New Future Energy Scenarios

National Grid ESO’s latest round in their Future Energy Scenarios (FES) series sees the UK reaching net zero carbon by 2050, with one scenario (‘Leading the Way’) achieving that by 2047. The UK can also achieve its legally-binding target of slashing greenhouse gas emissions by 78% by 2035. But all this will only be possible if consumers embrace new ways of using energy, and it will require urgent policy decisions to drive immediate energy efficiency measures.

In terms of the energy supply mix, the NG- Energy Systems Operator study says, depending on the scenario ‘between 34 GW and 77 GW of new wind and solar generation could be required to meet demand in 2030.  This could require as much as 13 GW of new electricity storage in 2030 to help balance periods of high and low renewable output.  6 GW of new flexible residential demand reduction is available in Leading the Way by 2030.’ In addition ‘by 2035, at least 2 TWh of hydrogen storage is required in net zero scenarios to provide whole energy system resilience’. 

Hydrogen certainly plays a central role in all of the net zero scenarios, with electrolysis, using surplus wind or solar power, introducing significant flexibility to the electricity network, while hybrid heat pumps and hydrogen boilers replace natural gas in some scenarios. Rather bravely, given that it’s a contentious area, NG-ESO say ‘currently, there is not a huge difference in costs between producing blue hydrogen, green hydrogen and biomass hydrogen (all in a range of 1.2 - 3.3 USD/kg of hydrogen). As technologies are scaled up over time, the differences may increase or decrease, but it is useful to note now that no single process is much cheaper than another’. 

Well that range is actually quite wide, and mostly green hydrogen is still at the top end of the range. Also, there will be differences in net CO2 production- although in that case green hydrogen does best. Even with CCS, it says conversion of natural gas to so-called blue hydrogen will lead to more net emissions than green power-driven electrolysis producing green hydrogen. So it lines up with other studies critical of blue hydrogen, one of which looked at fugitive methane emissions and suggested that, net, up to 20% more emissions might be produced than if using the fossil gas direct.   

Interestingly NG-ESO note that there can also be a big difference in overall energy conversion efficiency. For example, they say that, if zero carbon green hydrogen is converted back into electricity to run a heat pump, the overall energy efficiency is the highest of the options they look at - 92%. That’s because heat pumps can deliver 3 or 4 times more heat than if the electricity was used direct for heating. 

National Grid ESO seem confident that green hydrogen will win out against blue hydrogen on cost, but they do also look a biomass gassification-derived hydrogen and nuclear powered electrolysis-derived hydrogen. However, biomass and nuclear hydrogen only expand significantly in their system transformation scenario, and even then not much. Fossil gas derived blue hydrogen also does better in that scenario, but in their fast expansion ‘leading the way’ scenario, green hydrogen wins out. The end result, in capacity terms, is that nuclear electrolytic H2, only figures slightly in System Transformation and (a bit more) in Consumer Transformation. That may be why nuclear grows to 15 & 17 GW respectively, otherwise it falls to less than now, with maybe a few SMRs to partly replace old reactors.  

Heat and road transport reach zero, or almost zero, emissions by 2050 across all scenarios, except the slow path ‘Steady Progression’. But in all cases, carbon removal is needed to offset emissions in aviation. The NG-ESO study says ‘Bioenergy with Carbon Capture and Storage (BECCS) is the largest provider of negative emissions in all scenarios that reach net zero, but nature-based solutions like afforestation, reforestation and peat restoration all feature heavily with Direct Air Carbon Capture and Storage (DACCS) also playing a role in Leading the Way.’  

That raises some big issues - can national CCS be expanded on the scale needed? Will there be enough room for all the biomass growing envisaged, including for carbon negative BECCS, or will some have to be imported?  Another set of issues concerns heating. While they do back heat pumps, NG-ESO also see a role for heat storage at the domestic level to support flexibility, in conjunction with hydrogen use - they envisage there being 5GW of green hydrogen capacity by 2030 in the Leading the Way scenario. They say heat pumps are greatly influenced by the availability of alternative technologies and by location. Based on their new area-by-area study they say ‘if there is no cost-effective alternative, for example in Scotland in Consumer Transformation, heat pumps fill the gap. Hydrogen boiler deployment depends on the availability of hydrogen. For example, the national hydrogen transmission system in System Transformation provides the opportunity for more homes to install hydrogen boilers. In this scenario, south Wales has high concentrations of hydrogen boilers, in part due to its high housing density and fewer alternatives compared to other areas’.

There is no doubting that all these scenarios imply a lot of changes in how we use energy. NG ESO note that ‘even Steady Progression (our slowest decarbonising scenario) sees 4.7 m EVs and 1.9 m heat pumps connected by 2030’. We can quibble about some of the details, but the general trend seems clear- renewables are going the expand very rapidly and that will open up a lot of issues. So will meeting demand for some of the services that we take for granted- aviation in particular. NG ESO think biofuels can help, but that we will also need carbon offsets. I’m not sure that’s a wise way to go- putting ourselves in carbon hock just to fly.  And in terms of managing demand peaks for electric vehicle charging, I’m not convinced NG ESO’s optimism is well placed: ‘We expect high take-up of smart charging in households with off street parking and their own home chargers. Government and industry impetus suggest this is likely to be widespread. Smart meters, time of use tariffs and automation will make the experience simple for the consumer. We expect smart charging to keep additional peak electricity demand from electric vehicles to between 7 and 16 GW, lower in the scenarios with high levels of consumer engagement’.  More practically, they say ‘during the daytime we expect some commuters to plug in their cars at work’. Well yes, but that assumes people will still be going to work (or anywhere) by car!