Re: PV Grid Tied Power Outage
As ggunn says--"Simple" GT Inverter+Solar panels is "off" during a power outage and there is no "cheap" way of getting back online (even with a backup AC generator--at least reliably/safely).
There are "hybrid" inverters that can do both Grid Tied and Off Grid... This inverters still need a full sized battery bank (think the size/weight of 24-36 [fixed] car batteries for a 6kW inverter/solar array or ~600 AH @ 48 volts). And these batteries typically need to be replaced every 5-10 years.
The hybrid inverter has an internal AC transfer switch that cuts your "protected" loads (sub panel) from the grid and then supplies power to your loads. And they support the connection to the AC2 input for a backup generator too...
The hybrid inverters are not that much more expensive, but the batteries and interconnections do.
If you have reliable grid power--then a backup generator is usually the most "cost effective" solution.
If you have unreliable power, or power that is down for 2+ weeks at a time, then, possible a true hybrid solar system may make sense for you (or if you are disaster planning).
Last edited by BB.; June 29th, 2012 at 9:11 PDT.
20x BP 4175B panels (replacement) + Xantrex GT 3.3 inverter for 3kW Grid Tied system + Honda eu2000i Inverter/Generator for emergency backup.