Connecting grid tie-in with battery back-up to home circuits via crit load subpanel.

[djimm100]

Hi all.
I want to install a pv system with battery back-up that works during a power outage. I understand that the pv power is routed to an inverter that transfers power to either the main breaker panel (and the grid) or to a critical load subpanel that bypasses the main in the event of a power outage. I understand that the wiring to the main is via a breaker, but do not understand how to connect the subpanel to the house circuits. Do I just pigtail the wires to the appropriate circuits sometime after they leave the main panel's breakers?
Thanks ahead of time.

[inetdog]

Hi all.
I want to install a pv system with battery back-up that works during a power outage. I understand that the pv power is routed to an inverter that transfers power to either the main breaker panel (and the grid) or to a critical load subpanel that bypasses the main in the event of a power outage. I understand that the wiring to the main is via a breaker, but do not understand how to connect the subpanel to the house circuits. Do I just pigtail the wires to the appropriate circuits sometime after they leave the main panel's breakers?
Thanks ahead of time.

If you are going to supply the load circuits directly rather than through having them all on a sub-panel, you would have to put in a transfer switch for each of the circuits. If you do not do this the backup power will just feed back through the breaker to the panel and from there to the other circuits.

The standard way to do what you want is to put all of the circuits which will need backup power (and only those circuits) in one subpanel. You can then put a single transfer switch that feeds that subpanel either from the main power or from your backup power system.

You do not seem to be recognizing the difference between a breaker (on-off) and a transfer switch (A to Load or B to Load but never both, so that A is never connected to B.)

[Naptown]

What you are describing is a hybrid system
Xantrex makes an elegant version of this in the xw series.
I will warn you that it is pricey

[Sunking]

It is called a Hybrid System and as rich points out Xantrex makes them. They have a built-in Transfer Switch up to 60 amps for Emergency Loads. It requires you to install a Sub Panel and re-route/re-wire you house wiring circuits to land Emergency Circuits in the new sub-panel. Also note it requires you to have a generator. It gets real expensive real fast.

Smart money is a grid tied system with Generator for those rare times power goes out.

[SunEagle]

I just saw an article today that mentioned the SMA inverter company will be offering residential battery systems later this year and SolarCity has plans to launch a combined PV and storage system in 2015.

While this seems like a great idea I would think the costs would be staggering.

http://www.intelligentutility.com/article/13/11/metamorphosis-distributed-resources-transform-grid?utm_source=2013_11_05&utm_medium=eNL&utm_campaign=IU_DAILY&utm_content=410609

[Naptown]

I just saw an article today that mentioned the SMA inverter company will be offering residential battery systems later this year and SolarCity has plans to launch a combined PV and storage system in 2015.

While this seems like a great idea I would think the costs would be staggering.

http://www.intelligentutility.com/ar...content=410609

SMA has had the Sunny Island for years now
Solar city is looking for a use for used Tesla Batteries.