A View from Here

Bill's Sisson's weekly Trade Only blog

A boat is not a Prius

A story in The New York Times several days ago talked about the negotiations between the auto industry and the Obama administration over new vehicle mileage and emission standards that would dramatically affect the types of cars we drive in the future.

The proposed mileage standard would require American cars and trucks to meet an average as high as 56.2 mpg by 2025, which the story points out is about double the current level.

Reaching the higher standard would require a large increase in the number of electric or hybrid vehicles consumers buy, according to industry experts. And although the industry says it can develop cars to meet the standard (at a cost in the billions), one auto lobbyist asked: “The question is, will consumers buy them?”

In other words, will Americans embrace a smaller, lighter and possibly more expensive set of wheels? Even one that collectively will save them billions at the filling station, as the story notes? The jury remains out.

What about hybrid power in boats? Is there a lateral transfer of technology that will improve efficiency in marine? We might be talking apples and oranges.

Hybrid power may sound sexy, but don’t get caught up in the hype when the application is for boats. That’s the message of naval architect and yacht designer David Gerr, director of the Westlawn Institute of Marine Technology.

“Hybrids are not the answer for boats,” Gerr says in an interview in the August issue of Soundings magazine, the sister publication of Trade Only. “They work very well for cars, but they do not for boats.”

In terms of efficiency, Gerr told us, “they are a dead loss in almost every instance on a boat” — trawlers/displacement hulls might be the exception — “in spite of the hype.”

Boats simply don’t receive the same benefits that cars do from hybrid systems. “Land vehicles generate savings when braking or coasting downhill,” Gerr explains. “Boats never get that benefit — at all. Land vehicles spend a lot of time at idle speed or stopped in traffic. Boats don’t normally operate like this. In those cases, a hybrid [land] vehicle runs on electric alone. Boats don’t get the opportunity.”

And on a more fundamental level, Gerr says, the loss of power that occurs when you convert or transition from one energy source to another with a hybrid system — chemical to electrical to mechanical — is significantly greater than with a standard direct-drive diesel or gasoline engine installation.

There’s another aspect to hybrid power that Gerr says is rarely discussed: the initial expense and the complexity of the systems. At Westlawn, students looking at propulsion systems are asked to analyze both the initial and operating costs of a gasoline and diesel installation on the same boat.

“Our students are often flabbergasted at how many thousands of hours it may take to make up the difference in cost between a diesel and a less expensive gasoline engine,” Gerr says. “Most yachts are not used that often, so it could be a dozen years before you make up the cost. With these hybrid installations, it is far more expensive than that. To make up the difference in cost is almost impossible at times.”

There also are maintenance and repair considerations. “You take these complex diesel-electric systems,” Gerr says. “Some are really ingenious, but where do you find the mechanic that truly understands it? And where do you find the parts?”

Gerr says following tried-and-true formulas will produce dramatic increases in efficiency. “There’s no mystery to it,” the naval architect says. “Any designer worth his salt knows that if you want to make a more efficient boat, a longer, more slender boat is always more efficient. If it is properly proportioned, it’s also more seakindly. Also, a key is to operate the boat at a little slower proportion of its total hull speed.” Optimizing the propeller and drivetrain also is important.

Unfortunately, Gerr says, this doesn’t have the sex appeal that the fancy, high-tech hybrid stuff does, but it works. One downside: You’ll pay a penalty with a longer boat in dockage fees.

One more truism: There are no free rides.

Comments

10 comments on “A boat is not a Prius

  1. Cap'n Crunch

    The point is well taken. Less could be so much more. All we have to do is learn to walk the walk. So how about a little skiff, a simple lug rig and a pair of oars? That’s as hybrid as it gets.

  2. David

    It’s about time someone started applying some common sense to the hybrid concept regards marine applications.

  3. Jim Bower

    How about measuring fun for the dollar. I have a Nordic Tug 42. A wonderful boat. However, the best fun for the dollar boats were a 10′ Mayflower ($300), a 12′ Widgeon ($500), and an 8′ kayak ($300). Of course, this attitude would further destroy our boat building business.

