How About No More Electric Boats?

Discussion in 'Boat Design' started by DogCavalry, Mar 18, 2021.

  1. mitchgrunes
    Joined: Jul 2020
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    mitchgrunes Junior Member

    Hey guys!

    In reservoirs that feed urban water supplies, electric boats add much less harmful pollution to the water, and gas powered boats are often forbidden in such places. For the most part electrics make less acoustic noise too. In some cities, smog is a huge health problem. So electrics definitely have their place.

    If you don't want to waste energy and CO2 production on recreational boats, don't build recreational boats. But I don't think we are at the point we need to do that. I have noticed that some of the people who talk the talk about green energy own large houses, that waste a lot more energy than most boats, or even RVs. Last I checked, it was still the case that homes, buildings, and their construction, are the dominant form of energy use, and lead to a very large fraction of mining for raw materials. If you want to be green, reducing home and building size should be your first priority.

    It really isn't possible to produce or store large amounts of energy in a completely "green" manner. One way or another, you are changing the environment.

    Could you recycle the Lithium in lithium batteries?

    Sodium ion based batteries are a possible alternative to Lithium ion based batteries, and are under development. They are so far somewhat heavier, but are expected to be much cheaper. And sodium is a much more plentiful material, that requires less intensive mining, and less harmful disposal.

    Fuel cells mostly use a catalyst material which is very uncommon (e.g., platinum, or palladium), and requires a lot of environmentally undesirable mining to obtain. Also, they need to be handled very carefully - it is an explosively dangerous technology, based primarily on hydrogen gas produced from other fossil fuels. People have died working with fuel cells. Nothing based on hydrogen gas is completely ideal in the hands of your average drunk yahoo out for a beer enhanced fishing trip.

    Lead-acid batteries have its own environmental and production related health issues. Also, it can release toxic chlorine gas if the acid hits salt water.

    Someone I knew, Talbot Chubb, received a U.S. government civilian service award for developing a (thermal) energy storage technology based on molten salts. (They have a high specific heat.) It's an obviously doable technology, that requires no new science. But I saw him talk a potential investor out of investing in the idea, because Talbot tried to tell him that cold fusion (that he believed would work - he and his nephew, Scott Chubb, had developed a theory for a hypothetical cold fusion reaction, in which the deuterons would react after entering an ion band state in deuterium packed palladium or silver, and the resultant alpha particles - i.e., He 4 nuclei - would remain in their own band state long enough to pass the resultant energy to the crystal grain, in the form of phonons and eventually heat, rather than producing a lot of neutron radiation, because the atomic spacing in palladium or silver is too small to fit He 4 in the interstices; Paul Dirac had another quantum physics based theory for how cold fusion could work.) would replace everything. It hasn't. Perhaps molten salt heat storage would have been practical, and could have stored energy for some of our cars and boats, plus it might be more efficient to generate solar heat than solar electricity. But as far as I know, no one demonstrably succeeded in making cold fusion work, unless you go in for conspiracy theories. Sigh.

    Hot fusion is starting to produce positive results, and may be usable in a few decades. But it will never be completely clean.

    Those who have an interest in whitewater boating don't always like hydroelectric plants, because you tend to replace rapids with standing water. And if you think they don't have an environmental impact, ask yourself what the environmental impact is of flooding (in some cases) a few hundred square miles of land and stream with standing water. Or of replacing warm-water outflow with cold water bottom-of-dam outflow. Or of replacing running aerated water with slow flowing water. Or of the earthquakes that many large hydroelectric plants produce during and after droughts, when water levels change, or when they fill the first time. (As hard as this is to believe, just a few hundred square miles of land flooded with fairly deep water weighs enough to destabilize some geological faults, maybe even enough to produce new ones.) Or of someone bombing a big hydroelectric dam just upriver of a major city. (Big dams have to be very strong. Still...)

    Likewise, tidal power (E.g., you could flood a series of reservoirs separated by hydroelectric plants, at high tide, eventually letting the water back into the sea at low tide.) has tremendous potential power capacity. I admit I love that idea - I just came up with it, though I'm sure I can't be the first one. I might be wrong, but would be willing to bet it could yield orders of magnitude more energy than offshore wind power. (Could some of the people on this forum who are real engineers give a reason why it would be impractical?) But you can't take energy out of moving water, or flood inland reservoirs, without having environmental side effects.

