Solar-powered Vessels Becoming a Reality
David Borton, a retired adjunct associate professor of mechanical engineering at Rensselaer Polytechnic Institute in Troy, NY, has a passion for solar energy, which has found its most recent expression in building solar electric boats.
His first solar boat, assembled ten years ago, used the hull of an old 20-foot Grumman canoe and is still being used as a pleasure launch at his family’s Adirondack Mountain camp, started in the 1890s by his great grandfather. He’s built three other solar boats since; first was Sirius Sun, then Sol, a 25-foot wooden launch, in 2013.
Sol has been instrumental in demonstrating the possibilities and promise of solar electric boating; she’s given tours of the Hudson and Erie canals, run in the Wye Island Electric Boat Marathon, and participated in wooden boat shows.
Borton’s intent with was to prove the practicality of a solar workboat, but many opined that solar electric power was only useful for small boats. Never one to back down, Borton did the math and figured that a 40-foot vessel would have roughly 2.5 times the surface area available for solar collection. He designed a wooden, strip-built hull that could be fitted out as a 12-ton cargo ship, a dayliner tourist vessel or as a cabin cruiser, all using nothing but free, clean solar fuel.
Christened Solar Sal, his first 40-footer is named for the famous song, ‘Fifteen Miles on the Erie Canal’. The song memorializes Sal, one of the mules that towed the barges that brought economic prosperity to New York in the mid- to late-1800s.
Economic growth is hard to come by these days, but its pursuit built an unlikely public-private partnership between Borton and a local school district.
Facing declining enrollment, Schodack District School Superintendent Bob Horan offered unused space to small businesses and non-profits, hoping to build good relationships in the community and inspire his students with real-world applications for their studies. Solar boat construction was a great fit.
First they looked at a space in the basement of the middle school, but there would be no way to get the vessel out, once built. That led them to the bus garage. The partnership resulted in middle and high school children — and the community — coming together to help construct Solar Sal. A local retired house builder, Ed Joyner, took a particular interest and worked side by side with Borton daily building compound curves instesd of plumb houses.
Solar Sal was launched recently for a festival celebrating the 100th anniversary of the enlarged Erie Canal. Initial data finds she runs at 13.4 km/h on twin Cruise 4.0 electric motors and cruises at half throttle. The motors are manufactured by Torqeedo, a German company that produces electric motors from 1 to 80 horsepower.
The 4.0 Cruise motors provide the equivalent thrust of two 9.9 horsepower combustion engines, but these powerful, emission-free electric motors run on sunlight. Sal can motor all day in daylight and up to 50 miles after sunset on stored battery power. She is fitted with 5 kW of solar panels, serving two battery banks. One powers a bank of Torqeedo’s Power 26-104 lithium batteries, the other powers conventional lead-acid batteries. Borton hopes the side-by-side comparisons of the storage technologies will provide some interesting data in the future.
Solar Sal has a packed schedule this year, visiting local festivals and alternative energy conferences. Her mission? To carry forward Borton’s goal of proving that solar propulsion is not only environmentally and budget-friendly, but on vessels for cargo, tourist day-lines and ferrys as well as cabin cruisers.
For more information on Solar Sal or how to have a solar boat of your own built, contact David Borton. To find out more about Torqeedo’s electric motors, visit www.torqeedo.com.
Original Source; Sportsmans Lifestyle.com