Working the power problem again

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This post goes in the off-the-grid power subseries.

As I mentioned in the last post, the freezer will take up too much power.  However, is that also true of the dehumidifier?

Checking that out.  The Frigidaire model I was looking at draws about 750 watts.  That's less than half of the freezer.  A look at a guide at Home Depot suggests that it may need peak power of about 3 times that much in order to get it started.  Let's say 2250 watts.

In order to run this thing, it has to get started and kept running.  For that, you need at least those 2250 starting watts, plus 750 watts times the number of hours running time for collecting water.  The dehumidifier has a capacity of 70 pints per day, or about 3 pints per hour.  If you want 4 gallons of water, that's 12 pints, so that's about 4 hours.  That's 4 hours times 750 watts, which equals 3 kilowatt-hours.

Three kwh is a lot to store in some batteries.  In order to handle 4 solar panels that I was looking at, it's going to take a couple of 258 amp batteries.   The batteries will have to be fully charged in order to do the 4 hours, and that doesn't count the other uses for electricity.  There won't be enough electricity go around for 4 hours---that's the bottom line.

Now for the big item, which will be the inverter.  A pure sine wave inverter is what is needed, and it looks like it could go from anywhere from a thousand bucks to two thousand.  The one thousand dollar one is on Ebay, and it will be shipped from the far east.

That's where I stand now.  Looks like 4500 bucks or so, not counting other hardware.

The dehumidifier is key, as it is needed for in situ water production.  Take that out, and the electricity issue gets a lot cheaper.