I think it may come down to the definition of "rebate" and in particular, "Green Energy Rebate" that you reference. I believe that refers to the "instant" rebates that are supposed to be part of the Inflation Reduction Act for low-to-moderate income households (but as far as I know, aren't yet active, at least in California), separate from the tax credits that are not income-based. Those rebates happen at purchase, so are considered a reduction in purchase price, as you note. In my case, the city wanted to incentivize installation of heat pumps, so offered residents a monetary "rebate" to do so, from city funds. It seems this isn't really considered a rebate by the IRS: several months after getting our money, the city sent this communication (along with a request for a W2): "Our finance department recently discovered that all rebates over $600 are considered taxable income by the IRS."
So I'm pretty sure that at least for now, the IRS considers this taxable income. I'm just wondering/hoping that the state sees it differently!
