Solar power is increasingly becoming a feasible choice for powering electric boats. In the last decade, we’ve seen improvement in the efficiency of electric boat motors, lithium-ion batteries, and the efficiency of solar panels.
In 2010, the Tûranor PlanetSolar, a huge catamaran yacht powered by 470 square meters of solar panels, was unveiled by New Zealand’s LOMOcean Design. It became the first solar-powered vehicle to circumnavigate the earth, when it finished a world tour. The name Tûranor, derived from J.R.R. Tolkien’s novel The Lord of the Rings, translates to “The Power of the Sun”.
On a less grand scale, solar-powered boats are becoming available in the consumer market, driven by the introduction of lithium-ion marine batteries. These batteries have been mostly used to power small electronic devices, but now large-scale lithium-ion batteries are available for boats. Lithium batteries deliver four times the energy per pound of battery weight when compared with conventional lead acid, gel or AGM batteries. They also last about three times longer than conventional batteries (up to 10 years), and less susceptible to shocks and temperature extremes.
A German company, Torqeedo has introduced high-efficiency boat motors come with lithium-ion batteries pre-installed. Torqeedo offers a range of motors that connect to crafts of all sizes — everything kayak motors, to large outboard motors with the equivalent of 20 HP of thrust, capable of powering boats up to 6 tons in weight.
Torqeedo also has a line of solar products available — it recently introduced powerful lithium-ion marine batteries that connect to marine-ready solar panels. The batteries have a capacity of 2,685 Wh and weigh 44 pound.
Sea Eagle, a maker of inflatable boats, also offers a solar panel that connects with Torqeedo motors. Sea Eagle says the Travel 1003 Torqeedo motor can be combined with a Sea Eagle Solar Panel, and this panel will completely recharge the lithium-ion battery in less than ten hours. The solar panel also charges the battery while the motor is being used. The 45 watt solar panel can be mounted on canopies on dinghies, transom and pontoon boats.
The Travel 1003 Torqeedo motor can monitor your sailing speed with built-in GPS, and the display panel also shows the status of the charging battery. The Sea Eagle Solar Panel is made by US company PowerFilm. It measures 58” x 36” and can be rolled up for storage when not in use.Torqeedo products are available online at West Marine.
Powerfilm Flexible Solar Panels are available at Amazon.
Book that covers solar sailing: Sustainable Sailing: Go Green When You Cast Off by Dieter Loibner
Wikipedia entry: Electric Boats