When was the last time you pulled back the throttles to save fuel? Yeah, that’s what we thought. Cruising slowly to burn less sounds great — right up until you try it. Once you discover that the entire world is a no-wake zone, boating gets boring. Yet just as surely as the sun sets in the west, we boaters still love to pretend we’re green. We put oil-absorbing socks in the bilge, switch to phosphorus-free boat wash and keep that Y-valve cinched down tight. If we really want to clean up our act, of course, we need to burn fewer dead dinosaurs.
The automotive industry has made progress, thanks to hybrid technologies. And there are hybrid boat propulsion systems, such as those made by Steyr. But they are not yet widely available in production boats. That doesn’t have to stop you from taking advantage of electric power, free, from the glowing ball in the sky. Who says you can’t install some batteries, wire in a solar panel and use an electric outboard to transform any boat into a hybrid vessel? No one — so we tried it for you to see how it would work.
Many solar options have been proved effective on concept boats, which can run on 100 percent sun power. Perhaps the most well known is Planet Solar, a 102-foot long-distance cruiser covered in 5,780 square feet of solar panels that is currently circumnavigating the globe. In full sunlight, these create electricity equal to 127 hp and propel Planet Solar at speeds up to 10 knots. Hold on to your hat.
The mere existence of the boat may prove its point, but it also highlights some major-league problems with sun power. Firstly, it cost $26 million to build. Secondly, it isn’t exactly fast, especially when you compare its projected 32-month circumnavigation with the world record of 48 days, seven hours — set by a sailboat, for gosh sakes. Thirdly, Planet Solar was designed for a very specific purpose and won’t serve any other functions very well. You’re not going to use this boat, or one like it, for day cruising, running to the fishing grounds or tubing and water skiing.
Unfortunately, all three of these problems can carry over into the recreational realm. Solar-powered boats are usually expensive, limited in use and relatively slow. But in a few cases, solar still makes sense. Small electric launches in the 16- to 18-foot range, like those made by Duffy or ElectraCraft, have full canopies (read: plenty of surface area for solar panel mounting) and are used purely for shuttling people around at speeds of 5 or 6 knots. Solar gets the job done, and in this service, the savings on fuel costs pan out.
In virtually all other cases, hybridization makes a lot more sense than cruising purely on the sun’s rays. Since you have to go slowly some of the time anyway, why not make that time as environmentally friendly as possible? Use the sun to supplement when appropriate, and run internal combustion engines when you want it.
Very few boats are built specifically as hybrids, but one, the Greenline Hybrid 33, can cruise at up to 6 knots on electric power with six 1.3 kW panels in the hardtop and a lithium-ion battery array, or at up to 15 knots using a 150 hp diesel. Another real-world hybrid application that’s already in use is the harbor master’s boat in Annapolis, Maryland. The city’s patrol boat was retrofitted with solar panels on the hardtop and a Steyr diesel-electric hybrid engine last fall. It makes 5 knots without burning a drop of fuel, and since it spends most of its time in a no-wake zone, the boat’s running costs have been cut by about 50 percent. This “floating meter maid” runs about 1,500 hours a year, and significant savings are expected.