The Colorado tax credit is refundable whether one has taxes or not. The Federal tax credit of $7,500 would require 80K in income to be taken which also would result in income taxable of $2,400 additional taxes to Colorado, unless that was already the amount of income the individual living on 25K per year was going to take. You only get that income tax credit when you file your taxes and show you owe at least that much before other taxes and credits (non refundable).
IF one was on ACA then the tax credit loss in going from 25K to 80K of income for a family of 3 with two parents 37 years old and one child is $6,000 in lost tax credits for ACA a family of 3 would only pay $42 per month for ACA with 25K of income and $9,200 in lost subsidies to the deductible for a silver plan. So you would lose $15,200 in credits for ACA to get $13,500 in Green environmental tax credits in the year you did this.
But if you were already spending far more than 25K per year and instead were paying over 100K per year, and just pretending to live on 25 K per year, these tax credits on the Nissan Leaf make this an incredibly good deal and an interesting blog post.
Now the interesting part is for a family of 3 25K of income per year is tax free from federal taxes so the income tax saved would not be a real savings, as if you could live on 25K you could go another 33 years to age 70 without ever paying taxes. And Colorado uses federal tax income exemptions and deductions to decide on income tax so at 25K you pay no state taxes either.
Therefore the marginal rates as you add taxes from ACA, federal and Colorado as you go forward are very high indeed -with out tax credits you would pay $7,300 in Federal taxes $2,400 in state taxes and $6000 in ACA tax credits for the additional 55K of income (not even counting the lost $9,200 deductible help) for a 28.5% effective tax rate and if you have medical claims the total potential loss is $27,900 or an effective tax rate of 47 percent.