Gas companies have highlighted possible low-emissions replacements for gas, and yet these are a more costly, less certain, and less future-proof that electrification.
Proposals for gas replacements include methane made from organic waste (Biomethane), or hydrogen made using renewable electricity, referred to as Green Hydrogen. There are possible uses and benefits for these methods in hard-to-abate sectors, for example in emissions intensive industrial processes. However, at the household level they are significantly more costly and less immediately deployable than direct electrification.
Biogas generally refers to methane produced by the fermentation of organic matter. It is ‘renewable’ since it is produced by organic fuels like food and agricultural waste that will always be generated in perpetuity. Methane is a powerful greenhouse gas, capable of heating the planet by up to 100 times more than carbon dioxide in the short term. By capturing, then using this methane (which is inevitably created from decaying organic matter), this method can prevent these emissions from escaping to the atmosphere and exploit their potential to provide energy.
Despite its benefits and potential role in a future energy mix, biogas is not an alternative to electrification and energy efficiency. Capacity to scale up is limited and will take significantly longer than the simple deployment of existing efficient electric appliances and renewables; there is simply not enough biomass ‘fuel’ to generate the quantity of biogas required to replace our current usage of gas.
Likewise, clean or ‘electrolytic green hydrogen’ is an emerging technology that is likely to have a role in industrial production. There have been many suggestions as to how hydrogen can be produced as a fuel source. This includes an electrochemical process where hydrogen is separated from the source fuel. In this case, the carbon emissions would have to be captured and permanently contained. Other processes include electrolysis, which involves splitting water into its constituent elements of oxygen and hydrogen. Another suggested method is the use of electric heating systems, though the balance of the generation of electricity must be considered.
However, at the household level the cost and time required for deployment of renewables-generated green hydrogen far exceeds those of direct electrification. In practice, the renewables and transmission capacity required to produce green hydrogen for household use as a gas could more simply be used to directly electrify homes. Current modelling is showing that hydrogen-only scenarios will require twice the electricity requirements and higher costs than hybrid supply options of gas and direct electrification. Recent international research found that a green hydrogen heating system would be roughly ‘two to three times more expensive’ than one relying on electric heat pumps in both the EU and UK.
It’s not yet possible to buy or install a hydrogen-ready boiler.
Hydrogen: where is low-carbon fuel most useful for decarbonisation?
