paulcdb

does the system wait for electricity to flow in before it flows out?

Basically, yes!

If you unplug the micro inverter, it’ll cut the power within milliseconds of it detecting no electric signal. AC alternates around 50hz in the UK which the inverter detects and starts generating. Once it losses the hz signal it stops.

I really question the ROI on this sort of thing

Depends if you do it right.

In the UK, you can buy 2 ~400w for about 140, then £100 for the micro inverter. I have 4 295w panels mounted on a flat, raised frame on the side of a shed and they cut my bill from £150 down to around £70 last month. So yes, they can pay for themselves pretty quickly.

And once they’re paid for, it’s all free electric! And we’re now seeing batteries with plugin style so you can store the electric to run white goods, saving even more, etc.

Also, unless you get a solar tracker, “optimally aligned” isn’t really possible. The sun moves inclination every day depending on where you live. Here in summer you’d want a more horizontal position, in winter a more vertical position which is why solar fencing is actually becoming a thing because they generate more in winter.