I am getting close to investing in a micro-inverter (Enphase M250) based grid-tie solar array for my home, but am concerned I won't be able to use the solar power during grid outages. I found a similar post here that hints towards spoofing the solar array to power on.
First, is this actually possible? I understand I would need to disconnect from the grid before enabling the solar array and would turn all but the necessary circuits off at the panel.
In my mind, I'm thinking a pure sine wave split phase inverter, like this, hooked to my truck battery and fed in through my 220v, 50A welding outlet would enable the micro-inverters to start producing power again. I would then charge the battery with a float charger. Is it that simple?
Second, if that would work in theory, how much load would be on the inverter? Let's say I am producing 10kW from the solar system and have a load of 7kW. I'd like to think the 4kW inverter wouldn't have any load on it, but I have no idea. I'm concerned it would try to pull from both (or possibly only the inverter?) and fry the split phase inverter or destroy my truck battery.
Third, if I am producing 10kW from the solar array and only using 7kw, is that going to be an issue? Normally the grid would consume the remaining power.
Lastly, I do realize there are plenty of options, such as a battery backup system, or a hybrid inverter, or a string-array with a SunnyBoy inverter, which has a usable outlet during grid outtage. I'd like to enable the solar array with very little extra cost then what I'm already prepared for and without modifying the system, since it's all under warranty unless I modify it (as in tapping into the DC lines from the panels). Also, a very similar question was asked here, but I'm hoping to answer the technical aspects of 'is it possible', not as much of the 'is it advisable' question mostly addressed in other post.
EDIT: I also found a document from enphase about AC coupling their micro-inverters here, but it doesn't spell out specifics. I'm convinced it's possible...
EDIT: I've contacted my installer, who agrees that it should be possible, and is contacting the manufacturer for more details. I still have my fingers crossed.
FINAL EDIT: For anyone else looking for a similar setup, I received a response from my installer. The Enphase microinverters absolutely will work with any "clean" power source. As the accepted answer points out, the microinverters are already designed for this very purpose. They don't care what the source is, they'll match it as long as it's a stable power source. My installer did say if I don't use a clean power source and fry the microinverters, they won't be covered under warranty, so be careful of the selected power source.