Whilst the Prime Minister’s 10 Point Plan for a Green Industrial Revolution talks up decarbonisation of the gas grid, and therefore heat, with Hydrogen, it is far from clear that this will be the case. Unlike for electricity, there is no funded decarbonisation trajectory for gas nor any logical technological solution to achieving anything other than modest decarbonisation. For instance:
- To date only low levels of hydrogen, less than 20%, mixed into a localised gas grid have been demonstrated and newly installed boilers can only cope with up to 20% hydrogen;
- Current legislation limits hydrogen content to 0.1% of the natural gas grid, partially due to widespread prevalence of old technologies on the network that cannot handle higher;
- Expansive low carbon hydrogen generation is reliant on unproven scaled up processing of natural gas with Carbon Capture and Storage;
- A good case can be made that what hydrogen is generated should be used in hard to decarbonise sectors such as industry and transport;
- The additional process for generating hydrogen leads to questions of increased fuel costs, which may remove this current benefit over electricity.
The above constraints mean that whilst there may be a modest decarbonisation of the gas grid, it is hard to envisage it reaching the levels being achieved by electricity which is already on a pathway to further decarbonisation. Any major change for gas looks to be decades away and achievable only at high cost.
Heat strategies utilising electricity via heat pumps therefore remain a preferable strategy.