Solar Wiring Diagram

I have created a small solar generator. It consists of 3 12v DC deep cycle batteries (90ah each), a 7 amp, 12 v charge controller and 3 15 watt solar panels.

Here are a few things to note. Amp hours denote the amps you can discharge a battery over 20 hours, before you have to charge it. To figure out this out, you divide the amp hours by 20. For instance, a 100 amp hour battery can discharge 5 amps for 20 hours prior to requiring a recharge (20 * 5 = 100). In my case, I have 90ah batteries, so it would be 4.5 amps for 20 hrs. The other thing to remember is, if batteries are in parrallel (negative to negative and positive to positive as shown in diagram) then the amp hours are additive and voltage is constant (12 v, not 36). So in my case, with 3 90ah batteries, I have 270amp hours @ 12v dc, available or 13.5 amps for 20 hours. Unfortunately, I only replace 45 watts of power, so I will probably run out at some point as I need a larger charging system (depending on what I draw off). Since this is only used for a few days a month, this should be fine however. It cost me $500.

A couple points. Since I have a 3000 watt invertor (it can draw up to 30 amps), it is important that the wires used between the batteries themselves, as well as between the batteries and the inverter, are large. In my case I use 2 gauge to the invertor and 00 between the batteries. This will eliminate and voltage sag and ensure that my invertor can function with a large draw. I can successfully start and run a full size normal refridgerator with this system, as well as run a 2hp Bostich air compressor to over 120psi. This will be the system I take to and from Taos, until I have my cabin built. Once built, this system will stay there and be the power system for the cabin.

Taos Here We Come

Well we are heading back out to Taos the week after/of labor day. We will be taking some more photos, cutting the driveway into the property, leveling off a flat spot on the west side of the driveway for a shed/cabin and maybe, digging the holes for the rubble foundation. If I can get the foundation dug, I will be planning to fill with gravel. I have spoken to other contractors and builders in the area and due to the dryness of the climate, I won't need a drain tile in the bottom of the trech. Then, next year, I can place the cinder block grade beam and start setting adobes.

The cabin will be 8x12 on the inside, with the 8' side facing south and the 12' side facing east. The 8' side will have large windows to let the heat / sun in for passive solar heat. We will most likely use an earthen floor. I am still unsure on whether I will heat this via radiant floor heat or whether I will remove that for this small cabin, and simply heat with a ventless propane heater. I guess I have until next year to figure that out.

The other major item needing done with this trip, is for us to determine where true-south really is in comparison to the property lines. This will allow me to orient the buildings on the plot drawings.

Stay tuned.

Solar Works

Well I am here in Kansas City, anxiously awaiting a trip out to New Mexico. I continue to plan and we have decided to Build small cabin / shed first, which will be half the size of the guest house. The plan is start small, work it out, try again a bit larger and fix issues along the way prior to starting on the final home. The cabin will be 8 x 12 feet on the interior. I will use 8" cinder blocks on a base of rubble that is 24" deep. The cinder blocks will have the webbing knocked out with rebar placed in the webbing crevices and cement poured in on top of that. Cheap fast way to build a grade beam. I wouldn't do this on the home, but figure it will work fine for a shed / cabin. Anyway, about the solar.

Since I have a plan, I have been buying a few necessities. I have a solar shower thAt I picked up for $10 and have also created a solar generator, if you will. I have 3, 90 amp hour batteries (12v DC) in parrallel, a 7amp solar charge controller, a 3000 watt (sustained) inverter and a 45 watt solar panel. it just so happens that our power to the home went out for 14hrs on Friday and I ran my big refrigerator for 6 hrs with no real issue.

In case you were wondering,divide your Amp Hour rating by 20, to determine how many amps you can push for 20 hrs prior to needing to recharge (assuming the batteries Re fully charged when you start ). For example, 1 90 amp hour battery can push 4.5 amps for 20 hrs. A 100 watt lightbulb is about 1 amp (120v/100 watts),so I could power that for 80 hours or so.

Since I have 3 90s in parallel, I add my amp hour capacity and my voltage stays @ 12v. So I have 270 amp hours to use. My panels however only replace 45watts, so I will run out at some point depending on my use. I figure this should work for me for 3 day weekends. Have fun. My next investment is a MPPT charge controller that supports 2/24/48v solar front ends and battery backends.