Energy Grid Resilience

Statement

The following Statement was made in the House of Commons on Wednesday 30 April.

“With permission, Mr Speaker, I will make a Statement on the resilience of the UK’s energy grid in the context of the widespread power outages experienced across the Iberian peninsula over the past two days. My thoughts are with all those affected by the widespread disruption across that peninsula on Monday. I am glad to hear that power has now been fully restored across the region.

I want to reassure the House that Great Britain has a highly resilient energy network, and that the incident in Iberia has not impacted Great Britain. The Secretary of State has been in regular contact with the National Energy System Operator over the past two days, and it has provided reassurance that there is no increase in risk to our energy supplies or system stability from this incident.

My department was informed on Monday 28 April by NESO that a power outage had occurred across the Iberian peninsula, affecting mainland Spain, Portugal, Andorra and areas of France. While all power was restored to the impacted areas yesterday, Tuesday 29 April, the disruption had cascading impacts on other sectors across the vast majority of Spain and Portugal. The cause of the outage is yet to be confirmed; it is likely to take some time for the Spanish network operator to carry out a thorough investigation to determine the exact cause of the failure. Various independent reviews have been commissioned by Spain, Portugal and the European Commission to understand the cause.

Although GB is not directly connected to Spain and Portugal’s grid, NESO is in close contact with European counterparts and is offering support where needed. The Government are closely monitoring the situation and are in contact with the Spanish and Portuguese authorities to ensure the safety and well-being of any British nationals in the affected regions.

I turn to our grid’s resilience, and our preparedness in the context of recent events on the Iberian peninsula. An event similar in impact in Great Britain would be equivalent to a national power outage—a total loss of power across the whole of GB—which is listed on the national risk register as a high-impact but low-likelihood event. In its 75-year history, Great Britain’s national electricity transmission system has never experienced a complete shutdown, or anything on the scale of what has happened in Spain over the past few days.

Our electricity system is highly resilient. The National Energy System Operator continuously monitors the condition of the electricity system to ensure there are sufficient inertia and reserves in the system to manage large losses and prevent large-scale power outages. NESO has also introduced innovative new approaches to managing system stability, as well as advanced safety systems to help to prevent such events from happening in GB. The system is built, designed and operated to cope with the loss of key circuits or systems without causing customer impacts. There are multiple redundant alternative routes through which power can flow should a fault occur, minimising the risk of a single fault cascading across the entire system to cause a total or partial electricity system shutdown.

However, as a responsible Government, we prepare for all eventualities, no matter how unlikely. I would like to reassure the House that the Government work closely with industry to continually improve and maintain the resilience of energy infrastructure, networks and assets to reduce vulnerabilities. This work includes having robust emergency plans, summarised in the national emergency plan for downstream gas and electricity, and regularly exercising emergency plans with the energy industry and Ofgem. That includes an exercise carried out by the previous Government; we have been taking forward the recommendations from that exercise. This work is ongoing across government to ensure we are as resilient as possible as a nation in all eventualities.

We have also empowered the independent National Energy System Operator to carry out resilience functions across the electricity and gas systems, and will continue to work with industry and regulators to improve and maintain the resilience of old, new and future energy infrastructure. Switching fossil-fuelled generation for home-grown clean energy from renewables, nuclear and other clean technologies is the route to long-term energy security. I will speak more broadly about the UK’s energy resilience in a debate in Westminster Hall on Tuesday.

To conclude, Great Britain has a resilient energy network, and we will ensure that that continues to be the case. I commend this Statement to the House”.

My Lords, I begin by expressing my sympathy for all those impacted by the recent blackouts in Spain, Portugal and beyond. This blackout should serve as a stark reminder of the consequences when the power grid fails. Prolonged blackouts are devastating. The collapse of the grid in Iberia highlights the vulnerability of our complex, interconnected systems that underpin modern life, as well as the profound human impact that such failures can have. We must ensure that this does not happen in Great Britain, as the economic and social consequences would be catastrophic.

The Government’s plan to rapidly build a grid that is dependent on naturally unreliable and intermittent renewables in just five years will severely compromise the reliability of our electricity supply. The stability of a grid depends on what physicians know well as inertia—the ability to resist destabilising fluctuations in frequency. This has been a key factor in the security and resilience of our grid over the years. Inertia is provided by turbines in nuclear, hydro and gas power stations, but it is not provided by solar and wind farms. Without sufficient inertia to buffer against sudden frequency shifts, the grid risks destabilisation, potentially triggering a domino effect of system failures that culminates in widespread blackouts.

The most recent annual report from Spain’s equivalent of NESO highlights the risk of relying too heavily on renewables. It concluded that the closure of conventional power plants such as coal, gas and nuclear has diminished the grid’s balancing abilities and inertia. What is deeply concerning is that the same trend is occurring here in the UK. Data from NESO has shown a steady decrease in grid inertia as gas and coal plants are replaced by wind and solar. The transition carries a significant cost, which exemplifies the flaws in much of this Government’s accelerated energy security strategy.

