Net-zero: Is the UK's gas grid ready to go green?
In a week where plans were unveiled for a nationwide roll-out of farming greenhouses heated by wastewater, the UK's major gas operators have teamed up to launch a programme aimed at delivering the world's first zero-carbon gas grid.
Heat accounts for more than a third of the UK’s greenhouse gas emissions and remains one of the biggest challenges for the nation to overcome as part of its transition to net-zero emissions by 2050.
While electric heat pumps and biomass boilers are common technologies across the UK’s housing stock and commercial buildings, most of the heat used by buildings and industries derives from fossil fuels. Natural gas – albeit blended somewhat with biomethane – is the “predominant source of heating for the vast majority of customers connected to the grid”, according to the Government’s own reports of the decarbonisation of heat. Around 75% of the UK’s current heating demand in buildings is met by natural gas.
The transition poses certain technological issues. The UK’s net-zero emissions target for 2050 will require every household to replace their heating system with lower carbon alternatives. It is estimated that this will take more than 1,000 years at the current rate, according to a Living Labs study.
Yet it could be argued that we’ve approached a breakthrough week for the transition to low-carbon heating and gas.
Firstly, the Energy Networks Association (ENA) has convened the UK’s leading gas operators such as Cadent, Northern Gas Networks, and National Grid to work on a Gas Goes Green project aiming to deliver the world’s first zero-carbon gas grid.
The Gas Goes Green programme suggests that with 85% of UK homes connected to the gas grid, prioritising decarbonisation in the heat sector would act as a cost-effective measure to help meet the broader net-zero target for 2050.
The programme will aim to use existing infrastructure while boosting new technologies. Hydrogen and biomethane have been highlighted by the collaboration as areas to accelerate progress.
The project will also leverage the expertise of the gas operators taking part.
Cadent, for example, has agreed to the UK's first 'transition bond' which has been issued to enable heavy-carbon emitters to access funds to decarbonise.
Cadent, which delivers gas to more than 11 million houses and businesses in the UK, has welcomed the UK’s net-zero emissions target for 2050 and is exploring the role that renewable gas can play in reaching the said target. The RIIO2 challenge group has praised Cadent for its informed and open approach to discussions on decarbonisation.
The company is leading on a fully operational pilot project that injects zero-carbon hydrogen into an existing gas network. Called HyDeploy, the pilot involves injecting hydrogen into Keele University’s existing natural gas network, which supplies 30 faculty buildings and 100 domestic properties. As a result, hydrogen will account for up to 20% of the gas mix in the network. HyDeploy claims this is the highest proportion being tested in Europe at present, given that existing UK legislation prevents hydrogen accounting for more than 0.1% of the national grid mix at any time.
Capturing waste heat and water is also viewed as an innovative way to deploy low-carbon heating solutions at scale.
One such example was announced this week. Low Carbon Farming is currently developing two wastewater-heated greenhouses in East Anglia and now plans to roll-out the infrastructure nationwide.
The greenhouses use heat pumps to capture waste heat from nearby water recycling centres and together cover 29 hectares of indoor growing space. The greenhouses use hydroponic growing systems that will use 10 times less water while increasing British tomato production by 12%. The associated carbon emissions will also be 75% lower than conventional measures.
Low Carbon Farming’s director Andy Allen said: “Our East Anglian projects provide British farming with a bankable template for the nationwide roll-out of transformative, renewable heat solutions. Having secured the financing and proven the business model, and with the case for secure and sustainable British produce having been thrown into such sharp focus, it’s time to plan for the next stage.
“Policy decisions made the innovation behind our first projects possible – specifically, the entirely logical extension of the Tariff Guarantee until the end of the Renewable Heat Incentive in 2021. We now look to government for a clear and far-sighted decision to extend revenue support for renewable heating in British farming far beyond 2021.”
The two current projects will cost £120m and are expected to create 360 new jobs, rising to 480 in high season. But Low Carbon Farming believes that a nationwide expansion of 41 greenhouses could create more than 8,000 new jobs, deliver £2.67bn into regional economies and increase the UK’s clean heat output by almost 3TWh per annum. It would also enable the UK to lessen reliance on imports of certain foods – emissions of which are not accounted for under the UK’s carbon reporting.
Low Carbon Farming’s East Anglian projects will supply British tomatoes to retailers including Subway and Sainsburys.
The company is working with Anglian Water to supply waste heat. David Riley, head of carbon neutrality at Anglian Water added: “These projects are helping us fulfil our environmental obligations and represent the kind of innovative approach to sustainability we are embracing right across our business in our own challenge to become zero carbon by 2030.
“Finding alternative sustainable uses for land close to water recycling centres which also make use of excess energy makes sense for UK businesses.”