Batteries are Cheap, Backup power is expensive

@billpete  - Yeah the economics keep changing.  Costs of power generation have dropped  a great deal recently, making selling power a bad idea, but now with climate change and AI's demand for power it may make home power generation more worthwhile. 

One point that hasn’t been addressed is that makes a UPS more expensive than a stand-alone battery/inverter set up is that the UPS is able to take over within Miliseconds, allowing most electronics to continue running seamlessly. That’s actually not trivial to do. 
 

If you really just want cheap battery backup nothing beats lead acid - parallel a dozen car batteries and hook up a 2kW or 4kW 12V inverter.  I did the math recently and in terms of energy-per-dollar lead acid is still way ahead. And they can easily be maintained with a cheap trickle charger. 
 

That said, we have a system with solar (roof and ground based installation for around 20kW total) and several Tesla Powerwall batteries - with us enough to keep us going indefinitely without grid power. I also have an ancient trailer-mounted 60kW diesel generator (enough for a small city block) for long periods without sunshine. The diesel in my fuel trailer will last a good while with a good fuel stabilizer. And I use it occasionally for vehicles so I cycle through it. (The generator eats about 35-40 gal/24 hrs, so with any 400 gals on hand we’ll be ok for a while)

 Now, to tie it back to Audio, I don’t hear a difference between grid power and solar/battery power.  I do have isolation transformers for my system so that might help.  When the generator is running I don’t hear anything but generator noise though …

@erik_squires

I use battery backups on all my electronics because they have good surge protection and when the power flickers, they protect expensive equipment from damage.

I have a backup generator that kicks on automatically after 30 seconds of outage, but generally whole house generators have relatively dirty power, so the battery backups continue to provide low voltage protection as well as surge protection.  If you want to spend a bit more money, you can use true sine wave battery backups.

The only downside is the batteries do need to be replaced in all of them from time to time, but if you’re a little bit handy, 3rd party batteries can be had for a fraction of APC replacement battery costs.

Having your own power is an interesting idea and I love it except for one thing: You are now responsible for fixing it when your home power generation  fails. And while you can hire people to do that for you, in an emergency, those people may not be available for weeks.  So you need to think about the maintenance of voltage converters, batteries not first year or second year, but when it’s 10-15 years old.

Hey @phildebrandt - Make sure you compare usable power.  LiFePO4 batteries can be used for almost 100% of their amp hours (Ah) while lead acid 50%. 

If you have the room, I can see lead acid beating out LiFePO4 for $/usable watt hours. 

Great point @erik_squires ! I hadn’t thought about that limitation when I did the calculation. That was for an old EV Restauration project (a 1910 Baker Electric) and I ended up with a stack of golf cart batteries that nicely took the place of the original Edison batteries.  I would need to look at it again. 
 

@tomrk The point about dirty generator power is very real. I think going forward I would only use an inverter generator, and I’m looking into running my generator output through one of my solar inverters (convert to 480 V DC and then let the inverter create clean 120/240V AC)

Now, inverters pollute the power with their switching frequency, typically just outside the “audible range”, at 25kHz give or take. That’s why I mentioned that I have isolation transformers to deal with that before it reaches my Audio gear