A new solar-powered water heating system will help dairy farmers to cut energy costs and reduce consumption, using Internet of Things (IoT) technology to improve sustainability and efficiency.

Glasgow-based Soltropy – a specialist in solar thermal technology – has designed and developed a smart monitoring method for its water heating system through the Milk Round accelerator hosted by CENSIS, Scotland’s innovation centre for sensing, imaging, and IoT technologies. The initiative is part of the Digital Dairy Chain, a multi-partner project led by Scotland’s Rural College (SRUC) which aims to transform the dairy processing supply chain in south and west Scotland, and Cumbria. The project is funded by UK Research and Innovation’s flagship Strength in Places Fund.

For dairy farmers, access to hot water is essential for regular cleaning and sanitisation of parlour floors and equipment but traditional water tank heaters consume significant amounts of energy. In contrast, Soltropy’s roof-installed system uses energy from the sun and a series of solar thermal panels to provide plentiful hot water on demand. Estimates from the company suggest farmers could make savings of up to £6,000 per year in energy bills, depending on their supplier.

Soltropy's heat-generating solar thermal panels are three times more efficient than photovoltaic panels, which convert sunlight to electricity. Unlike other solar thermal systems, Soltropy's panel needs less maintenance and, crucially, do not require antifreeze, a major obstacle for widespread use of solar thermal systems in the UK as antifreeze needs replaced every three years.

The latest generation of the heating technology - which can easily be retrofitted on to existing systems - will feature IoT-connected solar tubes to enable remote monitoring. A typical farm setup is around ten times the size of an average domestic system and data collected will help farmers to monitor the system's performance. Automated alerts will point towards errors and necessary repairs, rather than relying on a physical inspection of the panels and solar tubes to ensure optimum performance. Over time, analysis of the data could move from highlighting faults to predicting when maintenance is needed. 

For dairy farms, which can be based in remote, rural locations, the system also provides an alternative off-grid option for renewable energy. The thermal technology can also be applied to other businesses and sectors with large requirements for hot water, such as hospitality and tourism destinations.

Stuart Speake, managing director of Soltropy, said: “The introduction of IoT and sensors is a big development in our sustainable solar thermal technology and will make it much easier for users to keep on top of system maintenance and performance. The first generation of the system is already used at a number of sites in Scotland and we have seen how it can reduce energy costs and fossil fuel consumption. Using IoT will only add to this, and we hope to see the new connected version installed across sites all over the UK, helping the sector’s transition to net zero.

“Taking part in the Milk Round accelerator programme represents a big step forward for the business and, combined with the expertise and support from CENSIS, will help us scale-up and could lead to the development of new business models that level the playing field for customers to use solar thermal energy.”

Following tests of the new system by Heriot-Watt University researchers, Soltropy plans to complete an on-farm trial. The product is expected to be available on the market later this year.

Rachael Wakefield, business development manager at CENSIS said: “IoT technology can help traditional sectors and industries like dairy farming to transform processes and ways of working to boost efficiency and improve sustainability. In this case, it is great to see a system that is designed and built in Scotland, by a Scottish company, incorporating IoT technology and delivering valuable impact for users which will, in turn, lead to growth for all involved.”

Stuart Martin, Programme Director for the Digital Dairy Chain said: “The Soltropy project encapsulates everything the Digital Dairy Chain aims to achieve through the Milk Round Accelerator programme. It brings cross-industry innovation and technology into the dairy sector to ensure sustainable production and processes. We welcome discussions from anyone who believes they have a solution to a dairy industry challenge or believes their technology is transferable into the sector.”