    A lot of modern energy is generated by burning natural gas. It has the advantage of creating less CO2 / kilowatt hour than burning coal. But the natural gas is most efficiently produced by using fracking. Fracking - and the deep well high pressure burial of the probably extremely toxic and/or carcinogenic fracking compounds - has the potential to eventually release those toxic materials, as well as materials in the fracked rock, into the surface water supply - perhaps immediately, perhaps centuries or millennia in the future. The companies that frack generally won't even say what chemicals are being used. Also, in some areas, the fracking, or deep well burial, has created earthquakes, according to a USGS study. I even talked to someone whose relative's tap water was flammable because of fracking. :eek: So natural gas isn't completely green.

    My conclusion: if we want cheap abundant energy, and most of us do, we have to accept some bad things.

    The answer to all this is simple! Use smaller homes and buildings (the most important step, and the overwhelmingly most important step for a concerned environmentalist to work on), and make all recreational boaters use kayaks. :) Less material, and therefore less pollution is created making a small home or building, or kayak, than making a large home or building, or yacht. Less energy is consumed taking the kayak to the water than a yacht. When there is no wind, kayaks use less energy to use. But I imagine a few of you, in this boat design forum, would disagree that this is a universally desirable solution.

    BTW, raising the world sea level a few inches or even a foot won't end the earth. Some people living too close to sea level will have to relocate to other areas, possibly including previously cold climates, like northern Canada, Siberia and Antarctica. Of course, people in some countries can't, because there is no place to go, and other countries won't let them in. But that is a political problem, that might have political solutions. Also, the Dutch have used dikes for about a millennia, and others have used seawalls and breakwaters. (If only we had a "force field" that could stop storms, including the storm surges and waves they generate. Alas.)

    I have sufficient faith in the human race to believe we will find acceptable solutions to limit global warming, and its effects. I'm not saying global warming isn't a problem. But it shouldn't stop us from using small craft. That's almost in the noise level of environmental problems.

    Besides, don't you want to test out the theories about the global warming solution envisioned in Snowpiercer? :)
     
    Last edited: Mar 31, 2021
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  2. hoytedow
    Joined: Sep 2009
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    hoytedow wood butcher

    So everything we do has an impact upon the environment. Beavers likewise.
    We could go back to oars but there are only so many trees if you can get past the tree huggers. Better to hug an oar. Not many oar houses left.
     
  3. Squidly-Diddly
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    Squidly-Diddly Senior Member

    "Boating" mag this month has story about "good bye to (ICE) motors on boats"

    will link or post later
     
  4. gonzo
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    gonzo Senior Member

    Firstly, if there was no profit governments and big business wouldn't have any interest in it. An engineer hired by a company would make the economic analysis to provide the company or government entity with tangible and verifiable values of a project.
     
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  5. Will Gilmore
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    Will Gilmore Senior Member

    They are called actuaries. An analysis of the efficiencies, checks and balances, profitability in a dynamic market, a changing corporation and even a litigous environment requires the mind of a mathematician and an engineer. There is a special branch of Mathematics just for those type of professionals. Their fundamental job is to answer the question, "is it worth it?"
     
  6. Dejay
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    Dejay Senior Newbie

    In modern neoliberal economic theory that leaves out tangible and verifiable effects that are externalities like quality of life, health effects, cost of pollution and aesthetic value of the environment. Or effects that cannot be evaluated because they are too complex for the scope. Or solutions that would require planned restructuring of whole economic sectors.

    Things that aren't part of an economic analysis but in theory should be - for answering questions like "should we build more electric boats".

    In practice we can't. Hence the pickle.
     
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  7. mitchgrunes
    Joined: Jul 2020
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    mitchgrunes Junior Member

    Let me see if I understand the basic idea. If you charge a battery to power an electric boat motor, you loose some of the power from a fossil fuel power plant in the electric lines, and some of it in the battery.

