@Schneider2bikes
You are eligible for the solar energy credit if you pay to install a solar system on a home that you use as a residence. It does not have to be your main residence and it does not have to be a home that you own. You would be eligible for the credit if you paid to install a solar system on a house that you rent. The credit is 30% of the cost, so if the system cost $10,000, you would get a $3000 credit on your tax return.
If you think that is not logical, you would have to address your complaints to Congress.
Your state may also have a credit, but you would have to investigate your state's rules to see if it was limited to a primary residence or a home you owned.
I personally would not pay even the 70% share to improve someone else's property. Real property is land plus anything that is permanently attached, and once the system is attached to someone else's house, it becomes part of their real property. I don't believe there is a legal way for you to retain ownership (title) of part of their real property, unless they are willing to modify the deed and file it with the county clerk. That being the case, I can't see any logic in paying for a major improvement to someone else's property. They may love you as a tenant, but if they die tomorrow, your new landlord might want you out, and there's nothing you could do about it.
Lastly, because you would be paying for the system, the landlord may not include the system as a property improvement for purposes of depreciation or adjusted cost basis of the property. The landlord can only take depreciation or expense deductions for improvements they actually pay for.
Adjusted basis means the following:
Suppose you buy property for $100,000 and sell it for $150,000. You have a $50,000 capital gain which may or may not be taxable. If you invest $10,000 in permanent improvements, then your adjusted basis is $110,000, so your capital gain would only be $40,000. If you only pay a net cost of $7000 for the improvement because of the tax credit, then your adjusted basis would be $107,000 and not $110,000. You only get a basis adjustment for improvements you pay for, and if you pay less for the improvement because of tax credits or utility company rebates, you can only use the lower (net) cost as your adjustment, not the full price.
But in the case where you are paying for an improvement to someone else's property, you get no basis in the improvement at all (because there is no separate ownership) and the landlord gets no basis in the improvement, because they didn't pay for it.
