Living Offgrid Affordably #16:ZZT-ZZT, The Power Inside

| 9/7/2012 12:55:43 PM

Tags: solar power, living offgrid, alternative energy, Jeff Chaney,

Jeff with his one kilowatt array After building and installing the array last time in “Power Us Up, Scotty”, we are ready to bring the power where we need it, inside the building.

The “service entrance” (picture in previous article) was located 6 feet from the northwest corner of the building, to place it underneath the first short flight of steps and landing. I had chosen to house the battery bank and peripheral equipment (to be detailed with photos in a future article) under the stairs because of limited space in this small building. This action did not conform to code, it did not allow ample room or access to the hardware. The biggest detriment was the fact that the stair treads must be removed to inspect and water the batteries. Very cumbersome. When the main house is built, I will include a “power room”.

I installed a reducer at the building end of the underground pipe, to convert the 6 inch pipe to 2 ½ inch. The smaller pipe rose about 2 feet above ground, to enter the building. The joint between pipe and wall was caulked.

Having a limited budget at the time, I chose a Xantrex C-30, 30 amp charge controller. Consisting of two modules with a total output of 14.2 amps, the array would mate to the C-30 just fine, with room to expand later.

The 1/0 (one ought) power lines were connected to a junction block. #6 wire was used for the short run from the junction block to a disconnect, from the disconnect to the C-30, then finally to the battery bank.

I had decided to use a combination of batteries for head-to-head testing purposes. This is highly not recommended! Lower performance and battery life will result. In spite of this knowledge, I am known to conduct some unorthodox experiments. I used four Optima yellow top and four Deka marine 12 volt deep cycle batteries, all wired in parallel to maintain 12 volts and multiply storage amp/hours. The Optima’s contain gel electrolyte, the Deka’s flooded lead acid. These should not be used together, but I wanted to compare them. The main reason not to combine them is that they have different charging requirements. The best charge voltage for one type is not best for the other type. As a result, one type will suffer and not yield a full lifetime.

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