I'm looking for information about the 30% tax credit available for geothermal installations.

The situation: Property owner is considering geothermal installation in home another family member lives in (rent-free).

According to IRS form 5694, the home does not have to be the "main home" (where you live most of the time).  However, I infer that it does have to at least be ones "home" (where you lived in a given year) .  Unfortunately, the owner can't honestly consider this a "home".

Questions: Is the owner or the occupant eligible for the tax credit?  This is the "main home" for the occupant.  Does one have to own the property to claim the tax credit?

Any insights would be appreciated.

I'm not a tax expert. I read the form as you have. That is, that the wording is home, not house or property. "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, will not change your main home." I would think that "The home does not have to be your main home." would mean that the owner would need to live in the other home for a period of time, but I am not certain.

It sounds like the owner would be the only one capable of taking the credit since - "You must reduce the basis of your home by the amount of any credits allowed."

Under no circumstance should you rely on this response. Get professional tax advice.