The electric boat Solar Sal 24 can sail all day only on sunshine. Of course it has batteries on board that can be used to power the boat after dark or when there is no sunshine, but careful attention to the natural world allows 10 people to enjoy a day on the water and never a drop of fuel burn or stop to recharge. It just might be the perfect way to be on the water and be a part of nature rather than hurtling through the natural world leaving a plume of pollutants in your wake.
Solar Sal is the brainchild of David Borton, a physicist and retired professor at Rensselaer Polytechnic Institute, who has focused on solar energy from the very beginning. His Sustainable Energy Systems in New York State focuses on solar energy and Borton has now made Solar Sal Boats part of that company. For him, an important benefit of solar energy is the opportunity to eliminate the use of fossil fuels that contribute to climate change.
He tells Arthur Paine about: Maine Boats he has been involved in the development of various aspects of electric sailing including DC motors, batteries, battery charge controllers, hull shaping and solar panels. He says Solar Sal 24 and other electric boats like it will allow mariners to enjoy uncomplicated, quiet and reliable performance, while maintaining a clear conscience.
A key factor for Borton is optimizing the overall efficiency of power through DC channels between the panels and the motor. When he combined all that with a specially designed hull, he applied for and received a patent.
Specifications & details
The Solar Sal is 24′ long and 7′ 6″ wide with a draft of only 1′ 8″. Just as electric car designers focused on aerodynamic efficiency to increase range, designer Dave Gerr focused on creating a hull that would glide easily through the water. He actually went back to the design of naptha-powered launches from the 1800s, whose needs for an efficient hull shape were similar.
The boat is powered by a 3 kW (4 hp) electric motor from Torqueedo, which also supplied 4 lithium-ion batteries with a total capacity of 14 kWh. The key to the electric boat is the canopy above it, which can accommodate 4 solar panels, each with a maximum power of 350 watts for a total of 1,400 watts. That is enough to sail around 5 knots all day without consuming the energy stored in the batteries. The list price for a Solar Sal is $124,500.
Why would you want one?
Borton is fully committed to solar energy and a sustainable planet. He lives in a house powered by solar panels on the roof of his shed. “I didn’t just want to prove something,” he says. “I wanted people to have a practical invention at their disposal, one that is good for the environment and one that can also be a commercial success.”
The first boats are built at Belmont Boatworks near Belfast, Maine. Owner Dan Miller has already completed two hulls waiting for customers. He says they will be ideal on lakes, especially those with speed or horsepower limitations. On many of those lakes, pontoon boats chug around all day at about 5 knots, but they burn gasoline all the time. A Solar Sal 24 would fit right in, at just the right pace to appreciate the scenery and without scaring the wildlife.
When fishing floats your boat [pun intended], you can do it all day at the ideal tow speed of 4½ knots while consuming only photons, electrons and bait. “The silence of the boat wouldn’t hurt your prospects or your neighbors,” says Arthur Paine. You also never have to worry about an explosion on board, something that is always possible with a petrol-powered boat.
Paine adds that while it’s technically a powerboat, “it appeals to the sailor in me because the boat is quiet, eco-friendly and uniquely suited to a lifestyle far removed from the worries of the coastal world, as no connection is needed.” is hooked up to the mains for charging, so independent of fossil fuels, you could spend weeks exploring the wilderness without worrying about accessing the next gas station or charging station.”
Although the solar panels charge less vigorously on a cloudy day, according to builder Dan Miller of Belmont Boatworks, the recharge rate is enough to go five knots all day. “That’s familiar territory for a sailor.” says Paine. “Another similarity with sailboats is that most sailors I know have a reputation for being frugal – a fancy word for cheap. As fossil fuels are getting more expensive, the owner of Solar Sal gets a permanent pass.”
Paine thinks these kind of boats could be used as ferries in sun-drenched places like the Bahamas. “There are many short ferries in the Bahamas where speed is not required, and workers, townspeople and tourists all day back and forth. Given the ample sunlight, a Solar Sal 24 could serve that route well. And you don’t even want to think about it. the price of gasoline [those places]† It is the first 100% solar powered boat to be approved by the US Coast Guard to carry passengers.
A bit of history
Sustainable Energy Systems has previously built a handful of one-off wooden boats in various sizes. Solar Sal 24, a fiberglass production boat, is the next step. In addition to the prototype, two more hulls have been built that are fitted out at Belmont Boatworks according to the customer’s wishes. Borton is experimenting with a fifth model, a 16-footer that actually flies with a modest 10 kW (13.5 hp) engine. His largest is a 44-footer that has been licensed by the Coast Guard to take fare-paying passengers for rides on the Hudson River from its home port in Kingston, New York. Another of his boats, a 40-footer, was cruising the length of the Erie Canal for freight.
That’s an important part of the story. A popular anthem from the days when the Erie Canal was a thriving trade channel featured this lyric: ‘I have a mule and her name is Sal. Fifteen miles on the Erie Canal. She is a good old worker and a good old friend.”
The 40-meter-long Solar Sal Two actually carried cargo on part of the original canal, the first time a sun-powered boat ever did the job originally assigned to mules. The name stuck. This video has some interesting historical photos to accompany the lyrics.
One of Borton’s concepts, a 27-footer built for Borton and his son, Alex, by Sam Devlin in Olympia, Washington, made the long pass through Alaska’s Inside Passage to Ketchikan and Glacier Bay. Although bright sunlight is a rarity there, Alex realized that as long as the sun came up, he didn’t have to worry about running out of gas.
People who own an electric car will recognize this next part. “It’s nice to have the variables of a electric boat, basically a mix of watt-hours stored potential in the batteries, balanced with kilowatts of replenishment coming off the roof. All electric boats have a “fuel gauge” in the form of a battery condition indicator. It is up to the driver to choose the right combination of speed and range. A smart operator of a Solar Sal can trade speed for range. With enough patience, a solar-powered boat always comes home,” says Borton.
Looking for a sustainable world
Probably nothing illustrates the difference between a sustainable world and a world that is depleting natural resources faster than they can be replaced than a sailboat. When you’re on the water, completely dependent on the wind (or lack thereof), a bond is formed between you and nature that simply cannot be replicated in a boat powered by an internal combustion engine. You will get there when you get there, and no amount of oaths or carefully made up epithets will help your progress one iota. A favorite expression among sailors is: “We can’t control the wind. All we can do is adjust our sails.”
There is a benefit that comes from letting go of the constraints imposed on us by our fossil fuel-powered environment and voluntarily submitting to the constraints of the natural world. It can give us a sense of calm and harmony and help us reconnect with nature in a way that is missing from many of our daily lives. Solar Sal 24 fits in nicely with that atmosphere.
Hat tip to Ken Anderson of Marblehead, Massachusetts, who first brought this story to my attention. Ken, Art Paine and I grew up sailing Narragansett Bay when ‘I Like Ike’ buttons were popular. It’s interesting how our early experiences intersect and come back to each other over time.
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