Ah, the blessings of San Francisco Bay: sunshine, sparkling water, brisk breezes, a multihull and a wing. In remembering the last America’s Cup, these could be the trimmings for a heart-thumping ride on foils at 40 knots. But this is a different show. No speeding. No grinding. No foiling. No body armor, crash helmets or cameras. And no profligate billionaires. This is not about speed.

The boat, a trimaran named Trillizas — Spanish for triplets — is vintage 20th century. Staring at the color of the wing too long could make your eyes bleed. Besides, it’s tiny and looks simplistic, compared to the monster wings on the America’s Cup cats. It doesn’t even have shrouds, stays or a sheet. If you spin the boat 360 degrees, this thing stays put, glued to the breeze like a weather vane. Even when the wing is “engaged,” as it is called, the boat only does about 7 knots. That’s with the engine. And nobody on board lifts a finger, except to fish for a hoagie.

Soporific parameters notwithstanding, this could be a game-changer. Yes, that’s right. Motorsailing with the assistance of a wing, not foiling at breakneck speeds, might be the wave of the future. At the very least it could impact millions of real people with real jobs and commutes that take them across water. If — and that’s the catch — if the numbers pencil out.

Trillizas, the staid Cross 42 trimaran with a single-element wing, is the experimental platform for Wind + Wing Technologies (windwing tech.com), a company that wants to demonstrate that wind-assisted ferries make economic and environmental sense. In that order. Nobody who runs a business goes green just for good looks or sainthood, but there’s much to clean up, so “winging it” just might work.

According to the Bay Area Air Quality Management District, the 140 excursion vessels and ferries operating in the area are belching 389.14 tons of “CO2 equivalents” a day into the atmosphere, plus particulate matter (0.34 tons/day), nitrogen oxides (7.81 tons/day) and reactive organic gases (0.69 tons/day). Ferries that also harness wind power — that’s the hypothesis — burn less diesel, thus emitting less particulate matter, fewer carcinogens and, of course, less CO2.

While that’s all good for the planet and the people on it, it has economic implications for operators who try to reduce the fuel bill to help their bottom line. They’ve been upgrading to clean and efficient but painfully expensive technology to hedge against a spike in diesel prices and, perhaps, the possibility of a carbon tax. But until further notice, the wind is free, and free always gets people’s attention.

“We’re still gathering data,” says Jay Gardner, the owner of Trillizas. He’s also the president of Wind + Wing and the initiator of the project. “We have been sailing for three months, five days per week, five to eight hours per day.”

Gardner, who also co-owns Adventure Cat, a charter business that runs two large sailing catamarans on Pier 39, built the shell of this 9,000-pound trimaran with his wife, Pam, for cruising. Stripped of its original rig, it now is an experimental platform fitted with a rigid wing that rotates freely on its vertical axis and doesn’t require lines for trimming or adjusting. It looks a bit unusual with a counterweight on a forward-jutting arm and a strut at the top that ends in a tail. The project costs are $355,000, covered by in-kind contributions from wing builder Photon Composites and Wind + Wing, plus cash from Adventure Cat ($25,000), BAAQMD ($33,000) and the California Air Resources Board ($135,000).

An all-star cast

Gardner has been pushing this idea for nearly a decade and awhile back commissioned Pete Melvin, of the multihull design firm Morrelli & Melvin in Newport Beach, California, with the feasibility study. “We’re taking thousands of people out on the bay every year, and our annual fuel bill is about $3,000,” says Gardner. “That’s why I have been thinking about using wind energy for other purposes, too.”

Melvin, who calculated energy savings of approximately 42 percent for a wind-assisted ferry, is convinced. “The necessary technology is in place. This is 100 percent feasible, especially in San Francisco with its strong afternoon sea breeze.”

He urged Gardner to look at wings because of their efficiency. And when electronics whiz and navigator Stan Honey introduced Gardner to Richard Jenkins, the pieces started to fall into place, starting with the wing. “It is completely autonomous,” says Jenkins, who designed and built the wing in a cavernous space on the premises of the former Naval Air Station in Alameda, where he operates two companies, Photon Composites and Saildrone (www.saildrone.com).

