The latest issue of the IAEI magazine has an (actually readable) article on a new twist to alternative energy: the micro-inverter.
Personally, I think this is an idea whos time has come. Where it matters to us is that it radically changes the way secondary power sources are tied into the system.
In the 'conventional' arrangement, all of your generating sections are tied together, and a single feed is brought to a single inverter that, through a transfer switch, feeds the panel.
With micro-inverters, eaqch solar panel has it's own tiny (figuratively tiny - the ones in the pictures didn't look very small!) inverter. Through some means I don't understand, these inverters are all in sync with each other, and thbeir AC outputs are combined to form a 15 amp circuit, which backfeeds an ordinary breaker in the panel. Again, how these inverters 'know' how to be in sync with the PoCo is something I don't understand.
This approach, IMO, will revolutionize the solar (and, to a lesser extent, wind) industries.
Why? First of all, because it's all self-contained. You can do it without disturbing the PoCo feed to your panel. You can easily add or remove units from the system.
On the downside, you have a much greater chance of encountering a 'live' panel even when you think everything is 'off.' While the inverters are UL listed, and are designed not to supply power unless the PoCo supply is also present, I am still "cautious."
After all, how do you 'turn off' a solar cell? Throw a tarp on it?
In a roundabout way, this brings me to one of my gripes about most breakersw: there's NO space provided on the face of the breaker for you to use to identify the breaker. Take the panel cover off, and the breakers all look alike. You have no ready means of identifying which breakers are being back-fed.
I'm also not sure if there are any 'tie downs' avaqilable for single pole or 'skinny' breakers. Until now, we have assumed a back-fed breaker would be a multi-pole breaker. That is no longer the case.
Lets consider another possible arrangement: micro-inverters supplying their own panel, with a feeder connecting this panel to the house panel. Now we have a feeder that, IMO, needs to be LOTO's at BOTH ends.
What are your thoughts?
