Someone asked about the freezer battery backup we have up here. First off, this is the work of one of my neighbors, and it was mostly done before I got here. Yes, we would like to bring it into the 21st century. But the thing is, it works. And is reliable, simple to maintain. And has NO fancy proprietary tech.

Yes, we have mains power and still use it for most things. 

Years ago, they dug a deep well and installed a water tank at the top of the hill.  So all our water is gravity-fed from the tank. The well needed work. So my neighbors decided to put in a new pump and water filtration system. They are the kind of folk that overbuild everything. With a strong emphasis on reliability and maintenance. The well pump is a 24-volt motor submerged. So they decided to build a bank of 24-volt, deep-cycle, marine lead/acid batteries to back up the well pump. They needed a place to put them and keep them dry and ventilated.

So they built a 24' by 24' concrete block shed with a metal roof over the well head. This worked well, and they had a lot of room for storage. As new people moved up here, someone decided to put an old chest freezer in that shed, and then the discussion started. Could we share the freezer? This more or less led to the 'community' we now have.  This was not intentional. Nobody decided. This community grew organically out of need and friendship. There are 14 humans (minus the two young adults away at college) that share the well and other infrastructure. 

The freezer had a 120-volt compressor motor, and my neighbor decided to replace it with a 24-volt motor and hook it into the well electrical backup system. This worked. And over the years, we have expanded.

Today, there are 800 watts of solar panels next to the block house. 2 chest freezers, 1 stand-up freezer, all converted to 24 volts. We expanded the battery bank to 16 large 24-volt lead/acid batteries. An electrics control panel, with an inverter, and other controls.

Most folks ask, "why lead/acid and not some new lithium-ion batteries?" The answer is this was NOT a planned system. It all grew from the well pump. Plus, it is simple, well-known, off-the-shelf tech.