Things get more interesting when grid power goes out. The inverter has a switch build into it, and as soon as it senses the grid is gone it very quickly throws that switch. It will continue to convert battery power to grid power, but now only the second breaker panel with essential household loads will receive power. The main breaker panel will be without power, just as before, so any linemen working down the road will not get electrocuted. Switching over is so fast, in a matter of milliseconds, that you will not even notice. Power will now be provided by the batteries and wind turbine. When the inverter senses the grid is alive again, it will sync up its output with the grid, and throw the switch once again, restoring things back to normal.
The loads of your house are separated out into two groups, essential and non-essential loads. Essential loads would be things like your furnace, water pump (if you are on a well), some lights etc. The main breaker panel will contain everything else, including loads that are simply too large to power through the inverter, such as an electric cook top, air conditioning etc. Only the panel with essential loads will receive power when the grid is not working. Of course, if grid power is available both panels have power. Inverters and battery banks can be made very large, so if you really want to, and do not mind spending the money, it is entirely possible to do away with the main breaker panel, or rather, the panel with essential loads will become your main (and only) breaker panel. |