Normally, solar-powered boats make headlines only when they set some kind of new record. However, the question of whether it actually makes sense is hardly ever posed. As a result, solar-powered boats have shown that they are capable of circumnavigating the earth, yet this task can be accomplished much faster and cheaper by sailing boats (and this will probably always be the case, since one square metre of sail can produce up to ten times the power of the equivalent area of solar cells and, moreover, is available for 24 hours a day).

For this reason, the average sailor usually regards the owner of a solar-powered boat as somewhat obsessed. However, many sailing yachts would benefit from having an auxiliary electric motor for use in windless conditions, instead of relying on a diesel engine, which is expensive, heavy and maintenance-intensive. Furthermore, the requisite batteries can also be used for all other electrical appliances, which also renders the (sometimes problematic) gas-powered equipment superfluous.

In 2019, we equipped the Déjà Vu, a 9×4.2m sailing catamaran with 2×5 kW electric motors, 1.2 kWp bi-facial PV laminates and 40 kWh Lifepo4 batteries: it will be used as a micro-ferry in the eastern Mediterranean, where light winds prevail and a lot of solar energy is available.

Photos: Déjà Vu in late 2019, before and after installing the PV system.

See Projects – DÉJÀ VU for more information, photos and a video

But there is a kind of shipping where sails are impracticable and the combustion engine can be replaced by an electric motor: inland navigation. Whether the boat weighs 100 kg or 20 tons, solar power would be ideal here. Many canals have a speed restriction of 6 or 8 km/h in order to protect the banks. However, to be able to navigate the rivers both with and against the current, a solar-powered boat must be capable of travelling at 15 km/h for a sustained period.

Since 1990, we have been working on the development of solar-powered boats that can navigate even the strongest rivers in Europe. We have now covered around 50,000 km on Europe’s waterways, including the demanding route from Amsterdam to Basle with the Basilisk 3.