the single most important question for any alternate-fuel ships?

greetings.

i've been eagerly reading up on this forum for a few weeks now, and particularly the alternate fuel posts. but one question seems to never be asked, or at least i'm missing it. perhaps it's something i should already know but don't due to a total lack of boating experience... but here it goes : what would be a reasonable safe minimum distance you should be able to sail on energy stores, and what would be a reasonable safe maximum time required to have your boat sit and refill those stores once exhausted?

it seems that the single biggest draw-back with alternate fuels is that you're never going to match the energy potential of old-school fossil fuels. pound for pound. similarly, if you're running on anything exotic you better be self-producing or you'll be limited in wherever you can get more of it. since it seems like we're decades off from solar panels/batteries efficient enough to fit enough of either on a boat to directly run an engine AND charge the battery bank there is always going to be a question of "how far can i go before i need to park and recharge".

so then... what is a viable distance you can run between needing to stop and let those batteries, or hydrogen stores, or unicorns recharge from whatever alternate source you've got? and how long can you sit around doing so before you should feel squeamish about being unable to flee from an unexpected typhoon/political 'issue'?

 

For commercial applications there needs to be enough fuel to do the trips in one go with a safety margin surplus. The refuelling time must be no longer than the boat will be in the harbour anyways unloading and reloading, which is a timescale of hours.

For something like hydrogen or methane there is no reason why it can't be competitive with current standard fuels.

The only issue is the lack of port infrastructure supporting these 'new' fuels.

It is a real shame that people haven't had the foresight to begin the changes a while ago already and instead wait until the price of the last remaining drops of fossil fuel reach such astronomical prices that there is no longer any option. Therefore the transition is bound to be as all things done in haste, fraught with problems and tensions.

Battery technology is no where near the point it needs to be at to be practical on commercial ships. On smaller yachts it is a different matter, as the scaling laws favor smallness when it comes to solar electric.

 

Solar is fairly impractical as a power source, and I think a better use of the sun at sea would be using a fresnel lens to distill sea water into fresh. This would greatly reduce the amount of needed water weight, and could free up room for batteries to be charged using wind turbines. Seems it's a lot more practical to use sails primarily, and store electrical power from wind turbines as a back up.

A lack of technology in energy storage is not a problem, as some would have us believe, the problem is cost of materials and availability. Hydrogen is light and powerful, but isolating it from all oxygen and compressing it into tanks is not so simple, and it requires carbon fiber (sold at an absurdly inflated price) tanks vs regular steel ones. Hydrogen is not very dense, so althought light, it requires a lot of room.

Superconductor electrical storage is one underdiscussed possible option that could have an efficiency of power/weight that would leave batteries in the dust.

Give me a few million dollars budget, and the sky is the limit, but without that initial money, there isn't much you can do. Unfortunately most millionaires these days seem more interested in showing off in boat with six 300hp outboards. On the other hand, cloth is cheap, and wind is free, right? If it's a matter of waiting for the last drops of oil to run out, we're going to be waiting about a hundred years, if it even happens then. There is still a lot in the ground.

I love the idea of being able to just cast away from land, and live autonomously, going wherever I want indefinately, but at the moment it seems that the power struggle is a losing battle for the common man. It seems every so-called solution that is trumped up in the news, like the solar-electrical 'paint' I was hearing so much about, just quietly disappears. No doubt the military is snapping up the output, just as they do with carbon fiber.

Let's face facts, the authority figures in this world can only hold power so long as they, well, hold power. If energy was a free resource available to everyone, we could produce our own food in our own homes if we wanted, travel as much as we pleased and there wouldn't be much incentive to work in a corporate structure for a fraction of what our time is worth.

 

<<<<<<<If it's a matter of waiting for the last drops of oil to run out, we're going to be waiting about a hundred years, if it even happens then. There is still a lot in the ground.>>>>>>

Please inform yourself;


http://en.wikipedia.org/wiki/Hubbert_peak_theory

http://www.youtube.com/watch?v=F-QA2rkpBSY&feature=PlayList&p=6A1FD147A45EF50D&index=0&playnext=1

http://www.theoildrum.com/node/3720

We're in for some big changes coming up real soon.

Hydrogen does not need carbon fibre tanks. There are other cheaper methods.

 

Well, I already know how to make hydrogen, so feel free to explain the cheaper methods of storage. As for exponential growth of the population, if many problems other than a potential oil shortage aren't solved quickly, I suspect it won't be a concern anymore.

 

Also, I could add, the country I live in doesn't even manage to replace its own population. We are only growing as a nation because of our open door immigration policy. The solution is a return to responsible nationalism, not an authoritarian world government.

We should be looking to space, and allowing more people to participate in technological development instead of keeping so much of it hidden away.

 

Well that was way too fast for you to have watched the whole thing . He talks about a lot of subjects , including peak oil, not just population growth, although the two are intimately linked.

Here is a video to entertain you for now, its a bit simple but it shows a neat hydrogen storage system.

http://www.youtube.com/watch?v=BX2RxlXCZKA

 

Post #6 - i agree

 

Don't have time to watch the whole thing right now, I have to get to work. BTW, I didn't see the link to the hydrogen storage method, I'd like to see it though.

 

Well....your minimum and maximum will depend totally on use....required range varies wildly with the type of boat and its intended voyage.

I have a cruising range of about 12 hours in my outboard skiff, sometime in that cruising period I need to buy gas. Steve Dashew on Windhorse thinks a range of 3000-6000 miles between fueling stops is adequate.

There are thousands (millions?) of outboard skiffs used for fishing on lakes and rivers that need a cruising endurance of perhaps 1 hour. They could easily be using alternate (probably electric) propulsion.

You must define the intended voyage pretty closely before starting to worry about the energy requirements. After defining the intended voyage my second question is what is the payload? People, accommodation, cargo, etc? After that comes time period (speed). Only with these inputs can we reach any useful conclusion on energy use.

 

Well considering the mention of typhoons and political situations, I would assume the range and duration is intended to be as much as possible. . . I generally don't worry about such things on a 5 hour fishing trip!

 

hummmm.......range, speed, and payload are "as much as possible". That's a useful figure......

What's the budget....unlimited as well?

 

CNG compressed natural gas in the USA will become quite popular for trucks, car and boats once they settle on a design for ANG absorbed natural gas tanks that don't require the very high pressures and allow you to carry volumn.

 

@tad, and others. i was mostly referring to a ship you would use as a long-distance cruiser and liveaboard. something that doesn't have to be quick by any measure (except being able to be safe) but capable of going wherever you wanted.

of course, my question shouldn't mean that "wherever" need be in a single non-stop line. just more generally; if planning on a long-distance cruiser... what is a good minimum range to be able to get to? to facilitate traveling about the world?

 

For water travel, the solution is obvious, and it's not new.
Sail.