Consumers require energy that is clean, secure, affordable, and fair. This is achievable but relies on urgent and strategic development of networks, markets, and technologies. This chapter takes a closer look at how the energy system will need to continue to evolve.

Key insights from the Energy System

We have already seen the GB energy system evolving as new technologies and innovations emerge, and the electricity system in particular has decarbonised rapidly. To reach Net Zero by 2050, the energy system will need to continue to evolve, while maintaining Security of Supply.

  • Achieving Net Zero by 2050 across the whole economy will require Greenhouse Gas Removal in some sectors to offset emissions from hard to abate sectors. The energy sector is well placed to deliver this through technologies such as Bioenergy Carbon Capture and Storage (BECCS) and Direct Air Carbon Capture and Storage.
  • Decarbonising sectors like transport, and potentially heat, will require significant electrification and electricity ultimately overtakes fossil fuels in all scenarios to become the biggest supplier of energy to end users. This means the power sector must first be fully decarbonised.
  • Driven by the need to ensure this electricity is carbon free, affordable, and sustainable, renewables emerge as the dominant source of electricity generation for Britain between now and 2050. By 2030, wind and solar generation will have risen to at least 66% in Falling Short (from 43% today) and by 2050, it will meet 70% and 84% of annual electricity demand.
  • A range of flexible technology is needed to integrate this generation output from weather dependent renewables, ensure supply is reliable and minimise curtailment. Our scenarios demonstrate the importance of utilising low carbon technologies and fuels, especially hydrogen and Carbon Capture Usage and Storage, alongside electricity storage, interconnection, and demand side flexibility, to deliver a balanced whole energy system.
  • Across all scenarios, strategic investment is required now to develop this whole energy system and deliver clean, secure, affordable, and fair energy for all consumers.

Bioenergy has an important role today and one that changes in the future. Most of the required emissions reduction across the economy between now and 2050 comes from reducing demand and replacing fossil fuels with renewables or low carbon alternatives. However, negative emissions from Bioenergy with Carbon Capture and Storage (BECCS) and other Greenhouse Gas Removal methods are still required to offset emissions from sectors of the economy which are ‘hard to abate’. Reaching Net Zero by 2050 without BECCS would either require higher levels of lifestyle change (e.g., changes in diet or travel patterns) or improvements in other Greenhouse Gas Removal technologies to an extent that we consider challenging at this time.

  • In 2050, BECCS for power generation accounts for between 50% and 66% of total bioresource demand in our Net Zero scenarios and provides between 24% and 66% (21 and 58 MtCO2e in Leading the Way and System Transformation respectively) of the negative emissions required to offset ‘hard to abate’ sectors. Sustainability and carbon accounting must be considered when deploying BECCS.
  • In System Transformation and Consumer Transformation, around 43% of the demand for bioenergy is met by imports in 2050, but in Leading the Way, only 3% of bioenergy is imported in the form of biofuel with all other feedstock, including biomass, being sourced in Britain by 2050. Sustainability criteria will be easier to assess for domestic supply chains and reduced reliance on imports also strengthens energy security.
  • Bioenergy plays a key role from a whole energy system perspective as it is used for BECCS in the power sector, for biomethane on the natural gas system and to produce hydrogen via biomass gasification. This is in addition to limited direct use in heating and transport.
  • In Leading the Way, we assume a minimal amount of BECCS in order to offset emissions across the economy - and that all biomass feedstocks will be sourced domestically. More is applied in the other Net Zero scenarios with a greater contribution from imports. This is to reflect varied stakeholder feedback on the role of bioenergy in meeting Net Zero as well as uncertainty around policy post-2027[1]. FES modelling is done on the basis that all bioenergy feedstock meets the Government’s criteria for sustainability.

The design of the energy system we have in Great Britain today has been shaped by the previous dominant sources of energy (coal, and then later natural gas) – from the way we provide heat for homes and industry, all the way to generation of electricity. Today, gas still meets around 40% of total UK energy demand, and the renewable integration achieved to date has been successful in part because of the ability of the gas generation fleet to flex its output to wind and solar levels. However, transitioning towards Net Zero while maintaining a reliable and affordable energy system for all will require a continued, if different, role for natural gas as it cannot be used in a Net Zero world without its emissions being captured.

  • Our analysis shows that there is sufficient gas supply between now and 2050 to ensure Security of Supply. This is partly due to the diverse sources of natural gas available to GB, and also because we expect natural gas demand to decline through energy efficiency improvements and increased renewable generation. However, as long as gas is in demand for heat and power, we will be exposed to price fluctuations in the global energy market.
  • In 2021 63% (50 bcm / 550 TWh) of Britain’s gas was imported. By 2050, import levels could be as high as 98% of total supply in System Transformation though falling gas demand means the actual amount of imported gas would be less at 35 bcm (385 TWh).
  • The level of natural gas in 2050 is mostly influenced by the future of residential heat and hydrogen production. In Falling Short, annual natural gas demand remains at 65% of today’s level as it is still widely used for residential heat whereas in Consumer Transformation, our most electrified scenario, this drops to just over 3%. How hydrogen is produced also makes a significant difference with System Transformation requiring over 5 times as much natural gas than Leading the Way due its far greater reliance on methane reformation compared to electrolysis.
  • Gas and hydrogen infrastructure: The gas network is still being used in 2050 in System Transformation and Falling Short, albeit with modifications to transport hydrogen in the former. In Leading the Way, the network required is not as extensive and, in Consumer Transformation, it is much reduced by 2050 due to reduced demand and lower levels of hydrogen.
  • In all net-zero scenarios, levels of unabated gas for power generation reduce significantly with residual gas generation capacity remaining on-line to ensure Security of Supply. In Leading the Way, no such capacity remains on the system after 2035.

