On this page you can meet the ESO’s Executive Team.

Led by the Executive Director, the ESO Executive Team has overall responsibility for the ESO and the delivery of a safe, efficient and reliable electricity network.

Fintan Slye

Fintan Slye, Executive Director

Fintan joined National Grid ESO in 2018. Prior to that he was Chief Executive of the EirGrid Group, the electricity system and market operator in Ireland and Northern Ireland.  He previously also worked for McKinsey (2006-2008) in Ireland and UK and ESB (1994 – 2006) in Ireland, Europe and the US. 

Fintan holds Masters' degrees in engineering and Business Administration along with diplomas in legal studies and European Law.

Kayte oNeil

Kayte O’Neill, Transformation Director

Kayte joined ESO in 2018. Prior to her current role, she served as Head of Markets and previously led the Strategy and Regulation team where she was accountable for delivering the RIIO-2 price control. She has held a wide variety of senior roles across the business, including three years in Boston with National Grid’s US electricity distribution businesses. Kayte holds a first-class degree in Business Economics and is a graduate of the Harvard Business School Program for Leadership Development. She is a Director on the ESO Board and holds Non-Executive Director roles on the Boards of both Jersey Electricity and Regen. 

Craig Dyke

Craig Dyke, Head of National Control

Craig is Head of National Control for the ESO, accountable for the real time operation of Britain’s electricity network. He was previously Head of International Decarbonisation at National Grid Group, promoting decarbonisation of energy sector at a global level. Prior to that, he was Head of Strategy & Regulation at the ESO, responsible for setting the strategic direction of the business along with the policy and regulatory frameworks to deliver consumer value and net zero ambitions. Craig has been with National Grid since March 2000 and has undertaken technical, commercial and strategic leadership roles in both gas and electricity and is a Chartered Engineer in both fuels. 


Julian Leslie, Head of Networks and ESO Chief Engineer

Julian has had almost 30 years’ experience in electricity system operation for National Grid. This included 4 years working in National Grid US developing a new system operator function for a large part of the Mid-West of America. Julian has a degree in Electrical Engineering, is a Chartered Electrical Engineer and a Fellow Member of the Institute of Engineering and Technology.

Gareth Davies

Gareth Davies, Interim Head of Strategy & Regulation

Gareth has worked in the energy industry for 17 years in a range of UK & EU focused commercial, regulatory and policy roles across the sector and supply chain, including upstream, B2B retail and industrial consumption. Since joining National Grid in 2013 Gareth has worked across various UK business units on a range of commercial and regulatory roles. He has a chemistry degree from University of Leeds and lives near Warwick with his family. 

Huma Ali

Huma Ali, Head of HR

Huma joined the ESO in 2015 having previously worked in a variety of HR roles across National Grid Group and its predecessors. She holds a degree in Business Management and is Chartered status with the Institute of Personnel and Development.

Charlie Pate

Charlie Pate, Chief Financial Officer

Charlie is Chief Financial Officer for the ESO, joining us in September 2023 from the Ministry of Defence (MoD). Charlie sat on the Defence Board as CFO where he headed the finance, analysis, and project delivery functions. Prior to that, Charlie held a variety of roles across the UK Civil Service, particularly in HM Treasury. These included leading the development of the public funding package for the 2012 London Olympics, supporting project initiation for Crossrail and overseeing budgets for the criminal justice system. Charlie is a member of the Chartered Institute of Public Finance and Accountancy (CIPFA). 

Jake Rigg Profile

Jake Rigg, Head of Corporate Affairs

Jake is Director of Corporate Affairs at National Grid Electricity System Operator (ESO). Jake joined the ESO from Affinity Water, the water supplier to 3.7 million people in the South-East. At Affinity he led on environmental sustainability and innovation work as Corporate Affairs Director, in particular championing chalk streams. He has also worked on sustainability issues as a consultant to several large companies including investment banks and clearing houses, DuPont, and 3M.

He was an advisor to a former Secretary of State for Energy and Climate Change. He has a degree in modern history from Oxford and is currently completing research on quantifying political and regulatory risk at Yale. He lives in Buckinghamshire with his wife and two daughters.

Zoe Morrisey

Zoe Morrisey, ESO Legal Counsel and Company Secretary

Zoe joined National Grid in 2012 and has worked across the various UK business units advising on a range of regulatory and commercial matters. Prior to joining National Grid Zoe worked for Ofwat and in private practice in the competition and procurement team having qualified to practice as a solicitor in 2008. Zoe has a degree in Law with German as well as two postgraduate diplomas in competition law and economics for competition law.

Claire Dykta

Claire Dykta, Head of Markets

Claire is Head of Markets for the ESO and has over 20 years of experience within National Grid, spanning operations and trading, European and UK code development, regulatory price controls, and strategy and transformation. Prior to her current role, Claire was Head of Corporate and Regulatory Strategy in the UK for National Grid Group. She is a passionate advocate for increasing diversity, equity and inclusion across the energy sector and is also the executive sponsor for the Group’s veterans employee resource group. Claire sits on the Advisory Boards of Oxford University’s UK Centre for Research on Energy Demand and Cambridge Energy Policy Research Group. 


Shubhi Rajnish, ESO Chief Information Officer

Shubhi has over 22 years of experience driving commercial value through Digital and IT strategy, transformation, and delivery. Before joining National Grid ESO, she held senior positions in BAT plc and BP plc. In BAT, she was accountable for Digital and Data transformation for the Corporate Functions and designing the technology strategy to enable future enterprise transition. At BP, she delivered strategy, roadmap, and implementation of digital services across Exploration, Well Operations and Production. She holds a degree in Civil Engineering and an MBA in Change Management. She is a Non-Executive Director, and Board EDI champion for the National Children’s Bureau.