Solar installation plan

DIYGST

I have a half baked plan here looking for more opinions.

This summer I am planning a small solar system, consist of 120 Watts of panel on the backyard shed's roof. (just the hobbyist grade panels)

Dig trench to get close to crawlspace vent of the house.
Put 10-12 gauge high strand count copper wire inside the conduit and in the trench, wire run will be approx 50 ft.

Connect solar panels wires, run through trench into crawlspace vent, into a battery controller made for solar use, keeping charge of 1-2 deep cycle batteries in the crawl space. 1 pair of 12V DC wire going up into the room where there will be a automotive type inverter /w sine wave signal to convert to 120 VAC, maybe 150W or 300W capacity.

So now I have 120VAC to power something, I need get it into another room. I plan to use one of this:
http://www.monoprice.com/products/pr...seq=1&format=2

To relay power to another room with romex wiring, maybe to power light duty stuff like laptop and desk lights. Label new receptacle as solar (I will know anyway). Maybe add another one in another room.

That's what I have so far.. didn't want to put battery in the shed.. the crawlspace has milder temperatures. And also the amps from the panel is relatively low so it can be carried though the trench without much trouble.


Details: a fuse on the 12V battery + terminal would be better.
Can grey conduit be buried? Since this is not high voltage does it matter how deep the trench is?

Yoyizit

4 hrs/day of 120w = ~500wH into batteries.

150W/300W draw each day from 50% eff. batteries gives you 1.7/0.9 hrs of operation.

Batteries need to be 20 A-hrs.