Plant & Works Engineering
Engine overhaul provides Southern Water with sustainable CHP power
Published:  26 October, 2023

Finning, exclusive distributor of Cat engines and power solutions in the UK and Ireland, overhauled a CHP generator for Southern Water – helping the utilities company to benefit from a lower-cost and more sustainable way to power its operations. PWE reports

Southern Water operates CHP plants at a number of its wastewater treatment sites, many of which use Cat engines running on the biogas generated as a byproduct on site. This means the company benefits from greater availability of renewable energy to deliver the power it needs. At its Canterbury facility a Cat G3412 engine had been a remarkably reliable asset, running for an incredible 132,000 hours prior to the overhaul.

As the engine is so critical to the site operation the decision was made to remove and overhaul it instead of replacing it with a new one. Southern Water worked closely with its long-term partner Finning to consider the options available to them, as Andy Leather, Finning Customer Account Manager, explains: “We have worked with Southern Water for over 20 years, providing the engineering expertise through preventative maintenance and service agreements to keep their range of Cat generators running as productively as possible. With a detailed understanding of their business we were able to confidently recommend that the best course of action to maintain site availability within budget requirements was to overhaul the existing CHP set at the Canterbury waste treatment plant.

The overhaul involved removing the engine from its container on site and transporting it to the Finning Component Rebuild Centre (CRC) in Leeds. Here work began by disconnecting the alternator to then be reconditioned by specialist technicians, beginning a detailed process over several weeks to examine components and identify what further work would be needed.

This was achieved by stripping the engine down to the last nut and bolt. Cat certified engineers then cleaned and inspected each and every item to assess what could be reconditioned or replaced to ensure the engine ran like new. With this complete, it was then reassembled and given a fresh coat of paint. Post site installation, the engine was put through its paces to test performance and confirm it was ready to go back into operation.

The engine is now back working in Canterbury, and Southern Water are pleased to benefit from a more sustainable way of maintaining their CHP operations. Kenan Griffith, Southern Water’s Regional Maintenance Manager for Hampshire commented: “Finning has been a valued partner for many years, helping to keep engines like the Cat G3412 at Canterbury running smoothly far beyond what we would usually expect of a generator. Taking the rebuild route made sense to us on a few levels, not least due to the financial and environmental benefits.

“The assurance of knowing the work would be carried out by Cat certified engineers was also a big factor for us, as this assured us that the rebuilt engine would meet the same high standards as the original. We are looking forward to it running for years to come, and to undertaking similar rebuild projects with Finning for generators at other Southern Water sites.”