  4. LARRY

    A “YES WE CAN” ATTITUDE MAY HELP SOME, FOR IF THINKING OUT OF THE BOX WAS EVER IMPORTANT OR NEEDED, NOW IS THE TIME! I FOR ONE HAVE NEVER CONSIDERED THE LACK OF POSSIBILITIES, PERHAPS IN THE PRESENT SHAPES, FORMS, AND DESIGNS, IT SEEMS IMPOSSIBLE. BUT MAYBE CHANGE IN THOSE AREAS IS REQUIRED FIRST. TRUE THERE IS NO FREE LUNCH, AND EVERYONE KNOWS GOING SLOWER SAVES, NO BIGGIE THERE.
    WE HAVE REACHED THE LIGHTER MATERIALS AGE ALREADY, AND MAKING SUPER STRIDES STILL IN THAT AREA. PERHAPS HUMAN CONSCIOUSNESS IS ALSO AN AREA WE NEED TO EXAMINE AND EXPLORE FURTHER. STEAM ENGINES WERE DIFFICULT, BULKY AND DANGEROUS, HOWEVER I BELIEVE FROM AN ENVIRONMENTAL STANDPOINT, CONVERSIONS AS HYBRID, MAY ALSO NEED FURTHER EXAMINING. OUR NAVY RUNS ON NUCLEAR, NOT QUITE THE ANSWER, BUT IT WAS ACHIEVED WHEN IT BECAME A GOAL WITH FEW OTHER OPTIONS.
    LITTLE DOUBT ABOUT CONDITIONS IN THE OCEAN REQUIRING ADDED ENERGY, BUT WHEN I LOOK IN THE MARKET, THE LARGE NUMBER OF VESSELS BEING OFFERED TO THE PUBLIC, WITH MULTIPLE FUEL GUZZLING POWER OPTIONS, I SHAKE MY HEAD SEEING THE LACK OF COMMON SENSE THERE. SURE WE ARE CATERING TO THE “GO AS FAST AS YOU CAN” EGO OF MANY, AND THE NEED FOR SPEED INSIDE THE YOUNG AND OLD ALIKE.( who have yet to grow up), WHO HAVE LITTLE CONCERN FOR EVERYTHING ELSE, INCLUDING CLIMATE CHANGE.
    NO EASY ANSWERS, AND HYBRID MAY NOT BE ONE OF THEM EITHER, BUT SOMETHING HAS TO GIVE, AND A $300 KAYAK IS NOT IT. (however lately I’ve had lots more cheap fun I ever imagined in my small 14ft W/ 25HP 4 stroke O/B, but of course as long as I stayed close to shore)
    YEARS AGO THERE WAS WORK BEING DONE IN DEVELOPING ON SOME SORT OF AIR WING “SAIL”, WHICH WORKED TOGETHER WITH A FUEL ASSIST POWER, BUT NOT MUCH WAS HEARD AS TIME WENT BY, AND FUEL STAYED CHEAP ENOUGH, NOT TO CARE ABOUT SAVING IT.
    FOR HUNDREDS AND HUNDREDS OF YEARS, USING SAILS WAS “THE” WAY. BUT THAT TOOK “WORK, SKILL AND KNOWLEDGE”, IT WASN’T AND STILL TODAY, NOT FOR EVERYONE.
    A SONG COMES TO MIND, (I know it my have little to do) “THE ANSWER IS BLOWING IN THE WIND”
    TIMES FOR A CHANGE ARE MOST CERTAINLY UPON US, HARD QUESTIONS, AND HARDER CHOICES LURK AHEAD. THE AUTO INDUSTRY IS FINDING WE CAN STILL GO 60 TO 70 MPH WITH SOMETHING ELSE BESIDES GASOLINE OR DIESEL. THEY STILL HAVE A TOUGH ROAD TO REACH 50 TO 60 MPG, HOWEVER I THINK IT IS ALREADY DOABLE, OH YES, BILLIONS……..
    BUT THEN HAS ANYBODY CONSIDER HOW MANY BILLIONS WE SPEND IN OUR MILITARY AROUND THE WORLD ON A WEEKLY BASIS??
    WHO KNOWS?

  5. C Moore

    Hey Larry I think you are referring to going virtual boating. Like in the Matrix or Inception. Uses no energy requires no materials. In the future we just get plugged into the grid & get feed streams of boating experiences without leaving the carbon foot prints.
    I thought the song went “dust in the wind” never found any answers in the wind they all turned out to be blow hards………………;-)
    Wake up now it’s time to get back to reality…..
    We spend billiuons because there are very bad people in the world that want to KILL US Larry…

  6. John

    One way to actually get real benefit from a hybrid setup in a boat is to do a plug in hybrid, similar to the Chevy Volt. That would allow efficient low speed cruising on electric power alone, with batteries recharged when plugged into shore power. For higher speed and/or when the battery pack is low you use the gas engine. The most basic existing example of this is an electric trolling motor with a bigger battery bank.
    A guy I know has replaced the diesel engine in his sail boat with an electric motor and a large battery bank, with a small generator for backup. I don’t think he’s used the generator yet, the batteries have been enough.

  7. Preben S. Kristensen

    Gerr stated:
    “Boats simply don’t receive the same benefits that cars do from hybrid systems. “Land vehicles generate savings when braking or coasting downhill,” Gerr explains. “Boats never get that benefit — at all”

    With a sailing boat, an electric motor/generator, an over-dimensioned CP propeller and a bigl battery bank (think ballast), you can create and store substantial amount of power by constantly “braking” the vessel, when propelled by the wind.
    Apart from the usual power losses, ie. propeller efficiency a.o., you are looking at a very efficient system with overall losses of 10-15%, mainly in the battery charging and minor losses in the electric motor/generator ~3-4%. Depending on the size of the battery bank, you could expect to be able to run the vessel at half hull speed for about 5-6 hours and the batteries. At anchor, you could run all the vessel’s systems – without having to run the generator – for 3-4 days.
    Naturally, you will have a diesel generator for emergencies, but it should be possible to run a boat like this for prolonged periods with absolutely minimal – if any – fossil fuel burning.

  8. CaptainA

    Hybrids do not make sense for planing hulls. They probably make sense for sailboats and may make sense for trawlers.

Leave a Reply

Your email address will not be published. Required fields are marked *

Comments are moderated and generally will be posted if they are on-topic and not abusive. For more information, please see our Comments Policy.