Go for solar power. 

How often is it in AZ that people pay cash for solar panels? 

Our contractor said we should definitely replace the electric panel, but might be able to get away with using the old wiring.

In this case you not only need to upgrade the panel but also the wiring coming into the panel.  

.- Both boilers installed new 2017- Both electric panels upgraded 2015  - Shared Backyard access for bottom 2 units- No Parking, No Central Air- House built before 1900- Roof about 20Yrs old- Assume Fed cuts rate at least .25 point later this year Any thoughts would be appreciated.

Many years ago I was speaking at an IMN convention on a panel where the other three panelists had more than $1B of notes under management.

Mine is a 4 bedroom with solar for $3.6k.

They have great networking events, panels, programs, etc. 

There is already several offers from solar lease companies to lease a portion of the property. 

They are more likely to seek out properties with green certifications, solar panels, energy-efficient appliances, and smart home technology that reduces energy consumption and minimizes environmental impact.Preference for Flexible and Multifunctional Spaces: With the rise of remote work and flexible lifestyles, Millennials are redefining the concept of home space.