The electric motor and ‘range anxiety’Posted on Written by Eric Colby
When it comes to electric motors in a boat, people like the environmental friendliness. They love the super-quiet operation and even the instant torque. But one concern still looms.
“People’s perception is that the range or their ability to be out, compared to a combustion engine, is going to be limited, and it really isn’t,” says Marcia Kull, president of Torqeedo Group Inc. The company makes electric boat motors at its headquarters in Gilching, Germany, and its North American operation is based in Crystal Lake, Ill.
Kull refers to the worries about how far an electrically powered boat can go as “range anxiety” and says the concern can be overcome by educating people. As with many other alternative types of propulsion, people need to try it to see for themselves.
“That’s what helps people who may not be confident in the ability of the system to perform for long periods of time,” says Kull. Torqeedo has a 5.7-inch in-dash touchscreen that offers 14 applications. “It’s real-time information about your ability to boat and how long you can boat,” says Kull.
Torqeedo builds outboards, inboards, pod drives and hybrids, as well as its own batteries. One of its newest propulsion packages is the Deep Blue series of inboards, outboards and hybrids that the company says are the equivalent of 40- and 80-hp combustion engines. The Deep Blue 40i 1400 inboard and 40 R (remote helm) and 40 T (tiller) outboard make 33 kW and are intended for heavier vessels such as sailboats or tourism craft for commercial use. The Deep Blue 80i 1400 inboard and 80 R and 80 T outboards make 66 kW, which is equivalent to 80 hp, and are designed for pleasure use. The Deep Blue Hybrid system can be used with the outboards, inboards or in a sail-drive configuration. It has two high-voltage electric drives and a diesel generator that can be used to charge the batteries and actually be the power source for propulsion as well.
At the other end of the power spectrum, Torqeedo offers the 1-hp Ultralight outboard, which has become popular with kayakers. Kull says electric power lets a user stay out on the water longer and can help a kayaker get home if a wind comes up. Torqeedo’s most popular motors are the Travel Series outboards, which range from 1 to 3 hp and are used on sailboats and tenders.
It’s not as if electric power is a new concept. Elco introduced a production boat with an electric motor at the 1893 Chicago World’s Fair. The company still builds electric outboards and inboards in Athens, N.Y., and Dean Heinemann, director of sales, says people need to take a closer look at how much time they are actually running before they question range with an electric motor.
“People think they boat longer than they do when they are out on the water,” Heinemann says. “The secret of electric is that when I need the power, it’s there and I know if I manage it properly I can have a great day out on the water.”
Heinemann says Elco’s most popular outboards have been the EP-9.9 or EP-14 on up to an 18-foot pontoon boat and either the EP-14 or EP-20 on pontoons longer than 18 feet. On the inboard side, Elco is starting to see more interest in its EP-70 and EP-100 models, which replace 45- to 85-hp engines and 75- to 125-hp engines, respectively. Elco also offers what it calls a parallel system for boatbuilders or owners who want to repower with hybrid power. “Our system is compatible with any type of gas or diesel, with some small modification,” he says.
Regardless of the type of electric motor or the output, one of the primary reasons given for the increased interest in them is the recent improvement in batteries and their longer discharge times. “Battery technology is improving on a daily basis,” says Torqeedo’s Kull. Torqeedo recommends AGM for its Cruise outboards, and the company works with the automaker BMW to adapt its i3 batteries for Torqeedo’s Deep Blue packages. The Deep Blue batteries are waterproof to the IP67 rating and have been built to handle shock loads up to 12Gs. They are also guaranteed to be at 80 percent of their original life for as long as nine years after purchase.
Elco’s Heinneman says his company likes a deep-cycle AGM battery and recommends Victron, Deka or Lifeline. OceanVolt is a Finnish company with a U.S.-based facility in Maryland. It works mainly with sailboats, including catamarans, and the client list includes Alerion and U.S. Watercraft. Because the company frequently works with larger vessels, OceanVolt often uses hybrid systems with a diesel genset and electric motors. OceanVolt and Torqeedo offer the ability to recharge batteries when a sailboat is under way. With the propeller in neutral when the boat is under way, the spinning propeller charges the batteries. Torqeedo, Elco and OceanVolt all use conventional and solar chargers as well.
On the subject of batteries, another misconception is that a boat running on electric or hybrid power will need a whole bunch of heavy batteries. In a repower, all three companies say their system and the batteries they require would weigh the same as an inboard, requisite batteries and a full fuel tank.
