Renewable energy as a source of mains electricity is well-established, but its part in providing off-grid power generation is also flourishing. Equipment of all kinds operate in locations where mains electricity is not available, and there is fast growing interest in the use of remote power supplies (RPS).

Dulas RPS development

One of Dulas’s long-standing activities has been collecting wind data necessary to optimise the siting and specification of wind turbines. This can be done by erecting Met Masts on which data-collecting instruments are mounted, or by using LiDAR devices, such as the Vaisala WindCube. WindCubes are relatively small, ground-mounted units, capable of taking wind measurements from across a range of heights. However, they need a continuous power supply, and are nearly always sited where mains electricity is unavailable.

Given our expertise in renewable energy, it was natural for us to develop our own RPS. Using solar panels and methanol fuel cells as its primary power sources, the resulting system has become integral to our WindCube installations.

A transferable technology

Having developed DuraSource as a necessary product to our wind monitoring business, it was clear that it could be useful in many other contexts. With funding from Innovate UK, we commissioned Energy Systems Catapult to compile a report on potential markets for our RPS. This flagged a wide range of possibilities, suggesting industries as varied as agriculture, construction, tourism, telecommunications, and security. From data logging equipment to remote switching, rural internet to security cameras protecting critical infrastructure and equipment, the potential is vast. In fact, we are already seeing examples of our RPS in use in a variety of new applications.

At the request of a water utility client, we designed and implemented an RPS that controls valves on a remote reservoir. Previously, when valves needed adjusting to match the river flow rates, the job required an operative’s visit. This incurred additional time and expense, and the site is difficult to access and carries safety risks. With the new system, the valves can be operated completely remotely at a fraction of the cost and without risk.

On behalf of a national infrastructure client, Dulas designed a tool that is being used to size RPS systems for warning signalling where a path crosses a railway line. Providing a reliable, inexpensive means of improving safety, this set-up has significant potential. If replicated across the country, as we hope, such installations will help to reduce incidents at these crossings.

Complex problem-solving

Designing an RPS is much more than simply putting a few solar cells and batteries together, perhaps with a fuel cell. Our Head of Consultancy, Andy Skipton-Carter, explains.

“Coming up with the optimum RPS for a given situation is an exercise in complex problem solving. Is power required continuously, as with gathering wind data, or are discrete bursts of power needed – such as those to open or close valves? Is an AC or DC current required? What installation challenges need to be overcome when many sites do not even have vehicular access? Then, once in situ, what external factors – weather, wildlife, human – could affect operation? An RPS needs to be robust enough to continue operating reliably whatever comes along.”