Solar panels can be bought exactly in 18 months from the provider as per contract. 

Has anyone done the analysis on solar panel systems for  their STRs?

The new window is larger so I tore off the wood paneling and have access now. 

Consider whether the panels add or take away from the value of the property as well.

The best part of the bootcamp are the panels by other investors and what they are doing in their market.

I was looking into the possibility of small solar panel arrays... not large solar farms.. to create some cash flow on land that has no working farms.  

Sounds like the one building also hasn't had the electric separated; each unit should be individually metered, and a breaker panel for each put into place and electric separated for each unit; there should also be a "house" meter and panel for the landlord to pay for common area electric (such as public lighting around the property).One other thing.

But why didn't you keep the 70's wall paneling? 

Typically arises when a landlord has a building with a common area that has lighting, such as a foyer or hallway, but the wiring for that lighting is connected to a tenant’s electric panel and meter; it can also be something that consumes even more energy such as a laundry area that is available for all tenants in a building but the wiring goes to a single tenant’s electric panel and meter.That is why when utilities get separated in a building that the owner needs to realize that an extra panel and meter must be installed for the common areas, with billing for that common area meter going to the landlord.Some BP links that discuss this a bit more:https://www.biggerpockets.com/forums/84/topics/75044-installing-common-area-electric-in-a-3-4-unithttps://www.biggerpockets.com/forums/52/topics/107306-triplex-without-seperate-utilitieshttps://www.biggerpockets.com/forums/52/topics/72185-water-sewer-bill---what-to-do-with-it?

Get familiar with the house, know where the main shut-off valves are, know the age of the existing systems (HVAC, water heater, electrical panel, etc.).