Europe’s largest waterwheel now generating electricity
A 9m waterwheel, installed on private land near Dorchester in Dorset, has become the largest such structure generating electricity in Europe, breaking the record previously held by one at a National Trust site in Port Talbot, Wales.
The galvanised steel waterwheel, which has 92 individual buckets carrying a total of 6 tonnes of water at a time, now delivers an average flow of approximately 150 litres per second, 24 hours a day, seven days a week.
The land on which the waterwheel has been installed is owned by Buckland Newton Hire, a family business specialising in plant hire.
Brad Perrett, BNH Manager and Director, explains, ‘As the lake is in front of his home on our family farm, my father wanted to watch a huge waterwheel from his window and we have made his dream come true, building the biggest wheel we can for him!’
The site to which the wheel supplies power includes more than 20 industrial units, many with large power demands, five other properties and offices. Currently the wheel supplies an average of 150 kWh per day, which represents around one-third of the total electricity demand on the site, a share that will rise in the summer when daily consumption is lower.
To achieve the required head for the project, BNH raised one of the lakes on the family farm by around 11m. The lake is supplied from a large spring and run-off rainwater from the valley slopes. The grounds around the waterwheel will now be landscaped by BNH so that visitors can come and view the project from summer next year.
In addition to plant hire, BNH also runs a number of related operations, including carrying out specialist groundworks projects. It has previously installed renewable energy – such as wind turbine, solar installations and hydro schemes – for some customers and was inspired to install its own waterwheel to power its business operations, nearby houses and family farm. The company is now open to repeating the success of the waterwheel project if requested.
‘We could easily have installed a cross-flow turbine,’ says Brad, ‘but we wanted to do something a bit different that showcases our capabilities and our green credentials as a company. We think we could replicate this project in the future to provide similar lake-based energy generation projects for clients.’
Apex Dynamics UK supplied the inline planetary gearbox used to control the waterwheel, providing it with near-perfect alignment, high efficiency and minimal power loss through transmission to ensure as much electricity as possible is generated.
Technical details:
An Apex Dynamics NB series linear 3 stage planetary gearbox is in line with the waterwheel shaft and is connected to the generator via a pulley and belt system. The waterwheel rotates at 4.5 rpm and the Apex gearbox provides additional flexibility to fine tune the speed up to 450 rpm at the 48 mm gearbox output shaft.
The high torque from the waterwheel is accommodated at the 140 mm diameter input shaft of the gearbox. Getting the shaft size to match was very important to the project. Having incorporated a flexible grid coupler into the system design to accommodate any misalignment, this has proven unnecessary because the NB servo gearbox perfectly aligned with the input and output shafts but has been retained as a safety feature. The pulley and belt connection delivers the required 1500 rpm to the generator.
Apex Dynamics UK’s John O’Malley said: ‘As a Customer Service Manager with an overview on key applications for our servo gearboxes it is great to be involved in Europe’s biggest electricity generating waterwheel project, supplying a core component. Apex Dynamics is a pioneer in the gearbox industry, with our high-value motion control solutions and the NB Series was the ideal fit, capable of handling up to 45,000 Nm of torque. Partnering with the team from BNH on their landmark project was a rewarding experience and showcases what is achievable with our precision servo gearbox technology.’
