Inexpensive Solar system

Solar panel Notes:

Optimum angle for solar

              Fixed--~30 Degrees

Two season

              Summer (march 30-september 12^th)- ~8 degrees

              Winter (rest of year ~45 degrees).

Sites:

http://www.solarpaneltilt.com/

http://www.pveducation.org/pvcdrom/properties-sunlight/solar-radiation-tilted-surface

Note, angle for grid-tie is very different than off-grid.  (because you are watching for optimal energy generation the whole day.

For the mini off-grid installations, current position is good for winter (until march 30), lay on top during summer.

Batteries for mini-grid

System works for either 12 or 24 volt battery systems (however, you need different output systems for 24v)  For simplicity, I recommend all small systems stay at 12v.

You can use 2 6v batteries in series to get 12v, but they must be very very similar.

Checkout of Battery

Battery checkout is the most dangerous step.  It is a little safer to do battery checkout with a smart charger (from 110), but it can be tricky in other ways.  (I had fully discharged batteries take days to recover on a charger, but I think the charge controller would have quickly worked).

Do not attach a battery directly to an array of batteries.  (Even a good battery could rapidly charge, generating hydrogen, and explode, spraying sulfuric acid.)  Battery testing should be done outside.  Batteries should always be on a thermal insulator (like a piece of wood).  Lead-acid Batteries are not really a fire risk.  (all types of lithium batteries are a fire risk because they have ~10x energy density).

The Charge controller to battery hookup has clips for this reason.

#1 measure new battery voltage (should be between 9 and 12 volts, but not necessary).

#2 remove clips from existing batteries and attach to new battery (battery should be at least 30#s).

#3 measure new battery voltage (do this during the day).  Within 10 min battery should be between 9 and 12 volts.  If battery is not quickly moving to 9 volts you may have a problem.

#4 Everything should work right away, but avoid placing heavy loads, and night use

#5 Every evening and morning check the battery voltage to get a feel for self-discharge and capacity.

Loads

The charge controller is a 42v 30A device.

That means that if any circuit goes over 42v and/or 30A, at least that part and likely everything fails.

So voltage open circuit (VOC) of the solar panels should be less than 42 volts.