David And Alex Borton: Powered By Sunshine

David and Alex Borton made popcorn on their single-burner gas stove while considering what to do. They were more than halfway through Grenville Channel, a 45-mile-long strait along Alaska's Inside Passage, but there wasn't enough sun to replenish their batteries. The father-son crew was attempting to cruise from Bellingham, Washington, to Ketchikan, Alaska, on their custom 27-foot Down East-style cruising solar-electric boat, Wayward Sun.

"We need to charge the batteries," David said from the helm. "So, we have to figure out where we're going to stop, when we're going stop, and how much battery we're going to use." With no diesel or gas engine for backup, you might think he'd be concerned. He wasn't. Just as a sailor waits for wind, David and Alex wait for sun. It's all part of long-distance cruising on a solar-powered boat.

David, a retired solar engineering professor from Rensselaer Polytechnic Institute, devoted his career to solar energy research and teaching. A lifelong boater, he grew up in canoes and Adirondack guide boats, working in the family's wilderness guiding business. Combining boating and solar power was a natural fit.

Over the last 17 years, the Borton family built several custom, patented solar-electric boats, ranging from 16 to 44 feet. "The first couple were experiments to prove the concept," says David. In 2011, they built a 25-foot wood-strip boat. Alex found the design and did the lofting. David and his wife, Harriet, also a physics professor, built the boat, twisting and bending every wooden strip themselves. Their fourth boat was a 40-footer, on which David and Harriet made a 750-mile round trip on the Hudson River to the Niagara River via the Erie Canal. In 2019, they built a 44-foot passenger boat for the Hudson River, Solaris, which they say became the first U.S. Coast Guard-certified commercial 100% solar electric tour boat.

Alex shares Harriet and David's sense of adventure and love of boating. "I've done several expeditions on motorless boats, including a two-week trip down in Patagonia in South America on a 20-foot open sailboat that only had oars for backup," Alex says. He's also worked as a wilderness guide, outdoor educator, and wilderness therapist. Today he runs a private therapy practice in Bellingham, Washington.

In 2018, Alex decided he wanted a solar boat of his own. He teamed up with Olympia, Washington, boatbuilder, Sam Devlin, renowned for his graceful designs and for being an early pioneer of the stitch-and-glue method of building. To power the boat, they chose a Torqeedo Cruise 4.0 electric pod drive powered by six Torqeedo Power 24-3500 lithium batteries, and a 1,700-watt array of solar cells are on the boat's rooftop.

The idea for the trip to Alaska came later. "As a sailor, I've always wanted to do the Inside Passage," says Alex. David had a different reason for going. "I was a logger in Thorne Bay, Alaska, one summer in 1963," he says. "I wanted to go back and see it."

They departed Bellingham on May 25, 2021, along with Alex's son, Kai, who joined them for the first night of the voyage. "It was wonderful starting off with the three generations together," says David. They spent the entire time aboard, anchoring at night, as they were not permitted to go ashore in British Columbia due to Canadian COVID-19 restrictions. They made landfall on Ham Island, 15 miles southeast of Ketchikan, on June 13.

"We'd made it, and had popcorn to celebrate," says David. They'd completed what they believe to be the first-ever solar-powered voyage through the Inside Passage from Bellingham to Southeast Alaska, then continued up the coast to Glacier Bay and Juneau, Alaska.

"Getting into Glacier Bay was the icing on the cake," says David. Always a family affair, Harriet and Kai flew out to join them.

For most of their trip, the weather was cloudy or rainy. The challenging weather conditions provided the perfect testing grounds for their solar setup, and they weren't disappointed.

"The solar-electric system has more than exceeded our expectations," says Alex. "During the 45-day passage to Juneau, we were underway for 38 days. We averaged 32 nautical miles per day at an average speed of 3.7 knots. While some days we stopped early or left late due to weather, there were only two full days we didn't travel at all due to high winds or dense fog."

Even on completely overcast days, they could average 2 to 3 knots without drawing on the batteries at all. With direct sunlight, they estimate they could do 5 knots all day without battery use.

"People would always ask, 'How far can you go?' They're thinking of a normal electric boat, where you need to have a lot of batteries and come back to plug in," says David. "We went 1,400 miles. There's no range anxiety."

Since returning home, the Bortons are developing their Solar Sal boat lines. "The mission is to make solar boating affordable and practical," says David. "You don't have to be a physicist to go on a solar boat trip," he said. "You can just have a solar boat."