Hi Robert
Thanks for that. Yes, looks like plenty of shading going on on the north roof. If the west roof is clear, that would be make sense to maximise roof space there. The west roof usually yields 10-15% less than the north in perfect conditions, but if you oversize the inverter with panels lower yields don’t really matter so much anyway.
As for whether you would need micros or optimisers, that would depend on how many panels you could get on the north roof comfortably out of the way of any shading issues. A Sungrow inverter would allow you to put panels facing two different directions (it has 2 x MPPT inputs, as long as there is enough panels on both roofs to meet min voltage levels).
The other option besides Enphase that is very much worth considering is Tigo optimisers. Tigo allows you to have the best of both worlds - it is inverter agnostic, so it can be used with Sungrow, and it can be deployed only on the panels that you have shading concerns making is lower cost. So you might have 8 panels in question on the north roof, you can get Tigo optimisers just for those panels, which should keep the cost much lower than going full Enphase.
However, as you’ll see in this thread, there are a number of installers who think that Enphase micro inverters will give you the best financial return over a long period, so if you have the ability to pay the extra up front cost, you may be better off in the long run due to higher performance.
The final thing I’ll mention is that SMA advertises ShadeFix optimisation built into their inverters, which I’m hesitant to recommend as this is mainly a software optimisation, and I’m not sure if this is simply a good marketing spin on what most string inverters do anyway, or whether it actually works better than other string inverters. I think what is clear though is that it certainly won’t work as well as panel level optimisation (i.e. Enphase micros, SolarEdge and Tigo optimisers).
Hope that helps.
Marty