Flexibility in Great Britain


A Net Zero energy system

Groundbreaking analysis of the system-level value of deploying flexibility across the heat, transport, industry and power sectors in Great Britain has been published in the Flexibility in Great Britain report. Its findings are expected to have profound implications for policymakers, households and the wider energy sector.

Why do we need flexibility?

Reaching net zero by 2050 will require an unprecedented expansion of the country’s energy system. Flexibility in the energy system is crucial to help meet this demand cost-effectively and realise numerous other benefits. It is vital to act now on flexibility.

Flexibility is vital to unlock value and it is the most important ‘no regrets’ action that can be taken as the UK moves to decarbonise heat, transport and industry, saving billions in investment and operating cost.

Tom Delay, Chief Executive, the Carbon Trust

The analysis

Three scenarios were considered:

Electric heating

Hydrogen heating

Hybrid heating electric with back-up gas boiler

Each scenario has a significant impact on the shape and form of the future energy system, but whatever the heating scenario, flexibility delivers.

Key findings

Cutting the cost of net zero

A fully flexible energy system has the potential to deliver material net savings of between £9.6 billion and £16.7 billion per annum in 2050.

Savings calculated across all three scenarios:

A more resilient system

Flexibility will enable the development of a safe and secure net zero energy system that can operate cost-effectively in diverse situations such as dark, cold and windless days in winter or hot summers.

Demand side response and thermal storage reduce electricity demand peaks, while battery storage and interconnectors help to meet remaining demand, reducing requirements for back-up generation.

Hourly electricity demand (GW) during a 1-in-20 year cold snap coupled with low renewable output (Wednesday - Friday), under low and high flexibility scenarios.

It’s time to act

Flexibility should be integrated into enabling infrastructure including low carbon heat and transport solutions from the start.

The scenarios show the amount of different types of flexibility we will need in 2050. We have estimated how much flexibility we need to deploy in the next decade to remain on track for a flexible 2050 system, and identified the barriers which will need to be overcome. Investment in flexibility is needed now to set Great Britain on the path to a flexibility, cost-effective, net zero energy system.

This chart shows the indicative deployment trajectory of flexibility from EVs across the three core scenarios.

Local and national value

Distributed flexibility assets deliver significant value locally, but even more value is realised when coordinated at a national level.

For example, investing in additional flexibility within Greater London delivers:


savings to London directly in reduced distribution network costs

+ £900m/yr

additional wider system savings

The role of hydrogen

Coordinating hydrogen production capacity and associated infrastructure effectively has significant system benefits. There is a need to diversify hydrogen production routes and develop CCS infrastructure at scale to deliver hydrogen cost effectively.

If hydrogen is used to meet a significant proportion of heating demand through electrolysis alone, the system cost is significantly higher. A mixture of production routes is lowest cost across all scenarios examined.

Public support is vital

To maximise the benefits of flexibility, households and businesses will need to play an active role in the development and operation of the country’s future energy system.

Consumer engagement and confidence building is critical to scaling up the provision of demand side flexibility, through the operation of their smart appliances, electric vehicle charging and home heating systems, for example.

For flexibility to be rolled out successfully, it is crucial to develop business models which capture its value and to overcome consumer acceptance challenges when delivering new mobility, heating and smart appliance solutions.

Insights for industry and government

  • It is vital that existing flexibility options are preserved and action is taken now to maximise future flexibility
  • A whole system approach means that policies – across transport, heat, power - can’t be made in isolation
  • Flexibility should be treated as a core infrastructure challenge and be integrated into low carbon generation, network planning and heat and transport decarbonisation strategies
  • Regulation must incentivise investment in flexibility
The report demonstrates that energy flexibility can reduce the cost of meeting net zero and mitigate the impact of wider changes in the energy system, ensuring we reach net zero efficiently, effectively and at lowest cost.

Baroness Brown of Cambridge, Chair of the Carbon Trust

Project delivery team

The analysis was led by the Carbon Trust and independent researchers from Imperial College London.

Our partners

The analysis was supported by a cross-sector group comprising: Bryt Energy, EDF, Greater London Authority, IGEM, Kiwi Power, Low Carbon Contracts Company, SBM Offshore, SP Energy Networks, Statera Energy, Scottish and Southern Electricity Networks, UK Power Networks and Western Power Distribution.

An external stakeholder group was also consulted comprising: BEIS, the Climate Change Committee, Innovate UK, National Grid ESO, National Infrastructure Commission and Ofgem.

Find out more in the Flexibility in Great Britain report

How can we help you?

We welcome engagement on the report and its findings. Contact us to speak to the report authors and our energy systems team.

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