Solar Power in the Desert

I had the opportunity to assist a friend in the building a off-grid solar system in Arizona. I spent about four days in the desert on the project. He purchased all the components separately and the frame for the solar panels was built from scratch using 3X3 and 2X2 steel tubing as well as 1X2 steel "C" channel. There was a lot of digging, welding and concrete mixing to lay the footings, the whole array will be 64 feet long. I had to leave on Saturday and we had completed the frame for one of the four solar arrays. Each array is 10 panels. The panels are 230 watt 24 volt type. So one array is about 2.3 kw. The panels are wire in two banks of 5 panels in parallel. This will provide a target voltage of between 120 to 180 volts DC depending on the temperature of the panels. A rough line drawing of the components are below.

When completed the four arrays will deliver 9.6 kw. Each of the four panel arrays will have its own MPPT solar charger. The charge controllers will be configured for 24 volts and the battery array will be eight (8) 12 volt 200 Ah batteries wired in a series parallel for 24 volts. So that will be a 800 Ah capacity at 24 volts or 19.2 kwh of storage. With an average of 5 hours of solar collection a day in this part of Arizona the array can deliver 48 kwh per day. This should provide full charging of the storage batteries as well as plenty of capacity during the day to run loads while charging (Air conditioners and swamp coolers in the  summer). The site is a 100 acre ranch with many power needs including pumping water for a 60 acres of citrus orchard, running a house, shop and an RV.