Improving On Perfection -The Next FPB

FPB Wicked 2

For years we’ve been wrestling with a way to improve on the FPB 83, Wind Horse. We’ve done smaller, as in the FPB 64: a very efficient, attractively priced, well-mannered yacht. And we’ve worked up a larger version in the guise of the FPB 115, about which we can get excited. But to improve on the Wind Horse combination of comfort, sea-kindliness, heavy weather ability, trans-ocean average speed, systems efficiency, and ease of handling for a couple has yet to happen.

Besides, this was the year we were supposed to get back to the serious business of field testing and research. Given the work load of the past year (cruising full-time while spending 60 hour weeks on the FPB program is not as easy as it might sound), we were due for some R and D and R and R.

So what would tempt us to change plans? We’ll start with systems.

Admittedly, we tend to be obsessive about systems efficiency. We enjoy quiet anchorages, and do not appreciate neighbors who incessantly run their engines or gensets to generate power.

The power consumption and replenishment cycle is directly related to efficiency, or lack thereof. Improved efficiency allows smaller gensets. Get it right, and you do not need a backup generator. Saving on the daily fuel burn significantly extends the vessel’s endurance. This impacts usable range –  how far and for how long you can venture forth. And to the extent that the boat represents shelter in a world unhinged, there is a significant improvement on how long you can survive without getting back into the system. This is also a kinder approach to the environment, and way more fun.

The work we did last year with the solar power generating system for Wind Horse really opened our eyes. What if we started from scratch with a clean sheet of paper (okay, a blank computer screen)? How many of those 320 watt, 19% efficient (at converting solar energy to electric power), solar panels could we fit? And think of the output robbing shading that might be eliminated.

Add in a new approach to air conditioning, coupled with a truly unique ventilation system (which we will address in the next few days), and it begins to look like it might be possible to sit at anchor, totally independent from fossil fuels while maintaining a wonderful level of ambiance. Even Al Gore might approve.

For more information on the FPB Series, e-mail Sue Grant: Sue.Grant@Berthon.Co.UK.

Posted by Steve Dashew  (January 25, 2012)

20 Responses to “Improving On Perfection -The Next FPB”

  1. Raj A Says:

    check out airdolphin wind generator. couple of those on aft along with the large solar array feeding 2000+ amp LiFeP04 pack, you will still be 1000lbs under the windhorse battery pack wieght.
    Cant wait to see the details.

  2. Anik Says:

    Steve, I’ve been a fan of your approach to rigorous, well-engineered design for years, and I’ve loved watching those characteristics manifest themselves in truly excellent cruising yachts. It looks like you are ahead of the curve again. You have our full attention.

  3. Matt Marsh Says:

    You had me at “no generator”. Anything you can do to avoid running one of those is good in my book.

    A well-designed solar array also offers a ridiculous level of redundancy. One bank of panels has dropped out? No worries, the others will keep things running until it’s convenient to fix it. Troubleshooting consists of flipping a few switches, sticking a voltmeter into several pairs of terminals, then swapping out whichever panel or controller is creating the fault. They’re far, far nicer to work on than generators are.

    The concern, of course, is still the capital cost. But on a boat the size and cost of an FPB, it’s going to be a fairly small percentage of the total, and not likely to turn away someone capable of affording such a vessel.

  4. Steve Dashew Says:

    Hi Matt:
    The capital cost of the solar installation will be much higher than a genset, and the payback, on diesel something like 10/15 years. But pragmatically, in a cruising yacht designed from scratch to be efficient (i.e not t he typical grid/generator dependent model), the benefits far outweigh the cost impact. This is before the emotional/ambiance/do good for the environment side of the equation.

  5. Patrick S Lasswell Says:

    The gating concerns for me would be the ease of replacement for the individual solar panels, the method of terminating the cable bundles, the methodology for reterminating the cables, and the process for replacing the wiring harness for the solar panels.

    Although I admit a strong bias against solar because it has been such a politicized energy method, the scope of the gathering methods also concerns me as a straight engineering challenge. There has to be so much advanced technology laid out across so much surface area continuously, that my experience as a testing guy tells me failure is going to be a matter of routine.

    Steve, there’s nobody I’d rather be a fugitive from the law of averages with than you. It will be interesting to see you make the best getaway boat so far.

  6. Steve Dashew Says:

    Hi Patrick:
    We have a simple system of modular installation which blind fastens the panels from the top. Panels will be wired individually, with multiple MPPT controllers, for redundancy and efficiency.

  7. Ed Says:

    “truly unique ventilation system” – let’s guess at forced air ventilation with heat exchanger.

  8. RDE Says:

    I’m sure you are aware that efficiencies of commercially available panels range from about 11% to as much as 21% depending upon the type of PV materials and the design characteristics. Far more important than the cost per panel in an application where space is constrained.

    You might consider adding two Duo-Gen water generators and two or three of the very best available wind generators to help grab electrons wherever they may be hiding!

  9. Rob Says:

    Solar and wind are both great. A water generator on a motor boat however is nothing more than the latest in a long line of perpetual motion machines. On a sailboat a water generator is a proxy wind generator as the boats motion through the water is gained from wind power. On a motor boat which burns diesel to move a water generator just creates drag, turning some of the fuels propulsive energy back into electricity. However there is already a much simpler more efficient way of making that conversion, it’s called a genset.

