 below).

Step three involves the use of a biogas upgrader facility to remove all elements of the biogas other than methane, thereby purifying the biogas up to the levels of methane concentration required to be interchangeable with natural gas (i.e. biomethane gas). One technique for doing this uses amine gas treating. There are four main methods of purifying the biogas, the most popular being water washing. This involves high-pressure gas flowing into a column in which the carbon dioxide and other trace elements are scrubbed by cascading water running counter-flow to the gas. This arrangement can deliver 98% methane with manufacturers guaranteeing maximum 2% methane loss in the system. It takes roughly between 3% and 6% of the total energy output in gas to run a biogas purification system.

Why is Green Gas more eco-friendly than natural gas?

If left to escape into the atmosphere, methane is over 20 times more potent as a greenhouse gas than CO2. Capturing and burning it instead as Green Gas releases the same amount of carbon than the organic matter originally absorbed, meaning no net negative impact on the climate.

Biomethane as a vehicle fuel, known as bio-CNG, delivers all the benefits of natural gas, but with clear advantage; it is renewable and sustainable. Compared to diesel, there is around 72% reduction in CO2 emissions. There are significant economic benefits for fleet owners switching to natural gas vehicles, with financial savings of between 40% – 50% compared to diesel.

The UK government is on record as saying: ‘Biomethane-to-grid is a key renewable technology that has the potential to make significant contribution to the UK’s 2020 renewable energy commitments’. This means that the biomethane-to-grid sector has significant government support. It supports the AD industry via the Renewable Heat Incentive and places strict sustainability criteria on the biomethane production process. This ensures that any crops used as feedstock cannot be grown on land that has been converted from valuable natural habits, and that the production process has a carbon footprint 60% lower than the European average for emissions from heat generation. Many producers achieve reductions well in excess of 60% and AD plants also provide a valuable method for dealing with organic waste products, while generating a high-quality fertiliser than is used by farmers around the UK.

How well developed is the existing UK Green Gas supply infrastructure?

The Renewable Heat Incentive for biomethane, set up in 2011, helped create an attractive regime to allow biomethane-to-grid innovation to flourish. Biomethane engineering specialist, CNG Services, worked with gas distribution network companies to find practical ways to connect small producers to the gas grid, and these efforts culminated in the first commercial connection at Rainbarrow Farm, Poundbury in 2012. This is owned and run by J V Energen, a joint venture between local farmers and the Duchy of Cornwall, was Britain’s first AD plant to inject biomethane into the gas grid. Biogas production began in March 2012, with commissioning of a 400 kW CHP plant, with injection to the gas grid commencing in October 2012. The annual raw gas production is around 7.5mn m3 (mcm).

Since that point, and particularly from 2014 onwards, the UK has seen the highest levels of biomethane-to-grid connections growth in the world. To date, there are approximately 80 plants across the UK injecting renewable biomethane into the grid, the largest (food waste) being ReFood in Widnes.

Biomethane plants are like wind turbines and solar farms in terms of how they can receive renewable guarantees of origin for their gas production. These form the basis of Green Gas Certificates that can be purchased by households and businesses to show that they are using biomethane or ‘green gas’.

The Green Gas Certification Scheme (GGCS), run by Renewable Energy Assurance Limited, issues Renewable Gas Guarantees of Origin (RGGOs) for an increasing number of biomethane producers in the UK. Running since 2011, the GGCS ensures that there is no double counting in the supply chain, so when a household or business consumer buys a GGCS Green Gas Certificate they can be assured that units of biomethane have been injected into the grid that match the units of gas they are consuming.

The GGCS has worked with Greenhouse Gas Protocol (GHGP) to show how companies using the GHGP accounting methodology can report close to zero Scope 1 CO2e emissions when evidencing their using biomethane use with a GGCS Green Gas Certificate. More details on emission reporting are available via the GGCS website and Jesse ([email protected]) on the GGCS team is happy to receive enquiries about the Scheme and provide the latest information on the green gas market.

In addition to the GGCS, many of the green gas suppliers are ISCC accredited (International Sustainability and Carbon Certification). This is a globally leading certification system covering the entire supply chain and all kinds of bio-based feedstocks and renewables. Several Green Gas suppliers/shippers can now deliver green gas to continental Europe as well as the UK via a European partner network.

There is huge potential to scale up UK biomethane production in the future; currently, just over 2 million tonnes of food wastes (out of 16 million tonnes generated each year) and less than 1 million tonnes of manures/slurries (out of 90 million tonnes generated each year) is being anaerobically digested.

How much demand is there for Green Gas in the UK?

Around 75,000 UK households are currently being supplied with up to 100% green gas. A survey conducted by the Renewable Energy Association (RHA) has found that 84% of people in the UK would like to switch to using Green Gas in their homes; 55% of people are prepared to pay more to switch to a green fuel. The RHA has estimated that green gas could produce as much as 25% of the UKs equivalent natural gas imports by 2035. And the National Grid has estimated that biomethane can supply 5%-18% of Britain’s gas demand by 2020. This make a significant positive contribution to the Climate Change Act target of an 80% reduction in greenhouse gases by 2050. Having an alternative domestic gas supply also supports our energy security as it reduced our dependency on imported gas supply.

A growing number of businesses are using green gas to support their carbon reduction plans. Sainsbury’s is powering some of its stores with green gas and Waitrose has started to move from diesel to biomethane in its haulage fleet. IKEA has launched a project to make plastic for its furniture from biogas.

There is also a growing demand for the Green Gas Certificates provided to businesses who want to demonstrate they operate sustainably. This rising demand has been underpinned by a change in emissions reporting, which means companies can report near zero GHG emission for Green Gas used onsite.

Interested in sourcing Green Gas for your business or household?

We hope this blog has shown you why green gas is eco-friendly, resulting in a massive surge in demand and rapidly expanding supply infrastructure to meet it. So the key question is – how can your business or household join the UK energy revolution, enabling you to demonstrate your commitment to operating sustainably?

The great news is that, through its green gas supply broker partners, are now ready to offer your business or household the ability to receive green gas supply. We would be delighted to facilitate the supply of competitively priced green gas to any business that are looking to reduce their reported emissions.

To proceed without obligation, CLICK HERE where you will be sent to a page asking you to complete a short enquiry form. Once we receive this, we will be in touch to guide you on your journey to becoming more sustainable in your energy consumption.

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