The Application

Planet Neutral, a community interest company (CIC) based in North Yorkshire was recently tasked with returning a 5.4 diameter waterwheel in rural Perthshire back into service. The company who provides practical support to community projects focused on decarbonisation methods, got involved to assist the owner of the former mill in reducing carbon emissions associated with the site’s energy consumption.

The waterwheel which has been out of service for over 70 years is fed by a small pond next to the mill and a larger pond over the road which are topped up by drainage water from the local fields. The owner of the site, which is now a private residence, is keen to repurpose the watermill as a source of energy and utilise natural resources to run a sustainable home.

The Challenge

With no gauged or measured flow data and the computer models indicating low flow rates, it was clear that the waterwheel would never produce large amounts of energy. However, it could still serve as a valuable top-up system, particularly for heating. Its ability to offset carbon is maximized by integrating a Rotaheat solution, which efficiently converts motive power into clean thermal energy.

To address this, Planet Neutral partnered with Rotaheat, a UK-based company specializing in innovative heat generators that convert mechanical energy into heat.

The key challenge was to accurately measure the performance of the site’s feed pipe using a flow meter, as real-world site constraints—such as gradient, pipe diameter, and surface roughness—affect actual flow rates. While a computer model was used to estimate natural flow rates, determining the precise flow through the pipework was critical in specifying the mechanical equipment and the most suitable Rotaheat system.

Historically, the site has operated as a storage and drain system, which is why Rotaheat is expected to be a strong fit. While electricity is highly flexible, converting it back into heat is often inefficient—particularly in this location, where direct heat generation is the more effective solution.

The Solution

To solve this challenge, Planet Neutral approached Flowhire, the UK’s leading flow meter hire company with a requirement for a flow meter that could be easily attached to the pipe to establish flow rates over a certain period. They aimed to estimate the stored volume of water and conduct an analysis to determine the size of heat generator required. Based on the nature of the application, Flowhire’s KATFlow 200 clamp-on Ultrasonic flow meter was the perfect solution, thanks to its easy installation, no need for pipe cutting and built in battery-powered datalogger that records flow rates over time.

The Outcome

By implementing the Katronic KATFlow 200, Planet Neutral and Flowhire were able to accurately measure the flow rates and water volume to drive the waterwheel. This data was crucial in designing an efficient renewable energy system tailored to the site’s need. With the waterwheel back in service, the former mill can now deliver clean thermal energy, significantly reducing its carbon emissions. This project not only show cases the innovative use of decarbonisation methods but also highlights the potential for similar sites to save energy and contribute to a more sustainable future.

For more information on the services Planet Neutral and Rotaheat provide, please visit their website www.planetneutral.org Zero Carbon Heat | Rotaheat | Zero Carbon Heat

For more information on Flowhire’s Ultrasonic Flow Meters and applications, Click Here