Hello All! This is my first venture into the realm of true off-grid solar power, aside from the occasional solar powered toy. I am working with a remote cat colony, which has a shed with a roof angled pointing directly south, so I have a perfect spot for a panel. The shed is 10x10, with a 2x5 lobby area (supply storage) and then the rest as main cat living / feeding area. I want to power a small 12V oscillating fan, such as Hopkins SP570804 Go Gear 12 Volt Oscillating Fan ( http://smile.amazon.com/dp/B003SS62PS/ ) either continuously (summer months) or during daylight hours (winter). The shed has two small windows and a small door that is open during the summer months, but even then, it bakes with no air movement. Duration of fan ON is more important than the amount of airflow (e.g. in the summer, I would rather have continuous low fan than high fan for 12 hours a day) The fan timing would likely be done with uxcell DC 12V Digital LCD Power Programmable Timer Time Switch Relay 10A (http://smile.amazon.com/dp/B008999RYY). I could program it for the winter months, but then just have the volunteer hit the manual ON button once it gets warm, and let it run, run, run... I also want to have two LED lights on a light switch, so when the volunteers show up after dark (think winter), they can flip a switch and have light in the lobby (storage area) as well as in the main living area. Right now they are using head mounted LED lights. Figure on 1-2 hours of lights on per day, max. (SeaSense Super Bright Interior Light Surface Mount LED http://smile.amazon.com/dp/B001HPJLBG ). I have NO idea how much power I would need, so I'm trying to figure out if I need a 10watt or 20watt panel, what size battery, what kind of PWM?. I want to be able to install this, and forget it. Would a 12V 7A battery, such as a UB1270 be enough, or do I need a larger battery? A 10W solar panel? 20W? I'm the building / tech person, but I am not local to the colony; the 3x weekly volunteers will not be technically inclined. It "just needs to work". I can do the wiring (I've done a bunch of home wiring), so I can handle that. I will likely be using metal-shielded wire (bite-proof). I would like a PWM with some sort of indicators / panel, so if the system is malfunctioning, the volunteer can call me and say "There is this LED on" or "the panel says this". The shed is literally out in the middle of a field, so there are NO sun obstructions, other than the occasional tractor.. Oh, and 2 bars of 3G service, so remote data connections are out. Oh, and of course, keeping it cheap would be nice. Under $200 is definite, closer to $100 would be nice, since it out of my pocket. That's a lot of cat chow (320#, roughly) If any of the specific items are a non-starter, let me know - I thought that providing as much stuff up-front as possible would be a help. Thanks in advance... James
I'm a total novice / noobie when it comes to the math. I used a 30 watt kit and am using a huge (group 24 / 1000 cranking amps) deep cycle marine battery to run an aquarium pump pretty much 24 hours a day for pond aeration. My panel only sees about 3 hours direct light due to some trees that need to be flopped, but it's pretty much keeping up unless it's cloudy for several days in a row. Best of luck !
