The new Energy System Catapult study of Net Zero energy technology options sees electrification as a critical part of UK energy system decarbonisation. It has final energy consumption across its scenarios ranging from 525TWh/yr to 619TWh/yr by 2050- double the size of UK power today. But it says low carbon technologies can meet demand by 2050- with their contribution being a significant increase on earlier iterations of its analysis, reflecting they say ‘greater confidence in clean power technologies’. And it’s also seen as being affordable: the report puts the cost of the transition within 1% of GDP by 2050’.
However, it says that big changes have to be made, with it now being clearer which options to focus on. It says it will be essential to accelerate the deployment of key mature technologies such as offshore wind and solar, large-scale nuclear, heat nets and the electrification of home heating via heat pumps. In parallel it says the UK needs an accelerated programme of innovation in novel less mature technologies like small modular reactors, long duration energy storage, and bioenergy with carbon capture & storage (BECCS) and also direct air capture and storage (DACCS). It also says that fossil CCS ‘is essential for industry to meet Net Zero at least cost’.
It lays out an expansion programme up to 2050, with between 33GW and 76GW of offshore wind being installed by then, providing up to 53% of all UK electricity production. Solar goes up to 11% from between 19GW and 70GW, while nuclear would supply 20% by 2050, with between 23GW and 31GW being installed by 2040, and nuclear also supplying heat and hydrogen. Although it will be a challenge, some of that is not contentious, and it’s good to see that onshore wind is also included. But not everyone will agree with nuclear, large or small, or see BECCS or DACCs as viable at large scale.
The report however sees nuclear power generation as ‘a significant contributor to UK electricity production in all our Net Zero energy system designs, providing over 20% of annual electricity generated by 2050’. Both large scale and small modular nuclear are seen as viable, with up to 16GW of small modular reactors built by 2050. It also says that there is ‘potential system value in nuclear cogeneration of both heat, via heat networks, and hydrogen production’ and concludes ‘there is an urgent need to accelerate development of small modular reactors and cogeneration nuclear plant which are currently at lower levels of technology readiness’. With no SMRs in existence anywhere yet, much less cogen plants, that is a bit of an understatement!
The report also says that ‘biomass is consistently an integral part of our future energy system across all our scenarios’. Certainly the production of biogas from wastes can play a helpful role, but there can be environmental problems with some uses of biomass, with, for example, the use of imported wood pellets as a source of energy being contentious. The report however says that ‘the potential for bioenergy to deliver negative emissions when combined with carbon capture & storage has significant value.’ In reality that is very speculative: fossil CCS has been very slow to develop, so BECCS is still a long-shot option, with there also being major land-use issues if it was attempted on any significant scale. And there are also issues with DACCS- it’s an energy intensive process.
Overall the Energy System Catapult’s modelling suggests ‘biomass consumption of between 108TWh/yr to 174TWh/yr by 2050 for hydrogen production, industry, power generation and synthetic fuel production.’ That’s even more speculative- and its plan seems to involve mainly blue hydrogen from fossil fuels with CCS (up to 28GW) and pink hydrogen from nuclear (up to 14GW), not green hydrogen from renewables, apart from up to 4GW of biomass generation. That’s a pity- for example there are some interesting plans for producing green hydrogen for industry.
On the home heating side, along with heat pumps centre stage, it’s good to see heat nets and CHP still in there, but it says ‘it is unlikely that hydrogen will play any significant role in heating buildings in the future. Electrification of heating in most buildings remains the most cost-effective pathway to Net Zero.’ However, it does looks to hybrid heating systems combining heat pumps with fossil gas-fired boilers. That’s ‘to avoid stifling the roll-out of low carbon technologies such as EVs and heat pumps while we are upgrading and expanding the electricity network and also to provide resilience in extreme weather events during that transition’. Quite an admission: we can’t use green hydrogen, but heat pumps may stress the grid and also not always be up to supplying enough heat!
It’s not surprising then that says that ‘natural gas will be needed in a transition role providing back-up power generation and heat in homes and buildings over the coming decades. It will also likely be a significant source of energy for hydrogen production technologies and DACCS.’ However, it does add there will be ‘a significant overall reduction in gas use compared to today, which will have implications for gas network use’.
It does seem a bit odd that, while outliers like SMRs, BECCS and DACCS are front and centre, green hydrogen production via electrolysis using excess wind and solar power is mostly ignored, while the use of fossil gas is condoned for back up- as well as for hydrogen production. ‘Our modelling finds system value in the use of hybrid heating systems combining electric heat pumps with the supply of gaseous energy (natural gas) through the existing gas network, as we transition the system’. But is does say that ‘alternatives to meeting the ‘peak heat’ challenge, such as increased use of combined heat & power, more rapid reinforcement of the electricity grid combined with increased generation and long duration storage (both gaseous & electrical) all need to be explored & tested.’ Well yes, CHP, heat storage and, dare I say it, green power-to-gas hydrogen conversion and then storage, can all offer a way to balance variable renewables and peak demand.
The report does seems loath to embrace green hydrogen in any sector, and mainly sees fossil fuel-derived or nuclear-derived hydrogen and other synfuels being used in industry and for some transport, such as off-road heavy-duty vehicles. Although it says while ‘electrifying cars and light duty vehicles are low regret options to pursue for 2050’, alternatives such as the ‘widespread use of hydrogen in transport only becoming valuable to the system in largely implausible scenarios’. But it says liquid hydrogen may be viable in aviation, and also, converted to ammonia, in shipping. Indeed it says finding low carbon solutions for these sectors is vital to the net zero strategy, with the marine sector being especially sensitive. There are some signs of progress in this area, but one doesn’t have to be a ‘deep green’ to ask why are we shifting so much stuff around the world? Or for that matter, opening up a wider set of issues not really covered in the report, why are we still wasting so much energy in poorly designed buildings?
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