Economic analysis of aluminum electrolysis

Fifth of this series.

This may not be very economical.

Now, let's look at where we are in this analysis.  We've got the technical details ironed out, for the most part.  It all looks feasible from that viewpoint.  So, how much does this cost?

It would have to be better than electrolyzing water, or otherwise you are going through a lot of trouble to accomplish a task that could be simplified.  It seems that some time ago, I read that it took about 43 kwh of electricity to produce 1 kg of hydrogen.  This sort of jibes with the post here that hydrogen production and subsequent use is about 60% efficient.  Now, if it takes about 20 kwh to drive at highway speed for one hour and it takes 1 kg of hydrogen to do it, that means that efficiency wise, you've got 20/43 equal 46.5% efficient.  If you square those terms, you get about 21%.  You'd square it assuming it is the same efficiency going from water to hydrogen as it is from going to hydrogen back to water.  If you square .6, you get 36%.  Quite a range.

I'm not sure what the accurate number is, but it is rather high for electrolysis of water.  For comparison purposes, aluminum had better do a better job than this, or we are better off electrolyzing water.

Now, if you were to ship your ore, which was obtained from the process described in the earlier posts in this series, you might get an exchange that will yield a cost of 13 bucks per kilogram of hydrogen.  Not very good.

Here's how I figured that:
price of aluminum equals $0.91 lb, or about $2.00 kg
price of aluminum ore $500 ton, or about $0.55 kg

Since it takes about 9 kg of aluminum to produce 1 kg of hydrogen, multiply the difference (2.00-0.55) times 9, which gives $13.05 kg hydrogen from the necessary aluminum it would take to do the electrolysis.

You'd be shipping the ore to the processor who would give you back aluminum.  The difference is the cost of the aluminum minus the cost of the ore ( not counting shipping costs).

What about skipping the middle man and doing it all on site?  Even if you cut the costs in half, you still have to pay more than just electrolyzing water.  For example of water electrolysis, if you pay 10 cents per kilowatt hour and get 21% efficiency, the cost would be, assuming 43 kwh per kg of $4.30.  At higher numbers for kilowatt to kilogram, the two begin to be comparable.  Not sure on that one.

The bottom line is that there's no big advantage with aluminum, but it does have the disadvantage of being a more complicated process.