Jenkins is no stranger to speed. In 2009, in the Nevada desert, he set the absolute world speed record for sail-powered vehicles at 126.1 mph. Greenbird, the vehicle he used, looked nothing like Trillizas, but the wing was remotely similar.

However, putting a wing on vessels that sail to a schedule 365 days a year only works if it is so simple and smart that you don’t even know it’s there. It has to take care of itself, regardless of what the ship does. Hence, the lack of shrouds, stays and sheets. “The optimum angle for a wing is between zero and 15 degrees to the apparent wind,” Jenkins explains. “And that’s where it sets itself.” If the angle gets bigger, a wind sensor triggers the actuator that adjusts the tab up top, which pushes the wing back into its comfort zone. When the wing is not wanted — for example, while docking — the system is switched off via key fob (or manual override in an emergency) so it feathers to the wind.

The principle is KISS, but there’s nothing stupid about it. Smart and minimalist would better describe it: a small solar panel on each side, plus an inertial measurement unit, a computer and the actuator inside the wing, behind a hatch that is accessible from the deck. And the encoder that measures the angle of the wing to the ship’s centerline is installed below the deck-stepped mast.

Learning from drones

The wing produces only about 60 percent of the possible maximum thrust, Jenkins says, to keep things manageable during the trial phase. There’s no chance it will ever resemble a highly tunable America’s Cup wing that constantly needs human input. “You sacrifice efficiency for longevity and simplicity, which is key in this application,” says Jenkins, who also works with the Marine Science and Technology Foundation, which was founded and funded by Google boss Eric Schmidt.

For scientific purposes (i.e., gathering environmental data) and for potential surveillance missions (i.e., patrolling marine sanctuaries) he designed a drone with a wing. It aced the offshore test by sailing autonomously more than 2,000 miles from San Francisco to Hawaii while operating on as little as 3 watts. And some of the trickle-downs benefit the ferry project now — such as simplicity and robustness, since even a minor issue on an unmanned vessel would doom its mission. Or energy efficiency: If solar panels are the only source of power, consumption better be minimal. In his drone projects, Jenkins uses custom components that are optimized for extremely low power draw.

And that brings us to the fuel savings during our leisurely jaunt across San Francisco Bay. Motoring at exactly 7 knots, the wing was switched on and set itself to the proper angle. Right away, the numbers on the fuel-flow meter started to drop — down, down, down as low as 0.24 gallons per hour. “In 17 knots of true wind, we achieve a 60 percent reduction of the fuel burn rate,” says Gardner.

Sure, Trillizas is a low-drag cruising multihull, not a steel ferry that carries hundreds of people, but it’s enough to prove the concept. In a real-world application, the wing would be even better because it likes apparent wind, which would be in ample supply on a ferry that does 20 knots or more under engine power.

Very closely watching this was Jim Swindler, director of operations for Golden Gate Transportation’s ferry division, California’s largest ferry operator, with 2.6 million passengers annually. “We have seven ferries, four of them catamarans,” says Swindler, who shells out $6 million for the fuel his vessels consume in a year, roughly 1.8 million gallons. For him, a 40 percent reduction in fuel consumption would translate to big savings and small emissions, in that order.

“It is probably acceptable to present this as a hypothetical, but I’m not sure it is responsible without mentioning that the technology is still a long way from proven in a real-world environment,” says Swindler, who estimates it will cost millions to build a demonstration vessel and operate it in scheduled service for a couple of years. A 149-person catamaran with electric, diesel-electric or clean diesel engines and tandem wings is on the drawing board as a potential next step.

It’s potential because nothing will be decided until an independent data analysis tallies the numbers from the trials. But looking at the simplicity of Trillizas and her wing as she peacefully putters past Alcatraz, one can’t help but imagine a day in the not-so-distant future when large purpose-built catamaran ferries with colorful wings might be crisscrossing this magnificent body of water, leveraging cutting-edge sailing technology for a more sustainable future. Or, as Pete Melvin puts it: ”Knowing how the world turns, wouldn’t it be fantastic to come up with something that’s cost-effective and environmentally friendly?”

Indeed, it would. Never mind the order.

Dieter Loibner is sailing editor for Soundings.

July 2014 issue