As renewable resource infrastructure has burgeoned and prices fallen, consumers are increasingly opting for “100% renewable tariffs” from green energy suppliers. Renewable energy companies now account for 17% of the UK’s energy market, up from just 1% in 2011.
But despite the “100% renewable” label on the tariffs these companies supply, only their electricity is is coming wholly from renewable resources. The UK’s gas mixture, even that provided by green suppliers, remains overwhelmingly natural gas, some of it sourced from controversial and environmentally destructive fracking practices.
Renewable resources, mostly wind and solar, contributed 31.7% of the UK’s electricity in the second quarter of 2018, fetching headlines and relieving environmentally-conscious consumers. But progress in developing sustainable alternatives to natural gas have lagged behind wind farms and solar panels. Just 0.3% of Britain’s gas is renewable. That’s about to change however, as renewable suppliers and even gas giants invest in delivering ‘green gas’ to our boilers and stoves.
What sustainable alternatives to natural gas are there?
Natural gas is a fossil fuel. Burning it to heat our homes and dinners causes climate change. And as a non-renewable resource, it’s dwindling.
Today, the most viable sustainable alternative to natural gas is biomethane, popularly known as ‘green gas’ or renewable natural gas (RNG). It’s a naturally-occurring gas produced by the anaerobic (that’s without oxygen) digestion by bacteria of organic material—called biomass— including agricultural, industrial and food waste. This process occurs in green gas plants or mills, of which there are nearly 100 in the UK today.
Green gas is carbon neutral because it uses renewable sources, like plant material, that form part of the Earth’s existing carbon cycle. Burning green gas thus recycles existing carbon into the atmosphere, where it can be consumed by new plants as they grow. In contrast, natural gas introduces new carbon into the atmosphere that had previously been stored underground.
The production of green gas at green mills also doesn’t entail the carbon footprint and environmental damage of drilling and fracking. Additionally, it provides a use for existing waste that would otherwise end up in landfills, where it degrades and produces gases such as methane that are even more harmful to the environment than carbon. Reportedly, 16% of the UK’s methane emissions come from degrading manure, which can instead be used in green gas plants to produce carbon neutral gas.
The National Grid has estimated that 15% of the UK’s gas needs could be met with green gas produced by sewage, food waste from restaurants and supermarkets, and organic waste from businesses like breweries alone. And 50% of the UK’s residential gas demand could be met by the anaerobic digestion of existing biodegradable waste.
Green gas can be distributed via the existing gas infrastructure and used in your home for cooking and heating just like natural gas.
Who supplies green gas in the UK?
Renewable energy suppliers are mixing their natural gas supplies with increasing portions of biomethane, either generated in their proprietorial green gas plants or purchased from external plants. When you compare gas and electricity tariffs, you might want to consider the gas mix, and biomethane sources, of various suppliers:
- Ecotricity: supplies gas that is 14% biomethane; is in the process of building its own green gas mills to be fed by grass. Ecotricity, as the first vegan energy supplier in the UK, uses no animal waste to produce in its green gas.
- Bulb: supplies gas that is 10% biomethane, 100% coming from purpose-grown crops or food or farm waste. 0.4% comes from animal waste.
- Good Energy: supplies gas that is 6% biomethane, produced in the UK from manure and sewage.
What’s the future of green gas in the UK?
Expect percentages of biomethane in gas supplies to increase, as pressure to meet decarbonisation targets and stop climate change mounts. And renewable suppliers won’t be the only ones sourcing gas from grass. Gas giant Centrica, best known as the owner of British Gas and Scottish Gas, this summer bought a 50% stake in Barrow Green Gas, the UK’s leading biomethane producer, indicating a commitment to transforming their gas supplies.
And nearly 50 applications for new green gas plants have been filed with energy regulator Ofgem, representing an industry investment of £400m. Most will come online by 2020, bringing the total number of green gas plants in the UK to 146, from 98.