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Going Solar Is An Evolving Option For Boat Owners

Ra, named for the Egyptian sun god, completed the Great Loop with solar-powered electric outboards.

Ra, named for the Egyptian sun god, completed the Great Loop with solar-powered electric outboards.

When Capt. Jim Greer finished a 7,200-mile cruise this past winter, he acknowledged that he’d done something most boaters might consider crazy: completed the Great Loop without using fossil fuels or connecting to marina shore power.

Everything aboard his 48-foot trihull, Ra, was powered by Torqeedo solar panels, batteries and an electric propulsion system. “We could easily run all day on solar power when the weather was good,” Greer says. “We could also run on the batteries for extended periods of time without sunlight. Our longest single run was 142 miles in 42 hours nonstop, day and night, crossing the Gulf of Mexico.”

Solar power and its boating applications have evolved faster during the past few years than during the past few decades, experts say. What used to be an outlier energy concept that left some early saltwater adopters with rusted parts and cracked rigid panels is now a maturing industry whose products can make sense — and be affordable — for a growing number of boaters.

“In 23 years, the solar business, for the first 15 to 16 of them, it was very, very slow moving,” says Dan Kruger, president and CEO of RDK/Nature Power, whose solar products are sold at West Marine. “In the last four to five years it has skyrocketed. The cost went down so much that demand went up. People finally realized that it’s reasonably priced now. You don’t have to spend $4,000 or $5,000 to put a solar system on your boat. You can spend $1,000 and have a really nice system. You can spend a couple-hundred dollars and try it out.”

Speed demons need not apply; cruising at 40 knots for five hours straight still requires a fuel-chugger off the stern, at least for now. Even with the most efficient solar panels producing energy, the batteries where that energy is stored can’t keep up with the power draw that high speeds require. “The size or weight of the boat is not the issue,” according to a recent paper by Torqeedo. “It’s battery capacity. Higher speeds deplete the batteries faster.”

But for Greer and other like-minded boaters, who want to eliminate emissions and fuel costs while drawing on solar-charged batteries at a slower pace, today’s solar-electric systems are feasible. St. Louis-based Apex Marine has been offering solar versions of its pontoon boats since about 2013, working with Torqeedo to improve the electric engines that the panels power. And more recent evidence that a good number of saltwater powerboaters might be ready to trade speed for environmental friendliness came last year from Hinckley Yachts.

While not going solar, the Maine-based builder looked at market trends and invested in the creation of the 28-foot, 6-inch Dasher, a fully electric boat with dual BMW i3 lithium-ion batteries. The boat should hit about 27 mph but is expected to have a cruising speed of 10 mph with a 40-mile range when the first hulls are delivered this summer.

Hinckley went completely electric with the Dasher, which tops out around 27 mph.

Hinckley went completely electric with the Dasher, which tops out around 27 mph.

Based on those figures, the Dasher, at its most efficient cruising speed, will travel about as fast as Greer says he cruised at top-end capacity aboard the completely solar-powered Ra. “We recorded a top speed of 10.7 mph,” Greer says, “but we normally ran at 5 mph to optimize battery capacity, typically putting in a 30-mile run per day.”

A number of factors have coalesced in the solar industry to bring more products to market in recent years. First is that the efficiency of solar technology has improved. “Every square inch, you get twice as much power now,” Kruger says.

Future enhancements are also expected. About a year ago, researchers at the Technion-Israel Institute of Technology said they’d found a way to use thermodynamic tools that could boost a solar cell’s efficiency by as much as 50 percent.

The materials used to make solar panels also have evolved, making the panels semiflexible instead of rigid — a key design element for mounting panels on boats, which have curves and match up poorly with stiff, angular panels.

And while battery capacity for storing solar-generated power continues to increase, the cost of actually generating the power has dramatically decreased. Kruger says it’s dropped 75 percent in the past five years, while Torqeedo says it’s nosedived 85 percent during the past seven years. “This trend will soon make renewable energy more affordable than fossil-fueled power plants — it already is in some countries — and the cost barrier for renewable energy will fully disappear,” says Torqeedo.

Given these market shifts and big industries such as automotive, which are investing more time and money in advancing solar technology, new products coming into the marine space now make it possible for boaters to try solar power, even if they aren’t ready to embrace it fully.

Kruger says the required elements to get started aboard any boat are solar panels, a charge controller that protects the boat’s batteries from overcharging, and batteries to collect the solar energy. Existing batteries can work, with newer batteries offering ever-increasing capacity for energy storage. (The investment in new batteries can be offset by a reduction in maintenance costs with the elimination of fuel pumps, filters and other parts in the engine room.)

