ENSEK founder Jon Slade exits as CEO, Grace Rothery named interim

A founder-led era ends in Nottingham

Jon Slade is stepping down as chief executive of ENSEK, the Nottingham energy-retail software company he helped build over almost 17 years.1 He announced the move in a LinkedIn post, and Grace Rothery takes over as interim CEO.1 Slade said he will stay on as an adviser for a short period, then take a break and probably start another venture.13

In his post, Slade said ENSEK started in 2010 with the aim of solving one of the hardest problems in energy retail. He said the company now ranks among a small number of mission-critical platforms worldwide that can support the energy transition at scale.3 He also admitted that this was not the plan on day one and called the journey a lesson in agility and resilience.3 He credited co-founders Arran Stevenson and James Kirk and the wider leadership team.3 He described Rothery as a strong leader and said ENSEK is in good hands.5

The announcement included no external search, no permanent successor and no detailed statement from the board. Calling the appointment "interim" matters. It suggests the decision on who runs ENSEK long term is still open, and that decision is likely to sit with the company's owner rather than with the founders.

Who is Grace Rothery?

Rothery is an insider who knows the energy-retail market. ENSEK hired her in November 2021 as UK managing director.16 The company's own material says she came from Gazprom Energy, where she was head of UK retail, and that she has held several senior roles at ENSEK, most recently chief of staff.12

That background points to a choice for stability over a reset. A chief of staff usually works across the whole executive team, sees the operating detail of every function and handles the CEO's priorities day to day. Moving that person into the top job keeps continuity at a sensitive time. Her earlier role as UK managing director also means she knows ENSEK's home market well. The company counts that market as its anchor even as it builds offices in Belgium and Australia.2

This is a reasonable choice for a business in the middle of a transformation. It also leaves open whether Rothery becomes the permanent CEO or keeps the seat warm while the owner looks for someone else. Nothing reported so far settles that.

The Centrica factor

The change only makes sense against ENSEK's ownership. Market-intelligence data lists ENSEK as acquired by Centrica, with the deal dated 1 August 2024.7 Coverage of that deal described it as an exit for private equity backer LDC.7 Soon afterwards, ENSEK, now owned by Centrica, bought the customer platform formerly used by Bulb, a deal linked to Zoa Technologies. That took its headcount to about 550 at the time.7

Founders often leave within a few years of a strategic sale. The integration work is mostly done, the earn-out or lock-in periods run out, and the job of running a subsidiary is different from building a company. Slade's exit, about two years after the Centrica deal, fits that pattern. Nothing in the coverage says the timing is linked to any contractual milestone, so this is a reading of the situation, not a reported fact.

Centrica's influence also shows in the recent senior hiring. Oliver Blackwood, ENSEK's chief technology officer since January 2026, came from Centrica, where he was vice-president of engineering. He had earlier held senior engineering roles at Kaluza and OVO.13 Sharon Doyle, who became chief product officer the same month, said the Centrica partnership gives ENSEK strategic backing and distribution. She said the Zoa acquisition adds proven consumer-engagement technology.18 Put together, these show a business run increasingly as a growth platform inside a larger energy group, not as a founder-led independent company.

A rebuilt executive bench

The leadership team Rothery inherits is largely new. Besides Blackwood and Doyle, ENSEK appointed Sharon Robson as chief marketing officer in July 2025.12 Simon Orosz joined as chief revenue officer and brings more than 25 years of experience growing software businesses internationally, including at ClickSoftware, Oracle and Velotix.4 Recent directory listings also show a chief operating officer, a chief financial officer and a chief people officer.16

The new executives have described this period as a turning point. Blackwood said ENSEK is moving from serving one market to expanding internationally and across the energy sector. He called it a reboot of the organisation for growth.13 He also said the company had built its billing platform and proved it with a major UK customer, which he described as a large Tier 1 supplier.13 Doyle described the goal as moving from a billing and metering platform to a full-stack enabler of the energy transition.18

In practice, much of the new strategy was shaped under Slade but will be carried out without him. Doyle said in January that meeting Slade and his team was part of why she joined.18 Founder departures often unsettle recent senior hires. The fact that the interim CEO already sits at the centre of the executive team should limit that risk.

Where the records disagree

The coverage agrees on the main facts: who is leaving, who is stepping in and roughly how long Slade led the company.135 There are small differences around the edges.

The first is what to call Slade. The regional business press calls him the founder and says he started ENSEK with Stevenson and Kirk.1 ENSEK's own website listed him as "Founder & Chief Executive Officer."12 Tracxn, however, names only Stevenson and Kirk as founders and lists Slade as a former founder and CEO.7 Slade's own wording, calling the other two his co-founders, matches the company's version, and that version is the more credible one.

The second is timing. ENSEK's website was still promoting Slade as CEO and founder shortly before the change. Its pages for Enlit Europe 2026 in Vienna, where ENSEK is the official energy transition partner, said he had helped shape the event programme earlier in the year.15 The conference runs from 10 to 12 November 2026, so the new interim CEO's first major public event comes within days.12 That mismatch suggests the announcement came at short notice, not as part of a long, staged handover.

The third is size. Estimates put ENSEK at about 454 to 467 employees in mid-2026.716 That is below the roughly 550 reported after the Bulb platform deal.7 These figures come from third-party data providers, not company filings, so they should be read with caution. They do fit with earlier reports of some redundancies at ENSEK.6

Why it matters

For the UK energy-tech scene, Slade's departure closes one of the East Midlands' main software stories. A Nottingham start-up from 2010 grew into an international supplier of billing and customer platforms to energy retailers and was bought by one of Britain's largest energy groups.17 Founders moving on is normal, and ENSEK's case is a typical outcome for a strategic acquisition.

The bigger question is what ENSEK becomes under Centrica. The executive team has publicly pointed to international growth, flexibility services and AI-driven operations.1318 The company already offers a flexibility product aimed at the fast-growing market for distributed energy assets.4 Those plans need sustained investment and a CEO with a clear mandate from the owner.

For now, ENSEK has a capable insider running it on an interim basis and an executive team that is mostly less than two years old. The real test of the transition is still ahead. Whether the board, and Centrica behind it, confirms Rothery or brings in someone from outside will show whether ENSEK is meant to stay a separately branded growth business or move closer into its parent's operations.