Major anaerobic digestion plant upgrade completed at the Isle of Wight
We’re proud to announce the successful completion of a significant upgrade at our Isle of Wight Anaerobic Digestion plant — a key milestone that enhances both operational efficiency and long-term resilience of the facility.
The extensive works, carried out over recent weeks, involved a full overhaul of the primary digestion tank and supporting infrastructure. The upgrade was carefully planned and executed to ensure minimal disruption, future-proof the system, and boost overall plant performance.
Plant Manager, Mark Ridett, said: “Buttercup had a stomach ache, but she’s now back to full health after a full check-up and some expert care!”
The Works
The upgrade began with the erection of scaffolding around the perimeter of the primary tank, enabling safe access for the complex internal works that followed. The tank was emptied into an on-site storage tank, allowing safe removal of the roof membranes and careful pumping out of substrate levels until access could be gained for excavators and machinery.
Once inside, a fleet of equipment, including excavators, a Bobcat, and a scissor lift, was lowered into the tank. The team worked efficiently to excavate the tank contents, with solid material conveyed and removed via hatch, and liquid substrate pumped out and responsibly spread on nearby agricultural land in compliance with environmental best practices.
The team also carried out a deep clean and inspection of all internal piping, unblocking, extending, and modifying the main feed system. This included alterations to previously redundant pipework, allowing for flexible mid-level feeding options in the future.
New equipment, greater efficiency
At the heart of the upgrade was the installation of a PTM Phantom 2500 slow-revolution flowmaker mixer, featuring a powerful 2.5m diameter blade, a critical improvement that enhances substrate mixing while reducing energy consumption and maintenance demands.
The remaining mixers were thoroughly checked, with a lifting cable replaced and operational tests completed to ensure a full range of motion and directional control.
Behind the scenes, the heating system was cleaned and inspected, confirming there were no leaks, and the desulphurisation net was cleaned and reinstalled.
Structural inspections were also conducted across the tank, with all components found to be in excellent condition, confirming the tank’s integrity for years to come.
Once all internal work was completed, the team safely removed all machinery, refitted net straps, and reinstalled the roof membranes along with a new non-return air valve and pipework system.
The access hatch was sealed, the site and equipment were fully cleaned, and a new crushed concrete surface was laid between the tanks to address site access issues caused by heavy rainfall during the works.
Safety first, and a bit of humour
All work was completed without a single accident or incident, fully in line with health and safety standards. The professionalism of all involved ensured the project ran exactly to schedule, despite the challenges of working in a live, weather-sensitive environment.
And while the technical work may be finished, some site personnel report that the toughest job may still lie ahead: convincing their partners to come near them again after a few long days inside the digester tank!
What’s next?
With the upgrade now complete, the Isle of Wight plant is operating at full capacity. The site is now equipped for:
- Longer maintenance intervals (now every 6 years instead of 3),
- A new engine reset to zero hours, giving 60,000 hours of life,
- And with the improved access and pipework layout, ReGenEarth is positioned to integrate systems like the Sandcatch ‘snake’ system, ensuring no production drop during future maintenance or tank cleaning.
This investment reflects ReGenEarth’s commitment to optimising renewable energy infrastructure, delivering sustainable solutions, and pushing the boundaries of circular resource recovery. The Isle of Wight plant continues to be a flagship site, now stronger, cleaner and more efficient than ever.