  10. Alain M Says:

    Everything who gives us more time off the grid is a benefit… Tankage and fuel efficiency to be able to do longer passage distance and stay of the grid again… Boat insulation and double glass windows to have better comfort, with Air in/out system with heat (/cold) exchanger to save more energy from already most efficient and optimized heating system and air conditioning system… Solar panel and wind generator to catch energy that are for free and extend the time at anchorage on batteries without the genset working… And all works best if all systems are from beginning right optimized about energy saving and integrated in each other…
    Water generators, if carefully designed, are nice energy maker for sail boat, but are useless in case of motor boat, unless you regularly take anchor in rivers or strong current place…
    And Steve you said true that if you start one design really from scratch, and include all this before mentioned feature, it will be really interesting and it could certainly be more efficient. As adding any tools or machine or material is every time one headache and integration problem if not think about from the time of the original design…
    Really waiting about what you have in mind Steve…

  11. Larry Says:

    I’ve been looking at vacuum solar tubes. Apparently they can boil water in no time. The info says that the are 90 some percent efficient. I would have to think they have a minimal carbon footprint. Maybe a steam driven generator, perhaps thermoelectric generator…….

    I have been following you for a couple years.


  12. Steve Dashew Says:

    Hi Larry:
    More info on the vacuum solar tubes to which you refer would be welcome. Thinking in terms of heating water and air conditioning.

  13. Sebastian Says:


    These evacuated tube systems are becoming quite popular for domestic hot water in Australia now.

    This site gives you a very brief run down, but the general principle is that because the sun strikes a tube rather than a flat surface, it is always perpendicular which greatly improves the effieciency.

    Looking forward to more info about your new FPB.


  14. Steve Dashew Says:

    Looks fascinating, Sebastian:
    Do you or anyone else have first hand experience with these. And is their a source in the US?

  15. Skip Says:

    Vacuum tube solar water heaters are used all over the world. They work in all environments as the vacuum isolates the heated water from the outside and they are much lighter than the old flat plate stuff from the sixties. I’ve seen them in Colorado, Vermont, Virginia and they are getting alot of use in China. Heck, they sell them on Amazon. I’m sure you could even get a tax credit if you install on your “second home” Windhorse.

  16. Larry Says:

    Here is an interesting website.
    Air conditioning is mentioned at the website. I’m not sure why. (or how)
    Be SURE to look at their radiant floor heating. This is the most comfortable heat you can experience!!!!!!!!!! Tubing under an aluminum deck would transfer heat perfectly.
    Heating hot water could be passive or you could move water with a low voltage pump powered by a pv module.
    Heating fuel in cold climate an issue? It’s nice on injectors in the North.

    I have no first hand experience on these ideas, except the in-floor heating. Here is a website for that.

  17. Larry Says:

    Solar Air Conditioning link

    It looks like they are using solar vacuum tubes to heat the gas so it will condense at a higher temperature. This reduces the workload on the compressor requiring less Watts.
    Normal refrigeration requires high pressure from compressor = more Wattage.

  18. Skip Says:


    Try this article, the link says it all.;txt

  19. Alain M Says:

    Hi ,
    Sorry to say, but nothing really new about floor heating…
    1996, one family house, underground floor and car garage, with ground and upper floor at about 220 sq meter . The ground floor in concrete, insulation with the upper side like eggs box shape (sorry, don’t know the exact name in English) with holding system for the tubing, PEX tubing, concrete and ceramic flooring. Upper floor in concrete, insulation, PEX tubing, special light concrete, and direct contact ‘wood’ laminate floor… It work perfect with a high efficiency propane boiler system, with mid season or high sunny day in winter using one solar heating system instead of the boiler. I remember one winter with 3 sunny days with day temp at -18 Celsius and night at -22 to 25 Celsius without any propane use, but for this you need the whole system to be well built and efficient, including complete and perfect installation, regulation and insulation, that means hunting down every cold bridge (who is most easily done by outside insulation or in between wall insulation, by inside insulation it is near a crazy job to do it perfectly)…
    But applied to boat, only inside insulation is possible, more tough, and the floor heating is more difficult to do, cause of the poor quantity of surface floor available, it has to be back up with passive radiator (who are quiet) or dynamic airflow radiator (who are noisy, unless using big size and low speed ventilator)…

    Speaking of the vacuum tube as water heating, true, they are much more efficient that the old system I used before. For one off grid installation I would sure thinking about this tube coupled with one couple of Stirling generator. One for use the hot water to produce electricity (on one more efficient way that solar panel, as moment or light shading have less impact) and the house heating as beside production. Another for use in summer in inverse mode, using hot water to produce cold for climates the house and even maybe fridge and deep freezer if right design…
    But that one hell of a installation that I see good on one house, but the size made it difficult to integrate in one boat,,,

    I use a Stirling generator, 8 to 10 KW heating and 1KW/h electricity, originally AC model fire by propane, now fire by diesel on boat…Installation need to be good, specially about the condense water from exhaust, it is where most people have problem… Hot boat, hot water, 1KW or 850W (in DC version) electricity, quiet running, around 0.5 liter diesel per hour…

    Links are mostly about DC Power, the first and last one are about AC power…
    But integration of solar vacuum tube on one boat…???…
    But maybe Steve will surprise us???


  20. Larry Says:

    Great article Skip!
    Heat is energy. Wasted heat is wasted energy. They’re “correcting” the economics.