“It’s not a lot of stuff, and it’s as DIY as you can get,” Kruger says. “I’m not a DIY person, and I can hook up a solar panel. It’s plug-and-play. You plug in something, and you plug in something else, and it’s done. The hardest part of installing a solar project is deciding how you want to permanently install the solar panel.”

Boaters weighing the options of drilled holes, glue and bungee cords to mount the panels on wood, fiberglass or aluminum typically start looking for additional choices, Kruger says. At first, they may back off from a full-on solar installation and instead test the concept with briefcase-style solar panels, which are popular in the camping and RV industries.

The briefcase-style systems are just what they sound like: solar panels in carrying cases that come with features including adjustable kickstands and integrated charge controllers. Cruise to a remote harbor, unpack the briefcase and plug it into the boat’s battery system, generating enough solar power to run a few things on board.

Goal Zero has been a leading marketer of this briefcase-style solar technology, with a 200-watt version selling for about $575 online. West Marine sells Kruger’s 40-watt Nature Power briefcase solar panel for $179.

“These briefcase kits, we have models up to 120 watts,” Kruger says. “If somebody wanted a big system to really run things, then it’s not the right system for them. But if they want something that will recharge their batteries to run the GPS or some lights, or as backup power, then it’s a great option. And some people think of their boats as sacred. They are not putting glue on their boat or drilling holes in their boat, so this is an option for people like that. It’s another option for getting into solar.”

Nature Power’s semiflexible solar panels are easier to install than rigid panels and can be walked on.

Nature Power’s semiflexible solar panels are easier to install than rigid panels and can be walked on.

A similar concept applies to Torqeedo’s Ultralight outboards, which are designed for smaller tenders, kayaks and canoes. The Ultralight 403, which retails for $1,799, can be recharged with a roll-up portable solar array. Users typically buy a second battery, using one for cruising while the other battery charges. Because the solar array is portable, it can be left on the mothership, the dock or the beach, with the second battery connected to it. When the boater returns in the dinghy, a freshly charged battery awaits.

Kruger says that boaters, while perhaps slower to adopt solar technology than other enthusiasts, tend to be the smartest about the process once they make the leap. People who cruise know how their engine rooms work. They understand their power needs, and they want systems that are specified for the type of boating they plan to do — which is important because there is no one-size-fits-all solar system for all the types of boats on the water.

“They’re really educated,” Kruger says of boat owners. “They’re our biggest pain for customer service. They don’t accept a basic answer. They want to know more. They know a lot about their boats, and that makes them a perfect fit for solar.”

As more boaters find systems that work for their cruising needs, Kruger says, the market expectation is that cruising families will become as keen to go solar as families that drive around the country in RVs. Not only should improving solar technology ease fuel costs and maintenance issues, but it also can enhance the experience offshore, just as it’s changing that experience on land.

“There is a massive change in where you park your RV,” Kruger says of parks that welcome recreational vehicles. “You cannot run gas generators. Darn near 14 hours a day is quiet time. Some places are generator-free; they don’t want the noise. So solar is becoming really popular in RVs. Think about a marina. Who wants to hear the generators running all night?”

Greer, who cruised the Great Loop on solar power, achieved that quiet bliss with an array of 20 solar panels, each generating 245 watts, mounted on top of the boat. The panels provided enough power to run a Torqeedo Cruise 10.0 motor (comparable to 20 hp) and a pair of smaller Cruise 4.0 outboards (comparable to 8 hp each), with the solar energy flowing through two battery banks: one with four 12-volt AGM batteries and the other with eight, with both banks in a 48-volt configuration.

That kind of setup could appeal not only to longtime boaters interested in making the solar switch, but also to the next generation of boaters, experts say. As baby boomers age and, ultimately, cede their wealth to the next-biggest generation alive — the 80 million or so millennials who care a great deal about protecting the environment — boatbuilders will need products that make sense to eco-conscious consumers.

And that wave is expected to be tidal-sized, as reported by Bloomberg. A 2016 poll by the University of Texas found that 91 percent of those younger than 35 say climate change is occurring, and just over half supported a carbon tax.

“Many younger consumers were early adopters of electric and hybrid cars, and they will be more likely to favor the same propulsion systems in their boat purchases as well,” Torqeedo states in a recent paper. “Electric boating is safe, clean and quiet, consumes no fossil fuels and produces no emissions. It’s just a nicer user experience, overall.”

This article originally appeared in the March 2018 issue.



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