First you cannot do anything without the owner's written permission ... no solar company would attach panels to a roof you do not own as they can be sued by the landlord. The landlord would have to be the contractor not the tenant.
https://news.energysage.com/solar-panels-for-apartments-and-rental-properties/
Now if a renter wants to take advantage of the solar credit you can invest in a portable system that you can pack up and take with you when the lease is over ... https://www.solarreviews.com/blog/solar-panels-for-rental-homes-and-apartments
And lastly ... the wording the IRS uses in the form 5695 instructions all indicate home ownership ... the form 5695 solar credit cannot be used on rental properties however there are other credits for landlords that may apply. Sadly the IRS instructions do not always spell out everything in detail ... read the entire section :
Who Can Take the Credit
You may be able to take the credit if you made energy saving
improvements to your home located in the United States in
2018.
Home. A home is where you lived in 2018 and can include a
house, houseboat, mobile home, cooperative apartment,
condominium, and a manufactured home that conforms to
Federal Manufactured Home Construction and Safety
Standards.
You must reduce the basis of your home by the amount of
any credit allowed.
Main home. Your main home is generally the home where
you live most of the time. A temporary absence due to special
circumstances, such as illness, education, business, military
service, or vacation, won't change your main home.
Costs. For purposes of the credit, costs are treated as being
paid when the original installation of the item is completed, or, in
the case of costs connected with the reconstruction of your
home, when your original use of the reconstructed home begins.
Costs connected with the construction of a home are treated as
being paid when your original use of the constructed home
begins. If less than 80% of the use of an item is for nonbusiness
purposes, only that portion of the costs that is allocable to the
nonbusiness use can be used to determine the credit.
Association or cooperative costs. If you are a member of a
condominium management association for a condominium you
own or a tenant-stockholder in a cooperative housing
corporation, you are treated as having paid your proportionate
share of any costs of such association or corporation.
Also the solar credit is not allowed on a rental but can be on a business use property that again you must own : https://www.thetaxadviser.com/newsletters/2017/oct/credit-residential-solar-panels.html
