Tayvallich fisherman and boatbuilder Hans Unkles has outfitted 6.40-metre potting boat Lorna Jane to run on solar power.
He has owned and skippered nine potting boats, andworks the latest of these on a part-time basis, fishing for lobsters two or three days a week. It was his expertise and a deep interest in renewable energy that led to outfitting Lorna Jane with solar panels to make it the UK’s first fully electric commercial fishing vessel.
‘I worry our fishing industry is missing the boat. With our current trajectory towards Net-Zero our vessels will be worthless. The process of wind and sun creating energy is fascinating to me, so I thought I could be the right person to give it ago,’ Hans Unkles said.
‘As a boat builder, I found the technical and physical aspects simple – just connecting wires from batteries to appliances. It’s purely the cost and administration which are the stumbling blocks.’
He commented that diverse requirements across the fleet segments means there is no-one-size fits all solution for vessels where emerging propulsion technology/fuel systems are concerned. In the interim, regulatory derogations, as with the Lorna Jane, will be necessary and considered on a case-by-case basis.
Lorna Jane only fished one season in very local waters before the conversion, so comparing fishing practices before and after the solar installation is data limited. He estimates that the vessel previously consumed 20 litres of diesel per day, to travel an average of 15 miles, costing around £20 per return trip.
Now it draws its power from a main battery bank, charged by four 460W bifacial solar panels which capture both direct sunlight and sea reflection. These provide power for propulsion and for the Spencer Carter hauler. Propulsion is a 10kW electric motor, derated to 4kW for greater efficiency.
Lorna Jane averages 26 miles per day, with its range depending on speed. On a cloudy day without solar input, this means a continuous range of 60 miles at five knots; reducing to 25 miles at six knots.
‘During the summer and up until the equinoxes, the solar input keeps up with all my needs. The boat charges while in use, and the days when lobster creels are soaking enables the batteries to recharge up to 90%,’ Hans Unkles said.
In winter, when solar power alone is not sufficient, the boat ties up at a pontoon that offers access to shoreside charging via a plug-in recharging point. This comes with a cost – a relatively high £0.75/kW plus an additional overnight mooring fee. The overall cost of powering the boat has now reduced to around £17 a day from July to December. In terms of electricity costs, Lorna Jane averages £10.12 per day.
The batteries have a 3000 charge-cycle specification. However, without the need for components such as impellers, fuel filters, oil changes, leaky pipes, water flow systems and alternators – all of which are susceptible to daily wear and tear – maintenance costs are expected to be substantially reduced.
‘I cannot put into words how much more relaxed your day is with a quiet boat. I had no idea how beneficial that was going to be,’ he said.
Lorna Jane was substantially modified before converting to electric operation, which took eight months. This involved deck raising and a new wheelhouse. Hans Unkles was in an unusual position when applying for Marine Scotland’s Maritime and Fisheries Grant – as both the fisherman and the boat builder.
Unfortunately, the available funding neither covered his time, nor the equipment already purchased, leaving him largely out of pocket. He believes the whole conversion cost approximately three times the value of an equivalent unconverted vessel with license. This highlights lays one of the biggest challenges associated with transitioning existing vessels to carbon-free steaming – how to make the figures stack up economically.
He also faced the challenge of needing to start the authorisation process from scratch with the MCA, to secure the necessary regulatory derogation, working closely with a senior MCA surveyor and his team, as well as employing a naval architect to submit time-consuming drawings. Although the process was lengthy, MCA successfully calculated how to apply existing codes of practice, making it easier for anyone in the future.
‘The project was refreshing, interesting and nourishing, it is the most satisfying boat I’ve ever built, and a total success,’ he said, commenting that he describes himself as optimistic about the shift to electric power, emphasising the need for fishermen to change their mindset.
The solar powered motor seems well-suited for the smaller under-10m inshore day-trip fishing boats that utilise static gear. With 2742 under 10m vessels operating across the UK in 2022 (Seafish, 2023), as well as aquaculture service vessels, solar power presents a potentially exciting solution.
