.- I also have done as one poster above said;  Price to be determined  by an appraisal or an agents BPO/CMA or at minimum $NNN price which ever is larger.Except for Texas which I don;t recommend lease options unless you study under John Jackson, there are no state regs on the lease option scenario.The bottom line on LO and its scenarios is:- treat the buyer (and seller) well. 

Let's say you put in a $15,000 solar system and no longer have t pay an electric bill.

They are called "pen guns" and disguised to carry in your shirt pocket. 

As others have mentioned, you should try t calculate the IRR of your investment, it will take all these aspects into consideration.

My realtor in the area is Ken Mayer at HUNT Real Estate ERA, T: 602-750-3678, License #: BR529794000.

Buyer t pay $5K above appraised value up to agreed purchase pricePurpose of sell is a 1031 exchange. 

These lenders are slightly above bank rates, but with the longe amortization the 30-yr can still keep your monthly PITI competitive with the 25-yr am offerings from the cheaper bank-type lenders.Also, when you say 21-units I wasn;t sure if you meant a portfolio of 21-units across a portfolio of 1-4 Unit properties, or a 21-Unit MF?

Alternatively depending on what type of system you have and how well it's designed you can do a control with out door temperature reset and no t-stats at all.

Lots of folks losing their shirts on this currently, especially in Ontario.

That's true almost to a "T".