Pyebridge Overhaul Story


Following the first phase of refurbishment work at our Pyebridge 9MW flexible power generation asset (“Pyebridge”) successfully completed ahead of schedule, we were pleased to report that the site was back in production. This first phase of refurbishment also ensured that the plant passed its Satisfactory Performance Days (“SPD”) requirements under its existing T-1 Capacity Market contract (the “CM Contract”) and so retained the CM Contract’s associated annual gross profit margin income. Please refer to RNS announcements dated 11 April 2024, 26 April 2024, 7 May 2024, 21 May 2024, 13 June 2024 and most recently 1 July 2024 for further details (

Following the successful completion of the first phase work programme, we formally commenced with the larger and more comprehensive second phase work programme (the “2nd Phase”). The 2nd Phase is predominantly focussed on the complete overhaul of each of the Pyebridge site’s 3x Jenbacher reciprocal turbine engines (the “Engine” or “Genset”). The overhaul of each Engine will take approximately 6 to 8 weeks per Engine and comprise complete long-block and major parts replacements. Replacement Engine long-blocks will feature upgraded internal deflagration protection technology, which will significantly reduce the risk of potential damage due to engine backfires. The overhauls will ensure optimal overall generation efficiency, reduced operations- and maintenance costs and downtime, and optimal overall availability. Effectively, the Engines will be operating as though they were New engines with Engine clock operating hours set to zero when overhauls completed.

To give more insight into the work-stream involved in overhauling the Engines, an account of the four main steps carried out and now completed to overhaul the first Engine is shown below. As this process was completed seamlessly within the planned timeline and budget for the first engine, we expect the overhaul of the site’s other two Engines to proceed similarly and thus meet our target to have all three engines overhauled and operating optimally in due course.

Step 1: Removal of Old Engine from Site

The project started on 7 May 2024 by ordering a replacement engine long-block from the supplier PowerUp, in Austria, which had a lead time of 2 weeks. Once the order was placed, the High-Voltage (HV) supply cabling and switchgear were isolated, which allowed the team to start with the various tasks at Pyebridge to disconnect the multitude of supporting Engine components, piping, and cabling. Following the disconnection of the these supporting components, the existing Engine long-block was disconnected, removed by crane (as seen below), and transported to CooperÖstlund’s workshop in Northampton by truck, a distance of 71 miles, and arrived on 24 May 2024.

Step 2: Re-build of Engine at CooperÖstlund’s Workshop

The new block arrived at the workshop on 24 May 2024 and work started immediately with replacement and or refurbishment of the various Engine components onto the new Engine block. All critical components were replaced, and the Engine was fully refurbished and repainted.

Step 3: Re-installation of Refurbished Engine

Once the overhaul work at CooperÖstlund was completed, the overhauled long-block was transported back to the Pyebridge facility on 12 June 2024, whereafter it was craned back into its operational position. The final processes of this step were to reconnect the Engine with the supporting components on site, such as the control system, cooling system, lubrication system, etc., before full recommissioning of the Genset could take place.


Step 4: Re-commissioning & Commercial Operation of Refurbished Engine

Cold commissioning commenced shortly after the re-installation of the refurbished Engine were back onto the site, during which time the end-to end connections between the Genset’s instruments, valves and ancillary components, and the Genset control system were checked. Subsequently, hot commissioning and final testing officially commenced, where the Genset was calibrated under normal operating conditions. During this period, the Genset was calibrate and configured to ensure optimal performance.

The full overhaul process of the first Engine was successfully completed within budget and expected timeline, and the refurbished Engine officially started commercial operational running.

Photo 7: Refurbished Engine re-installed and re-commissioned in its engine cell ready for commercial operational running (28 June 2024)