Power out backup without solar panels

jimskau

I am a "stand alone" solar installer in Southern Spain. Recently I have had inquirers on backup systems for people on the grid. The trick is to make any backup system as simple and cheap as possible. The power outs are rarely more than 10 minutes long, but a nuisance as they reset satellite boxes and other electronics.
I would think a Grid charger/Inverter would be necessary to ensure security for other people during power outs, plus a small bank of 250 Ah to run the Inverter during power failure.
The Inverter would have to be on 24/7 of course, but what about the battery charging?
Could there be a cheaper option in buying the charger separately?
My problem is, that I have no experience with grid tied systems. I will get a qualified electrician to do the actual connection to the grid, but I need a list of what is necessary to source and build the system.
I hope this is not too much to ask, and send my humble thanks in advance.
Jim Skau

Windsun

Re: Power out backup without solar panels

There are several inverters made for just that, including at leasta couple of the Outback Power ones.

crewzer

Re: Power out backup without solar panels

Jim,

A backup UPS (uninterruptable power supply) is probably the simplest and cheapest solution. They include a transfer switch, an inverter/charger, and a sealed battery pack. Just plug one into a wall socket, and plug the load(s) into the UPS. When the grid is up, it powers the loads and uses the charger to keep the batteries fully charged. When the grid is down, the batteries power the loads via the inverter. UPS’ are commonly used for desktop computers and servers.

HTH,
Jim / crewzer

jimskau

Re: Power out backup without solar panels

Thanks Crewser!
Yeah I figured that would be the solution. No need to get grid tied with that relatively short timespan of power outs.

BB.

Re: Power out backup without solar panels

Some of the Outback and Xantrex inverters actually seem make very good UPS's too (automatic switch over, good battery chargers, lots of control options like generator start and such).

Or, look for used UPS's... We were flooded here in the US with tons of computer room UPS's from the dot.com bust. Might need to supply new batteries if they have sat for awhile.

On the other hand, a small UPS good for 15 minutes running a small computer is about $100...

-Bill

niel

Re: Power out backup without solar panels

bill brought up the used ups as an option and it can be a good option as even i had managed to pick up 3 500va tripp-lite ups with new batteries for $25 each. i placed one on a common light so as to not trip in search of where i put my flashlight and one on the pc obviously. the last one i'm reserving for a special purpose having to do with my home security.