Alternative / Innovative Out of the box energy storage?

[jwcolby54]

Originally Posted by Rapanui

However, while the issues outlined above make it impractical for propulsion, it may be practical to make hydrogen for cooking pupose if you have excess electrical capacity from solar, particularly in places where it is difficult to refill or exchange lpg bottles. Playing devils advocate though, it would seem easier and more efficient to use excess electricty for cooking.

Not to mention that the end result of burning hydrogen is water so the moisture inside of the boat would skyrocket after every meal.

[Philip St1]

Note: burning anything produces water vapor (Re: hydro-carbons), but hey---you got to eat.

A solar oven would be better than using "excess" solar power since the efficiency of solar for electricity is no better than 22% and the efficiency of solar heat collection is in the 80 to 90% range. Solar ovens take longer to cook, but the solar panel takes a long time to collect its power, too (and you have to store it up). Ad it you 'cook' at 130-150 degrees, you don't have to aim them.

I have yet to read about anyone on a boat having "excess" solar power. The shading by the mast and boom usually minimize what you can collect (I have 16 small panels for that reason---shade on one just cuts out 25 watts, not 100).

Another way to 'cook' is to boil water on the stove and pour it into a thermos with your ingredients to 'cook' for the required time (which will be longer, but you can do pasta, rice, even beans this way). "Sailing the Farm" has a lot of good ideas on minimizing energy usage. Easy plans for solar still for fresh water, too (and it works for distilling spirits, too).

[Djarraluda]

If we look at the sun as the energy source, we can either gather it as heat, or convert to solar PV electricity. PV is straightforward, some sort of battery bank and keep reading the journals for the latest and greatest. Laptops tend to use LiIon, which have a nasty habit of overheating, so banks of these have to be treated with caution. Pumped storage and similar probably not the best on a boat, so.....watch this space for the next great development.

Heat, on the other hand, we store as a big block of energy, such as the clarifier for our hot water. In more commercial arrangements, we use a Phase Change Material to store the heat (or coolth) - think of the energy to create ice, with no temp change, we get massive energy store from solid to liquid. Same for steam at the liquid to gas phase. We have various salts (eutectic fluids) that we use to make that phase change at the right temp for our application. As an extreme, we use sodium to cool nuclear reactors.
Re the Hydrogen debate, for a moment I thought you were looking for perpetual motion - power to create hydrogen, to then use to create power. Sadly, there are losses involved and the original energy source vs the final product may be more involved than we find practical at present.
So once again, we are at the Horses for Courses stage. We have the energy storage technology available (for a price) but what do you want to use it for?

[hamburking]

The rocking motion of the boat could be used to generate electricity. The output would be fairly small, and the device fairly large. But that didn't stop solar panels!

[Serapium]

Interesting thought, hamburking. I had also been toying with the idea of setting up some kind of smaller hydrogenerator to deploy over the side when at anchor in a place where there is mild current. You wouldn't be able to produce tons of energy, but I bet you could come up with enough to charge a cell phone or power a bluetooth speaker.

[valhalla360]

What about a freezer with two thermostats. The first ensures the freezer stays below some upper limit. The other driven by excess energy, drives the freezer down as cold as possible. That way when the exess energy goes away it's a long time before the freezer kicks back on.

[transmitterdan]

Originally Posted by oleman

I am relatively certain when Joshua Slocum made his voyages he was not concerned about surplus energy storage.

Actually he was. He had to forage for stove wood from time to time.

[a64pilot]

I've toyed with the idea of using Prius batteries from the junkyard, or other Hybrids, just believe the Toyota battery is more widely available
I'm sure they aren't ideal, but the price is right. I believe they are wired in series to deliver very high voltage so you would likely have to re-wire them, and I feel they aren't the ideal deep cycle battery, I think a Prius manages them between 40 and 80% SOC, but if they can be had as cheaply as I have heard, then you can accept less than ideal?


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[Serapium]

A64, I've not heard of that... Very interesting thought. How cheap is cheap?

[Serapium]

Hmmmm. Maybe not the best of ideas

Found on an alternative energy site : "Bundling these battery banks is not recommended, for a few reasons. The battery pack in the Prius (or any of the other hybrids) does not have the capacity for much range by itself. Even at low speeds in pure-electric mode, the Prius has only about 2 miles of range before the gas engine starts up to recharge the pack. So you would need a lot of packs to get any decent range.

Also, these batteries are not intended to be discharged very deeply. They were specifically designed to work with a gas engine frequently topping them off. In a pure electric vehicle, you need batteries that can tolerate being deeply discharged before getting recharged.

You would also need the battery management system that is part of the Prius’s computer brain. While these battery packs are perfectly safe in the Prius, if they are installed or managed improperly, they can catch fire, which some tinkerers have already had the misfortune to experience."

[a64pilot]

Serapim is essentially correct, but how many battery technologies will give you much more than 40% SOC?
Older Prii's are all Ni-Mh, which is of course not the best technology, but was picked as it was relatively safe, but any large bank, even flooded lead acid ought to be managed, there is a huge amount of power there.

Cost, I don't know, just the opposite of most nay-sayers, the battery packs on these cars seem to out last the cars, are enormously well protected and due to the normal loss rate of any automobile, apparently there are many good packs that are un-claimed as there is essentially not much demand, I believe their value is essentially scrap, but I have not priced them, it was just sort of an idea, I guess really for those that live off the grid.
Basically if the cost is low enough, you can accept less than ideal performance.



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[mramoo]

The Prius batteries are 7.2V at 6.4 AH, on E-Bay they are going for anything from $25 and up.

[a64pilot]

Originally Posted by mramoo

The Prius batteries are 7.2V at 6.4 AH, on E-Bay they are going for anything from $25 and up.

That may be the little 12V battery?
The car has a regular lead acid battery just as any car does, near as I can figure this battery is only used to "boot" the cars computer, or possibly an emergency bus?
What I was referring to is sometimes called the "traction battery".


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[mramoo]

This is what they are selling on ebay, it doen not look like a small 12v battery

[Serapium]

Hmmm. A little bit of searching later and I'm wondering if a person could rewire a Nissan Leaf battery or put it through some kind of voltage changer and make it useful. The standard battery is 24,000 Watt Hours at 360 Volts. If I'm doing my math correctly and assuming little loss through a voltage conversion that equates to roughly 2000 Amp Hours at 12V.

A brand new Leaf battery can be had for $5,500. On a cost-per-amp-hour measurement that puts it well inside the cost of AGM batteries.

I wonder how much a used one is.....