Tuesday, June 30, 2015

Bus power!

Today I had a wander through hardware stores. I was particularly interested in solar power options and alternatives. It was fascinating! I went particularly to Harbor Freight with the intention of buying a suitcase solar panel. The visit didn't start out too well because they had a big sale sign outside yet inside the prices were the same as normal. Fake sales signs

The suitcase solar panel was $80 but to make it work, it needed a charge controllers that was $25 for the cheapest and $80 for the next. The suitcase panel would provide 13w in theory. There was a 3 foot panel that was $70 and claimed 15w. Things were beginning to look costly in Harbor Freight!

In normal electrical theory, watts are the product of volts and amps. Harbor Freight seems to have a different theory as the products never worked out on any of their boxes, leaving me in a quandary as to whether the bits would all work together since either the volts and amps were off or the watts calculation was wrong.

I added the costs... $80 for a cheap panel that's not quite what I want plus the next model up of charge controller which was $80. Then add a decent inverter at $200 then add a 35ah battery at $60 or a 105ah battery from elsewhere at $80. That started at $460. I can see exactly why people use gas for cooking and water heating!

At $460, a simple Harbor Freight generator at $120 that produces 800w looks much more useful. Set that going while cooking or heating water. While solar is cheaper longer term, at $3.50 a gallon and at a reported 7 hours per gallon, that could power my 700w microwave of my kettle or a phone charger quite satisfactorily. If it was run for as much as half a gallon a day ($1.75) then I could use it for 194 days before I'd even equal the cost of installing a 13 - 15 watt solar system. The solar system would produce an optimum 8 watts over 12 hours or 72watt hours while the generator could produce ten times as much in a twelfth of the time! Solar doesn't look so rosy now!

In general, I'm tending to think of running with a generator only initially then adding batteries, inverters and charge controllers later, followed by a gradual introduction of solar panels. All food for thought.

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