CXC researchers Marcel Nedd and Keith Bell, University of Strathclyde, discuss the findings of their recent report on security of electricity supply.

 Just a few months ago, Storm Arwen caused widespread damage across the UK. In Scotland, following damage to the network, more than 100,000 homes were left without electricity, as were hundreds of businesses and transport operators. For some, it took more than a week for power to be restored. Arwen was billed as ‘one of the worst storms in a generation’[1]. Yet, it was followed, within weeks, by Storms Malik and Corrie – and further, widespread power outages.

 Coping with the impact of more frequent extreme weather events is one of several challenges facing the UK’s electricity supply landscape. Over recent decades, the system has adapted to accommodate a vast increase in energy from renewables and a corresponding decrease in large, fossil-fuelled power stations. Scotland has also seen a reduction in production of energy from nuclear power with the recent closure of Hunterston[2]. As well as changes to the sources of energy, the technologies on the system are changing with less use of the sorts of large electrical machines that have been the mainstay for many decades and more use of energy sources connected via power electronic interfaces. This potentially radically alters the dynamics of the system. While all these changes are happening, security of supply still needs to be ensured – being able to access enough dependable sources of electricity to meet the demand for power sufficiently often, and to prevent, contain and recover from any power supply interruptions.

 Our new report  draws on a survey and workshop conducted with industry experts and key stakeholders to build a picture of Scotland’s security of electricity supply today and in the future. It focuses on five aspects linked to security of supply and two others that relate to greenhouse gas emission-reduction targets and offshore wind ambitions. The research identifies some significant challenges while also highlighting steps that can help ensure security of supply as the energy transition continues and the use of variable renewables such as wind and solar power increases.

While expressing strong support for reducing greenhouse gas emissions to net zero, stakeholders raised concerns about how achievable Scotland’s 2030 and 2045 emissions reduction targets are. Many were also not confident Scotland would meet its offshore wind generation capacity ambition by 2030 – although the consultation was carried out before the results of the Scotwind offshore leasing round were announced.

Participants in the research highlighted that it will become more challenging for the electricity system in Scotland to provide a secure and stable supply over the period to 2030 – in particular when faced with periods of ‘wind drought’ when there is little power from wind farms and in ensuring sufficient resilience against disturbances. At the same time, noting Scotland’s place as part of a GB-wide electricity market and network interconnections with other countries, these industry experts and stakeholders expressed confidence in the system’s ability to meet Scottish electricity demand going forward. However, this is dependent on market frameworks and regulatory arrangements keeping pace with changes to the sources of electricity and the technologies.

Key stakeholders proposed a number of actions to help address the challenges identified. These proposals are aimed at both the UK and Scottish Governments as well as electricity network companies, the regulator – Ofgem – and the electricity supply industry as a whole. They include the need to:

  • develop a vision for managing a complex electricity system that reconciles various approaches to managing demand alongside consumer protection;
  • address market barriers and revise sector regulatory standards to ensure that services from generators, flexible demand and energy storage facilities to support stable operation of the system can be efficiently and effectively delivered and coordinated;
  • speed up deployment of engineering solutions to the changing characteristics of the system;
  • ensure that the new standard governing speed of restoration in the event of a national blackout is fully complied with;
  • explore how local electricity systems and the concept of ‘resilience as a service’ (whereby market-based solutions can help maintain supplies in the event of loss of power from the main network) can contribute to security of supply;
  • consider the costs and benefits of a regional capacity market or a similar mechanism aimed at ensuring security of supply in every region of the network, incentivising strategic development of schedulable sources of power at key locations;
  • consider the costs and benefits of facilitating new pumped storage hydropower projects and their potential long-term value to the system.

As the recent storms underlined, power outages are highly disruptive for individuals, communities and business. The research revealed strong support for decarbonisation of the electricity system. However, given the many challenges and changes facing the energy sector there is a need to plan ahead and to adapt to ensure security of supply.

At the time of the work, Marcel Nedd was with the Dept. of Electronic and Electrical Engineering at the University of Strathclyde. He is now with SP Energy Networks.

Keith Bell is with the Dept. of Electronic and Electrical Engineering at the University of Strathclyde.

[1] SSEN, ‘SSEN restores power to homes affected by storm Arwen’, 2021. (accessed Dec. 20, 2021)

[2] (accessed 07/02/2022)