I agree with @NCperson. I too don't think you have a "business" as the IRS defines it. Credit rebates against your utility bill are not usually considered taxable income. Instead, they're considered discounts.
I think the situation would be different if the utility paid you cash, instead of giving you rebates on your bill.
Does the utility company issue you a 1099 at year's end?
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
