Alternative Propulsion Systems

[George Wade]

As solar —> electric; Wind —> electric; Hybrid diesel electric appear to be the most practical systems: we find other great ideas sidelined, perhaps. This thread is to keep those experimental; possibly emerging technologies alive.

Here's one. The title may be grandiose? Certainly interesting; hope the URL makes it.

View topic - I have a dream...power cars/boats with compressed air! : Cruisers Forum : Latitudes & Attitudes Magazine

Keeping the system in mind is vital. Trapping and directing the energy; storing it; using it when needed; maintaining the system and getting parts that break or making them by hand anchored somewhere remote and otherwise peaceful...

[James S]

Compressed air as a power source is interesting...I've had an idea for generating compressed air on board for some time but it still hasn’t migrated to the top of the list.
Cool stuff, thanks for the link.

[Little Otter]

Didn't the mythbusters do some thing like that that would work if you could keep compressed air going.

[Nordic cat]

Compressors are rather inefficient at converting any power source compared to even an IC engine. The higher the pressure the lower the efficiency, piston compressors especially. That is why all compressors need cooling, just like your fridge at home.

As a means of propulsion on a boat for cruising it's a joke!

Alan

[George Wade]

By the time oil has been explored for; drilled for; transported to refineries; cracked; fractionated by distillation: what percentage do you suppose has been burnt to achieve that end. When you add in the percentage of oil taken to build and heat the oil industries workers' housing; cook their meals; drive their kids to school etc. The percentage sold off to provide executive salaries and bonuses; to pay lobbyists and their friends in power. To pay for wars that keep oil fields in friendly hands.

Just how much of an efficiency joke would that be in total — if looked at honestly and openly ? And I'm writing that in a reasonable tone of voice, as far as I can tell. Certainly those figures must be calculated and obfuscated by economists; they must be available reasonably easily. Several people on this forum may well have paid for their yachts by researching and knowing that invaluable wisdom.

Also: if we joke about it long enough, someone will come up with an improvement. Here's one — when the compressed air decompresses to run the motor it will cool. that cool exhaust can be diverted over one end of a Stirling engine to provide extra rotational energy. Enough improvements and we shall have a viable system. When the air is compressed to store it, it will warm up. That heat can be dissipated by running it over the opposite end of the same Stirling engine: it will compress better when cooled, too. Now the joke is not looking so bad.

[George Wade]

Compressing air by utilising wave energy while passage making or at anchor:—

Mono-hulls could have a swing keel, damped by double acting, robust hydraulic rams. The damping could ease the motion of the yacht while extracting useful power from wave action. Some of that could feed getto blasters and fish attractors; some could be stored as compressed air. A good used Volvo 60 would make an interesting test bed; it has a swing keel already.

Catamarans could be designed to look like trimarans: with central accommodation that moves with wave action; carefully damped with hydraulic rams and the energy extracted used for a variety of purposes, including compressing air. It could be used to electrolyse water, too: compressing the hydrogen and oxygen separately.

As the gasses are used they could run through motors for one source of power. The oxygen would be great for hyperbaric treatment of hangovers and other disabilities. The hydrogen for newer designs of fuel cells. When several systems can use the stored gasses it becomes more useful. I do just hope you don't think I'm joking...

[James S]

I dont think your Joking.

[George Wade]

Originally Posted by James S

I don't think you're Joking.

Thanks James. From your perspective in Yemen you wouldn't think it a joke, more than likely. Interesting that it is Eastern countries that are doing the greatest development in solar and wind power; while the USA makes the greatest noise.

But seriously: humour is the most human characteristic. It is a great creative engine to be able to blow off hot, compressed air. So I agree with Alan that compressed air energy storage on a cruising yacht is a joke.

[James S]

Just an interesting note about unconventional propulsion thinking ...a friend recently sent me a Popular Science article from 1933 on a steam powered airplane.
A 180lb steam engine developing 150 HP in 1933....I thought that was pretty impressive.
Its an excellent article with some good tech details....and oh yeh...the engine was said to be very quiet...spectators on the ground could hear the pilot say "hello as he flew past!

[George Wade]

Originally Posted by James S

Just an interesting note about unconventional propulsion thinking... a Popular Science article from 1933.....
A 180lb steam engine developing 150 HP in 1933.... the engine was said to be very quiet...spectators on the ground could hear the pilot say "Hello" as he flew past!

Didn't those 180 lb steam engines need a 1,800 lb condenser; am I just repeating old prejudices ? Though it does make us rethink traditional practices.

Anyway: I should save up and try my own wild ideas on a SeaWind 24; better yet on a 5 meter beach cat. One would be a wave driven float on an 'A or Y' frame. The motion driving an air compressor and data logging.

The same experiments at full size on a 40 ~ 60 ft cruising boat would be much too costly: which would stifle most practical creativity before it would even get started. The sun is now shining here, so I don't expect many replies till October.

[James S]

Nope...PM me if you want the artical...its pretty cool.

[George Wade]

Originally Posted by James S

Nope...PM me if you want the article...its pretty cool.

Thanks for the offer. I'm guessing that PM is personal message...

[James S]

Sent...good luck

[newt]

Your thread is interesting, but I feel you are going all over to look for energy- When there is plenty right at your feet. Harness the power of the waves and the currents and you should have enough to power whatever you want on your sailboat. Solar/wind these are a step in the right direction. But the sea has incredible energy. We just have to figure out how to use it.

[George Wade]

Originally Posted by newt

Your thread is interesting... Harness the power of the waves and the currents and you should have enough to power whatever you want on your sailboat. Solar/wind these are a step in the right direction. But the sea has incredible energy. We just have to figure out how to use it.

Absolutely RIGHT Newt. Waves can be harnessed while sailing; currents while anchored, except when they are going our way when we just ride them. Wind power is traditional sailing, kite sailing or wind turbine to propeller sailing.