What might surprise a person who’s new to electric propulsion is the instant availability of the engine’s power. There’s no revving or warmup required. Advance the throttle or step on a gas pedal, and a boat will leap forward. Anyone who has ever driven an electric golf cart knows this. The response is instantaneous. That’s why electric power is gaining a foothold in the commercial realm, where operators often need the power to move large, cumbersome vessels. Torqeedo engines power more than 40 commercial passenger barges that operate on the Riverwalk in San Antonio, Texas. “When you start looking at ways to move people and you add to it, ‘How can we reduce our carbon footprint?’, then electric propulsion is the way to go,” says Torqeedo’s Kull.
Lastly, there’s the question of price. It’s not an apples-to-apples comparison, but Kull says, “We use a rule of thumb that if your fuel costs exceed $1,200 per year, a Torqeedo Cruise model can save you money. If you spend more than $5,000 a year on fuel, a Deep Blue High Capacity is the way to go.”
Elco’s Heinneman puts it this way: “They’re paying for their fuel in advance, but they can make that investment last a long time if they just take care of the batteries.” He also recommends spending a little more on a higher-quality charger to maintain battery health.
When it comes deciding on electric power, Kull says people need to be honest with themselves. “If you want to water-ski all day long, electric propulsion isn’t for you,” she says. “For the vast majority of boaters who use their boats in lakes, near shore, fishing, pontoons, electric propulsion is a great solution.”
Greenline hybrid is a pace-setter
Greenline Yachts is probably the best-known builder of hybrid pleasure boats.
Greenline was recently acquired by SVP AVIO, a Slovenian company that was previously a distributor for the boats and for Shipman Carbon Yachts. Greenline is based in Slovenia, and SVP Yachts in Dania, Fla., is the U.S. distributor.
Greenline started building boats in 2008, and more than 650 models have been built since. About 75 percent of the boats have been diesel hybrids; the other 25 percent were straight diesel inboards. The Greenline Hybrid 33 has won 31 international awards, and the newer Hybrid 36 has picked up four.
The current hybrid system used by Greenline generates about 10 kW (14 hp), with the company’s Hybrid 48 drive motor producing a range of 20 miles at about 5 knots. Maximum speed is 6 knots, but the power draw at wide open is 120 amps. Maximum range for the hybrid vessel is estimated at more than 700 miles under electric power. Recharging the Li-Po battery with the diesel engine takes about two to three hours, and then you can run under electric power for as long as four hours.
The electric motor is bolted between the diesel engine and the ZF transmission and is about 2 feet long. It has freshwater jacketing to keep it cool. The battery in the Greenline 33 is a single 11.5 kW, and it’s charged with solar panels and the generator simultaneously under control of the boat’s battery management system.
All Greenline boats are constructed as Class B Vessels. The hull is vacuum-infused with solid biaxial S-glass and vinylester resin. Stringers and liners are cored with lightweight composites and chemically bonded to the hull and deck.
First tour boat to go all solar
Sustainable Energy Systems Inc., Gerr Marine and Riverport Wooden Boat School at Hudson River Maritime Museum have begun the construction of Solar Sal 44, the first passenger tour boat powered exclusively by solar energy.
Designer David Borton conceived the solar boat, and the commercial passenger vessel is the first of its kind. It’s powered by a Torqeedo 10-kW electric outboard and 16 SunPower E-Series solar panels. Solar Sal measures 44 feet, 11 inches, with a maximum beam of 10 feet, 10 inches. It displaces 13,500 pounds.
Borton has tested his concept on two full-size fully solar electric vessels that he built and tested — the 25-foot Sal and the 39-foot Solar Sal. Both boats are powered solely by solar panels and can reportedly run all day at 5 or 6 knots. The concept has a pending patent.
In 2016 Borton retained Gerr Marine to design Solar Sal 44 based on his concept. The larger boat maximizes the potential for Borton’s concept with a large battery capacity and optimization of the solar-panel configuration. A liveaboard cabin-cruiser version of the boat, the Solar Sal Cruiser, is also planned.
Solar Sal is designed to have the lowest carbon footprint. In addition to running on no fuel, the boat is built of wood-epoxy/strip-plank sheathed with fiberglass. This means that 95 percent of the hull structure is from the renewable, low-carbon wood. The styling of the boat is that of a late 19th-century launch.
The home waters for the boat will be around Albany, N.Y., where she will cruise the Hudson River and the Mohawk, Champlain and Erie Canal system. Solar Sal will seat 31 passengers.
This article originally appeared in the July 2017 issue.