Thursday, November 12, 2015

The Power Budget

The reason I'm putting in a 120V plugin is because solar and battery power are so horribly expensive. The reason I'm going with a bucket and Jerry can approach to water is based on cost also.

In my eagerness to proceed, I've forgotten my underlying principle of low cost. I've also allowed myself to be trapped by the hillbillies into following their ideas and plans. The electrical box the hillbillies put in was ludicrously large for just a cable compartment! It looks kinda sensible to use it for batteries.

The microwave would use 1200w at 120v. That's 10 amps! Without even considering the losses from using an inverter, running the microwave for 15 minutes would burn up a lot of power. Converting 1200w at 120v to 12v would be 100 amps. Given that a full battery holds just 105 amps, discharging it in 15 minutes would probably melt it!

While it would be possible to provide 100A at 12v, it could take quite a few batteries. Certainly more than the planned two! Thus, where the battery compartment is planned probably isn't the best location.

The big door put in by the hillbillies is a huge red herring, in my opinion. Far better to rivet the hillbilly battery door closed, make a smaller compartment and door for the 120v supply.

As far as electricity generation, solar panels seem quite pricey. As the roof is curved, flexible panels make the most sense. At $200 for a 100w panel, solar isn't cheap!

In terms of other power usage, I'd be charging my phone, batteries for my lanterns etc. No heavy usage save for possibly a fridge. If it was a Peltier fridge then the usage would be 5AH or 60W.

Although I don't like gas, it looks like being the sole solution for cooking unless the bus is plugged into a power supply. Refrigeration, small battery charging, ventilation etc could all be run straight off solar with a cool block in the fridge to maintain coolness at night. Perhaps a small 6v battery to maintain cellphone charging capability at night.

Looking up NiMH cells, it looks that once one goes beyond AA and AAA cells, prices rocket. That is rather frustrating!

Looking in another direction, generators have a place. A well installed 1800W generator could charge a single battery while providing power for a microwave. The trick there is to set the generator for remote start and remote stop.

Whichever electrical solution there is, looks like being several hundred dollars. The cheapest is gas and no electricity. There is, of course, no reason at all why gas couldn't be the initial solution then electricity later.

Meanwhile, I'm reconsidering welding. It might be fun to have a go at some welding.

No comments:

Post a Comment