    But on the other hand, small internal combustion engines, such are present on small gasoline (petrol for Brits) powered boats, probably operate at very low efficiency, whereas the large turbines in power plants are much higher. So - is it possible you are usually more efficient burning those fossil fuels in a big central power plant, and charging up the battery in your boat, uses less total energy than burning those fossil fuels in the little boat motors?

    Also, it is sometimes practical to burn natural gas in a central power plant, but not (safely) in a little boat motor. And natural gas does release a lot less CO2 than gasoline / unit of energy.

    Again, river and tide based hydroelectric plants (using effectively "renewable" energy, since the sun exhausts its fuel whether or not we use it) are possible in a central power plant, but are impractical for small craft.

    But it would be fun to try to power a small boat using solar thermal heat. Absorb sunlight, convert to heat, which runs a small heat engine, with a mechanical linkage to the propeller - or you heat air, and it expands to create a rocket-like exhaust. No electricity involved. In theory, you get about 1 kw/square meter of solar energy. 1 kw=1.34 hp, far more than you need to power a small craft, like a canoe, for recreational trips, even more if you can store the heat. Somewhat larger craft could use more than 1 square meter. Of course there are losses of heat, losses in the turbine, and losses in the linkages (the latter applies to almost any marine motor). And it wouldn't be all weather. Maybe it would be fun to try, though I lack the knowledge.
     
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  8. Dejay
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    Dejay Senior Newbie

    That's actually an interesting idea. There are "photovoltaic thermal hybrid solar collector" that produce electricity and heat at the same time. They can produce 2 units of thermal energy for each 1 unit of electrical energy.
    You could pump some kind of refrigerant through them with a low enough boiling point to drive a turbine, then gets circulated to radiators in the hull to be cooled and liquefied again by the water.

    I'm guessing there is probably a reason why this isn't done though.
     
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  9. mitchgrunes
    Joined: Jul 2020
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    mitchgrunes Junior Member

    Thanks! Most solar power projects have economic issues due to low power density.

    There is no need for the solar heat collector to be on the boat. Perhaps Dr. Chubb's molten salt heat storage idea could be used to transport heat to the boat from your home. Then you can use concave mirrors or lenses to concentrate the heat.

    There was at one point some work on "solar heat motors". But you can buy solar cells and electric motors off the shelf.

    There is a well proven class of external solar heat motor powered craft. If you want to look them up, the technical term for such a craft is "sail boat". :)
     
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  10. Will Gilmore
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    Will Gilmore Senior Member

    I always wondered how using old garage door springs to store energy for a boat would work. If you could laminate two different materials together in a coil spring so it was sensitive to temperature changes, like a leaf spring thermometer, could that be used to tighten the garage door springs as the temperature changed? When it was cool, a cover could open, exposing it to the Sun, when it was hot, the cover would close, shading it until it cooled down. As the spring moves it drives a gear that winds the spring which drives the propeller.
     
    Last edited: Apr 5, 2021
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  11. gonzo
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    gonzo Senior Member

    I suppose if a cruising range of half a mile was sufficient it could be done.
     
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  12. Dejay
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    Dejay Senior Newbie

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  13. hoytedow
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    hoytedow wood butcher

    You could also power a boat with a recoil starter rope but should you?
     
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  14. portacruise
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    portacruise Senior Member

    Ha, that's funny! But it may come to that or something derived from that once fossil fuels are gone for some circumstances ...
    Besides hpb might be least likely to attract guvment regs like taxing, registration, policing, inspections, etc. compared to other forms of energy propulsion, which might be a plus?

    https://www.axamarine.com/hand-propeller-outboard

    Half a mile thing, at present?
     

  15. Will Gilmore
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    Will Gilmore Senior Member

    Gonzo was being generous.

    I don't know how to calculate it, but a garage door spring can hold up about 200 lbs with an extention of about 3-1/2 feet. Hook's law says the force is directly related to distance so if you could extend the same spring to seven feet, that's 400lbs of force and 100 lbs of force at 1-3/4 feet of extension. Adding more springs would, of course multiply that force.

    So, how much force is necessary to get a propeller of, say, 12" diameter, to spin 100 times with 100 lbs of thrust? Then calculate a spring with a 4' extention (about 225lbs of force maximum). How many springs would it take to drive this ideal boat at 4 knots for eight minutes?
     
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