Fintan Slye: Reflects on the first year of the National Energy System Operator

A year ago today, on 1 October 2025, with support from government, industry and customers, the National Energy System Operator (NESO) was born. This brand-new public corporation was now not just responsible for operating the day-to-day flow of electricity around our isle, but much more. With this key milestone reached, I wanted to take this opportunity to share some of my reflections of our first year, including some of  the successes and challenges along the way.

It is a privilege to sit at the heart of Great Britain’s energy system, and I am proud of what we have been able to deliver in our first year, branching out from our traditional role.

Even before NESO’s founding, and within days of the new Government coming into power, we were asked to prepare analysis and deliver advice to government on how to deliver clean power by 2030 – our first big project of providing robust analysis which was credible, expert and independent. It was a huge amount of work to deliver in such a short timeframe, and that is testament to the deep, impressive expertise of colleagues across NESO, spanning the knowledge base of the energy sector to bring holistic insights together.

In the last year NESO has been, and is currently tasked with, delivering connections reform. This is a hugely complex but transformative programme of work for both the energy sector and Great Britain’s economy, unlocking more than £40bn worth of investment.

These reforms have been years in the making, with collaboration across industry, government and the regulator to deliver this once-in-a-generation change. We are the first to acknowledge there have been challenges, and we are grateful for the support and feedback from industry and customers. There is much more to do, and we look forward to working with industry, the regulator and government on this, making sure these reforms deliver the very best results across Great Britain.

As part of the new powers bestowed on NESO through the Energy Act, we were commissioned in March of this year to conduct our first independent investigation into the power outage at North Hyde substation. This is a responsibility we took incredibly seriously given the impact of the incident on hundreds of thousands of people. This work wasn’t easy, especially as we were navigating how to use our new powers for the first time on such a high-profile event. Despite this, we delivered an expert and comprehensive report which will hopefully drive positive change to improve the resilience of all our Critical National Infrastructure.

These three things alone – our clean power advice, connections reform and our review into the North Hyde incident – demonstrate the breadth and value of NESO just one year into our existence. And that is not to mention the core of the work that we continue to do operating the electricity system second by second.

What is clear to me is the cross-sector collaboration that led to our creation will be essential for our success as we navigate the energy transition in Great Britain to serve the needs of our economy and our society.

Fintan Slye
Chief Executive
NESO