Solar-powered sunshine boats

The beneficial rays of the sun are what bring many of us to the warmth of the Riviera – and soon we may find a better use for surplus rays than roasting our backs on the beach, for which I hope most of us have more sense.

Solar-heated houses are becoming fashionable as the price of panels is driven down, and attention is turning to solar vehicles. Waterborne vessels offer great promise: they can be extremely wide like catamarans and decked with panels to soak up energy. Bikini-space was what I had on my three cruising catamarans, all berthed in Monaco. But volts beat bikinis in the boating business; the solar-powered boat has arrived!

Solar1 Monte-CarloPhoto: Solar1

Electric boats have been around since 1838, and the end of the century saw many on Europe’s waterways, cleaner and quieter than the smoky steamboats of the time. But the invention of the diesel and petrol engines killed them off until the 1970s with the arrival of solar photovoltaic cells, combined with concerns about fossil fuels.

Monaco gave a lead with the round-the-world trip of the big catamaran Turanor PlanetSolar 2011-12. And Monaco’s solar-powered “Bateau Bus” has ferried up to 50 people across the harbour for many years (at €1.50 per trip) though the 48-volt batteries are charged from the mains every night. Monaco is also the home of Venturi, global pioneers in electric cars, some with solar power added – the fastest is capable of 495km/h; in Germany the solar aircraft Solar Impulse 2 is preparing a non-stop round- the-world flight for 2015.

Boats need far more power than air or land vehicles because of water resistance. My own largest command (a Fleet Destroyer) had 40,000 horsepower to give 32 knots, but creating so much sun energy would require several acres of solar panels. Solar boats should be small and light, preferably hydrofoils, with the biggest possible array of solar cells. Such a design though is not optimal for either sea keeping or utility, as mega-yacht owners demand comfort as well as speed, and even the tenders often have to carry heavy loads of guests or provisions.

The Yacht Club de Monaco is organising the Solar1 Monte-Carlo Cup July 10-12, 2014. These races recall the canots automobiles regattas inaugurated just 100 years ago by Prince Albert I in 1904, and have attracted entries from the world over. The PlanetSolar (the world’s largest solar-powered vessel) will again be present in Monaco. Critics scoffed at Mr Rudolph Diesel in 1893 for his new motor for “horseless carriages” but diesel engines drive my boat, and now maybe solar power will too.