My guess is there isn't going to be a clear answer based purely on math and analytics, so what makes the most sense for your current life and your future goals? 

It's a tax deduction pure and simple, not a tax credit.

I mean, it may cash flow 100$-200 per month of pure cashflow.

My goal is to spend 2-3 months a year there and rent it out for the remaining 9 - so I am not sure this initial property will be for pure investment purposes. 

Batteries in those units last much longer than WiFi due to the wattage of the radio.

Everything is pure profit after that.Do the math and see if it makes sense to you.

Is it something for pure profit?

@Tracy LeGrandAre you looking to do an MTR/STR for purely investment purposes and to have something to manage/work on in retirement?

If you are in a heavy sun, high cost of electricity and high rate of usage market, and you buy the panels, and you can resell to the provider rather than maintain your own batteries, you probably will make money especially if you hold long enough.

We both got in trouble for simple battery.