Add second power system to barn?

[bbells]

I am sure this has been asked before, but I can't find it. Sorry if it is a repeated question.
I am adding solar to my barn. I currently have AC power in the barn. For the most part I can get by with DC LED lights, a DC tank heater etc. But, there are a couple things I need 120v AC for. Is it practical to add a DC power distribution system and just add an inverter where needed and turn it on when needed? Or, would it be better to keep the current grid AC in some outlets and solar powered DC in others? Does anyone do this? Or, is it better to just use an inverter to power AC to the current wiring and just use 120v lights, etc. (as long as I separate it from the grid, of course)?
I guess the question is: Separate grid AC and solar DC power distribution systems, or have AC on all outlets via an inverter and separate from the grid? Thanks for any help.

[organic farmer]

One of my neighbors went off-grid in the 1980s. His house is entirely 12vdc. By far the cheapest and least complicated system I have seen among any of the off-grid setups around here. He uses a $20 Chevy voltage regulator. His battery bank is all 12vdc car batteries in parallel [he gets used batteries at the junk yard for the $10 core charge]. Once a year he tests each battery individually, any battery with a bad cell gets replaced with another from the junk yard. He has less money tied up in his entire battery bank then what most modern systems spend on a single battery. All of his home appliances are 12vdc.

[SunEagle]

One of my neighbors went off-grid in the 1980s. His house is entirely 12vdc. By far the cheapest and least complicated system I have seen among any of the off-grid setups around here. He uses a $20 Chevy voltage regulator. His battery bank is all 12vdc car batteries in parallel [he gets used batteries at the junk yard for the $10 core charge]. Once a year he tests each battery individually, any battery with a bad cell gets replaced with another from the junk yard. He has less money tied up in his entire battery bank then what most modern systems spend on a single battery. All of his home appliances are 12vdc.

Sounds like your neighbor has gotten lucky getting cheap but still usable batteries. I bet he does spend a lot of his time making sure those batteries stay as healthy as possible.

I would imagine that for most people getting low cost components is not possible. That is the reason just about any off grid system using batteries will cost 5 to 10 times /kWh then purchasing the same power from your POCO.

[ButchDeal]

he is also not using a lot of power. He either has short DC runs or batteries distributed around the home.
There are 12V appliances out there but they tend to be under powered and costly. For example look for a 12V microwave, I think the most powerful is going to be 800w. Half the money will get you a nice 1500W microwave AC.

[Logan005]

time = money, The time required to test and maintain so many less than idea batteries would be cost prohibitive for many, technical expertise and patience is lacked by most. I have lived off grid and have maintained an off grid system for real world testing and documentation. 12 volts is not a cheaper system when compared to a more efficient system like 24 or 48 volts. 12volts is for cars, Toys and some power tools, If you want real reliable power I would only consider 24 plus volts, with preference for 48, unwisely using 12 volt car batteries, would be much safer wired in series. a properly sized 12 volt inverter will barely power a small microwave. refuse batteries are lacking efficiency and capacity, making your already inefficient 12 volt system even more inefficient and wasteful.