I’ve been planning a detached accessory dwelling unit (ADU) for some time, and hope to finally begin construction this spring or summer. I’m planning to build to Pretty Good House standards, and install enough solar panels that the ADU will be net zero energy, with some excess generation to supplement energy for the main house (both units will share a meter).

It seems to me payback time for the panels should be more rapid than if the project was just owner-occupied, because with panels, the portion of the rent covering electricity will be income for me as the landlord and electricity supplier, rather than merely offsetting my increased electric bill if I didn’t have panels.

Is that logic sound? Does anyone have experience to share building and managing a NZE rental?

For what it’s worth, I live in a college town where the going rate for rent will more than cover monthly payments on the home equity line of credit I plan to use to finance the project, even with increased cost of panels and better-than-code insulation, air-sealing, etc.