Hydrogen is an emerging technology that plays a key role in all our Net Zero scenarios. In addition to being able to replace most uses of natural gas in the energy mix, its production via electrolysis and ability to be stored over long time periods can help to overcome the challenges, and harness the opportunities, that come with increased renewable generation in the electricity system – even in Consumer Transformation.  However, despite being an essential part of the future energy system, its credible range in terms of both how much energy demand it meets and how it is produced is very wide. Clarity is needed as soon as possible on the future role of hydrogen, especially in residential heating as this will support the strategic coordination and whole energy system thinking required to meet Net Zero in a way that is secure, clean, affordable and fair.

  • The credible range of possible hydrogen use is very wide and this impacts the development of hydrogen infrastructure. While hydrogen for power generation is needed in all our Net Zero scenarios to support electricity Security of Supply, the broader levels of demand, hydrogen production methods, and end uses vary greatly between the scenarios.
  • A clear understanding of the desired benefits hydrogen is expected to provide, as well as how costs vary for different use cases, is vital. Relatively small changes in annual load factor, electricity price or commodity (natural gas and hydrogen) price can drastically affect the commercial viability of a hydrogen value chain and so the role of markets to provide clear signals is paramount.
  • Leading the Way meets the target of 10 GW of hydrogen production by 2030 set out in the British Energy Security Strategy. However, a corresponding demand side strategy is required to ensure that the hydrogen produced is effectively used and that the level of blending into the gas system is minimised.
  • Hydrogen supports operation of the energy system of the future as the production of hydrogen via electrolysis helps to integrate renewable electricity generation and reduce curtailment. This is because surplus electricity can be used to produce hydrogen at times of network congestion. High levels of electrolysis in Leading the Way contribute to it seeing the lowest levels of curtailed energy.
  • To fully realise the whole system benefits of hydrogen, and to provide energy security without unabated gas, high levels of hydrogen storage will be required. This is the case across all the Net Zero scenarios and, given the likely geological aspect of these projects, strategic investment is required now.
  • Biomass gasification can be combined with Carbon Capture Usage and Storage to make carbon emissions from hydrogen production net negative in Leading the Way and System Transformation. This offsets residual emissions in other sectors.

Decarbonisation of GB’s whole energy system, and reducing the country’s exposure to global energy markets, cannot be done without investing in our electricity system and our ability to accurately match demand to a weather-dependent supply. We have seen significant progress in the proportion of electricity from low carbon and renewable generation in recent years and this has spearheaded the wider emission reductions across the economy. Low carbon generation now accounts for 78% of annual domestic electricity supply compared to less than 30% ten years ago, and there is further potential that can be unlocked.  A range of technologies with different characteristics can, in combination, help deliver secure, affordable low carbon electricity supplies and harness the potential of domestic renewable resources.

  • Decarbonising electricity supply is a prerequisite for decarbonisation of other sectors like transport and heat by electrification. Load factors of gas-fired generation reduce significantly in all Net Zero scenarios and, in Leading the Way, there is no unabated natural gas capacity after 2035.
  • The emergence of Bioenergy with Carbon Capture and Storage for power generation allows the electricity system to achieve net negative emissions in 2033 in Consumer Transformation and Leading the Way and in System Transformation in 2034.
  • Wind and solar made up 43% of domestic electricity generated in 2021 and, by 2030, they dominate accounting for 66% even in Falling Short. These levels of renewable output require the corresponding generation capacity to be much larger than previously due to the relatively lower load factor of wind and solar. This means the system evolves from one where supply responds to meet demand, to one where supply and demand need to flex to balance the energy system.
  • Energy markets will need to be reformed to ensure the flexibility needed to integrate renewable generation efficiently is unlocked. Different flexible technologies will fulfil different roles with particular focus being required for those requiring the longest lead times (geological storage) and dependencies on other sectors (e.g., hydrogen and Carbon Capture Usage and Storage generation).
  • High levels of renewable capacity combined with low flexibility baseload generation results in material levels of curtailed energy from around 2030. This is purely due to energy imbalances (i.e. rather than network constraints). The lower levels of curtailment in Leading the Way compared to the other scenarios highlights the whole system benefits of electrolysers producing hydrogen at times of oversupply.
  • Integrating large volumes of renewables, especially offshore wind, will require strategic whole system planning and coordination, as well as anticipatory investment, to avoid exacerbating existing network constraints. Regional coordination between distribution and transmission networks, transparent locational price signals, optimised offshore solutions, and consideration of hydrogen and electricity imports and exports will all be required to provide the most secure, affordable and fair outcome for all consumers.