Energy resilience has come sharply into focus over the past year due to Russia’s invasion of Ukraine and the associated energy crisis. But aside from geopolitical effects, extreme weather poses the greatest threat to maintaining reliable and affordable energy. Laiz Souto (University of Bristol) and Matthew Wright (University of Oxford, Royal Meterological Society) explain what is at stake.
Extreme weather includes high winds, lightning storms, and severe snow. These all pose a threat to the integrity of energy distribution networks, including power lines, substations and generation assets.
Under climate change, there is evidence that these events will increase in severity, frequency, or both. This poses new challenges to energy power system operators. They must be prepared for, and reactive to, more extreme events. In this article, we will use research from the University of Bristol to quantify the risks, and explore how the energy sector can remain resilient to extreme weather.
Why is energy system resilience important?
The term energy system covers “all components related to the production, conversion, delivery, and use of energy”. This includes power stations, substations and the cables that carry electricity to your home or business. Resilience of this system has many definitions, but all agree that it is about reliable and affordable access to energy even under exceptional circumstances. Resilience is closely related to energy security, which is often talked about by politicians and in the media.
Weather incidents are among the main causes of power system outages. This includes winds, lightning strikes, and snow. In extreme cases, disruptions to power grid infrastructure and operations can result in unacceptably long interruptions to power supplies. This has negative effects on economies, through disturbance to business activities, and societies, through loss of power to homes, worldwide. The US Department of Energy estimates that blackouts cost the US economy $150 billion per year.
Ensuring energy system resilience is therefore of great importance.
Increasing risk of failure
Recent blackouts have shown that power and energy systems worldwide are at high risk of failure – or even collapse – when operating in severe weather. They have indicated different problems in power and energy systems resilience that must be addressed to ensure a satisfactory level of electricity service provision before, during, and after extreme weather events.
In the UK in November 2021, Storm Arwen brought strong winds, and heavy rain, snow and ice. This led to the most severe disruption to power supply since 2005, with almost 1 million affected customers. Although over 80% of affected customers had their supply restored within 24 hours, a small but significant proportion remained without electricity for up to 11 days.
The 2022 Eurpoean heatwave caused power system faults across the continent. As temperatures exceeded 40C, conductors sagged and transformers overheated. This left thousands of people without electricity. Overhead line failures also heavily affected rail services across several regions. This was coupled with increased energy demand, as customers turned on their air-conditioning, and decreased supply, as gas power plants operate less efficiently in hot weather, and nuclear power plants struggle to cool down.
These incidents show that improvements in power system resilience must consider impact mitigation across distinct extreme event categories. Infrastructure and operations can be affected in different ways by different events: energy companies must be prepared for these diverse risks.
How does the sector respond?
In the UK, Distribution Network Operators (DNOs) are responsible for responding to faults on the front line. This means fixing infrastructure that has been damaged and restoring power to those cut off as quickly as possible. For each interruption to energy supply, DNOs are required to report to the National Fault and Interruption Reporting Scheme (NAFIRS), providing a large amount of information about the incident for further analysis.
Furthermore, DNOs are legally obliged to maintain minimum resilience levels at all times. These are defined by planning standards e.g., Engineering Recommendation P2/8 – Security of Supply. There are also financial incentives e.g., Interruption Incentive Scheme, Guaranteed Standards of Performance). These incentives are designed to minimise the number and duration of interruptions lasting longer than 3 minutes.
Despite these obligations and incentives, there are no specific requirements for events that result in multiple failures, or the total failure of a network or substation. Moreover, extreme weather events are deemed ‘outside DNOs’ control’ and excluded from their annual performance figures.
Severe weather events are likely to become more common under climate change. Therefore, energy utility companies must be prepared to maintain a satisfactory level of provision, even under extreme weather operating conditions.
What must be improved?
There are several aspects of the way in which the sector deals with extreme weather events that need work.
Firstly, climate change adaptation plans must be produced by all stakeholders in the energy system. This enables long-term resilience planning. These plans should identify the current and future impacts of climate change on their assets and operations. Recognising risks in this way allows management and mitigation actions to be taken. In recent years, these plans have begun to be developed in the UK, complementing existing emergency plans. But energy companies must ensure they are updated regularly, using up-to-date climate models and data.
Secondly, there must be a multi-agency to energy system resilience. DNOs must interact with other critical infrastructure systems and service providers, working with them to ensure that planning and preparation plans are sufficient for climate risks. This includes energy producers, transport operators, and health services. For example, pre-emptively routing and dispatching mobile energy resources means that essential services are not cut off for long periods of time.
Finally, regular health assessments of network components are essential. This enables identification and rectification of faults and weak points in the system. These components can then be upgraded to the most resilient infrastructure. This includes hardening network components to increase their range of operating temperatures, and replacing overhead lines with underground transmission wires.
Ultimately, climate change adaptation and emergency plans must be jointly implemented. This is necessary to ensure responses to extreme weather events are appropriately planned and executed.
Luckily, improving resilience is something that is on the radar of energy companies. But we need to ensure they plan and adapt ahead of time to maintain a reliable energy supply, and take actions now that will ensure resilience in the future.
This article has been written by members of the Royal Meterological Society’s Energy Special Interest Group. We discuss the impact of weather and climate on the energy sector. We are also hosting a virtual Energy, Weather and Climate Forum on 12 October 2023 to bring academics, policymakers and energy professionals together to identify the challenges and gaps in energy, weather and climate. Sign up to our mailing list here to keep up with our work.
This entry was edited on 30 May 2023.