However, there is only 1 thermostat (control panel) for the whole building.

I recently came upon a property being sold in Baltimore, MD that has had an upgraded HVAC, Water heater, and electric panel installed.

Licensed structure engineer report.Plumbing, dryrot (siding), termite. wall and attic Insulation.  35-50 year old home roof material warranty, gutter 10 year labor warrantyElectrical panel inspection, 100 amp circuit breaker.....100 years any tree in front.

Hi Team, Does anyone have any experience with renting a properties with solar panel?

Have them look at the water tank and furnace and see how old they are, look at the electric panel and just verify its not Federal Pacific, see if the basement is dry, how does the siding, windows, roof, porch all look, is the garage falling over, etc etc. 

We rehabbed the property, updated the kitchen, bathrooms, new boiler, new electrical service panel, and added a French drain system.What was the outcome?

Third, first deals make sure not big ticket items need to be looked at and repaired (I.e. roof, AC/Heat, electrical panel, foundation etc.)

By saying "every site that I find valuable", I mean the 200-500 sites in each state that are typically good for our use, solar.

Although, if you have any awful paneling and drop ceiling, I'd look at upgrading that after the majors are done as your first cosmetic upgrade.

That goes for other construction such as SIP (Sturctural Insulated Panels) or steel framing.