My Lords, I thank the Minister for the Statement on the power outages across the Iberian peninsula. Our thoughts are of course with the 55 million people across Spain, Portugal, Andorra and parts of France who were affected.

The Statement rightly highlights the highly resilient nature of Great Britain’s energy. I welcome that we will continue to improve our resilience and ensure that our energy systems are robust and that we have the proper exercises in place. We note that a similar event in Great Britain—a total loss of power—is listed on the national risk register as high impact but very low likelihood. It is reassuring to hear that the Minister has been in regular contact with the National Energy System Operator and is working closely with industry to maintain the resilience of our energy infrastructure.

I also welcome the Government’s taking forward recommendations from previous exercises such as Mighty Oak. As the Minister has noted, the exact reasons behind the power failure remain uncertain. We note that independent examinations are going on and that the Spanish and Portuguese Governments and the European Commission are all examining the causes.

The truth is that there are probably several interlinked events that caused this power outage. Sadly, despite the fact that the causes are at the moment unknown, a “firestorm of disinformation” has already erupted, with some attempting immediately to blame the use of renewable energy. We echo the Spanish Prime Minister’s call for caution against misinformation and disinformation. Energy experts have been quite quick to dismiss renewables as the primary cause.

On disinformation, Carbon Brief notes that UK newspapers have already launched more incorrect editorials attacking our net-zero policies in the first four months of 2025 than they did during the whole of 2024. So I take this opportunity to ask the Minister, what actions are the Government taking to improve government communications and actively counter disinformation in this area?

My Lords, I thank both noble Lords for their comments, and I join them in expressing my sympathies for those affected. I am glad to hear that power has been fully restored across the region.

As noble Lords have suggested, the Spanish Government are undertaking a review. We do not yet know the outcome, and I suggest that it is best to await the review before we can look properly at any potential lesson or impact on our own system. Clearly, it is entirely understandable that noble Lords should raise the question of the resilience of our own grid. The Secretary of State has been in regular contact over the past week with the National Energy System Operator, which has provided reassurance that there is no increase in risk to our energy supplies from that incident.

The intervention of the noble Lord, Lord Offord, did not come as a surprise to me. We still believe that the best way to secure energy independence is through clean power. The Office for Budget Responsibility has assessed that responding to future gas price shocks could be twice as expensive as the direct public investment needed to reach net zero.

I hope I can provide some reassurance on the issue of inertia. NESO continuously monitors the condition of the electricity system to ensure that there are sufficient inertia reserves to manage large losses. System inertia is the kinetic energy stored in the spinning parts of the generator connected to the electricity system. If there is a sudden change in system frequency, these parts will carry on spinning and slow down that change. System inertia behaves a bit like shock absorbers in a car’s suspension, which dampen the effect of a sudden bump in the road and keep the car stable and moving forward.

In the context of renewable energies, NESO has introduced new technologies such as flywheels to increase inertia and establish new commercial mechanisms to procure these on the GP system as more non-synchronous generation is built and makes up a large proportion of the energy mix. It has also introduced innovative new approaches to manage system stability and the system is designed, built and operated in a way that can cope with the loss of key circuits or systems, minimising the risk of significant customer impact.

My Lords, does the Minister accept that an essential tool in balancing UK electricity network capacity is the availability of a significant additional number of pumped storage hydro schemes? Will he urge GB Energy to accelerate the pumped storage projects currently under consideration and reconfigure grid capacity to facilitate this?

My Lords, the noble Lord makes an important point. I certainly accept that pumped storage energy has a role to play. I shall make sure that Great British Energy is apprised of the views he has taken. He knows that we wish them to operate independently within the strategic framework, which we have debated extensively, but it is a very apposite point, which I will pass on to the chair.

My Lords, as was recognised in the other place, reports suggest that Programme Yarrow and Exercise Mighty Oak yielded useful insights and made a valuable contribution to our preparedness in the event of a disruption to the UK’s power supply. However, as proven by the previous Government’s failure to act on the findings of Operation Alice, resulting in a lack of planning for track and trace, border security and lockdowns consequent on the arrival of a pandemic, such diagnostic exercises are only as useful as subsequent actions taken to recommend identified shortfalls in resilience. With this precedent in mind, is my noble friend able to reassure your Lordships’ House that the findings of Programme Yarrow and Exercise Mighty Oak are under constant review and, importantly, that we continue to account for advances in capabilities among those strategic adversaries who might seek to target our critical energy infrastructure?

My Lords, Mighty Oak was a successful programme to test plans for full electricity restoration in the event of a national power outage. It was very successful and generated a number of learning points, and we now have a strong governance framework for oversight of the implementation of those recommendations. That work will also feed into the resilience review that my right honourable friend the Chancellor of the Duchy of Lancaster announced in July 2024.

I assure my noble friend that there is absolutely no complacency whatever, and nor is there any in relation to the energy security system and cybersecurity threats he referred to. It is certainly a key priority for the Government. We work closely with the National Protective Security Authority and the National Cyber Security Centre and we are certainly not complacent on this.