Sounds like there was miscommunication between you and whatever CPA you talked with. First, you need to understand a few terms.
A Tax Credit is a dollar for dollar reduction in your tax liability. So if your tax liability before the credit is $10,000, the credit reduces your tax liability dollar for dollar to $3000.
A Tax Deduction reduces the amount of income you pay taxes on. So if you have $100,000 of income taxed at 10%, that means your tax liability is $10,000. But if you have a $10,000 tax deduction, that reduces your taxable income from $100,000 to $90,000. Then your tax liability would be $9000.
With that said, what you get for your solar panels is a tax credit. Therefore, if you get a $7000 tax credit, and your tax liability for 2019 before the credit is $5000, that means you pay no taxes at all for 2019. The remaining $2000 of credit is carried over to next year.
For your business income, you *WILL* pay the self-employment tax which is 15.3% of your taxable business income. The self-employment tax is basically the employer side of your social security and medicare. So in a sense, you are paying your future self for your social security pay and medicare coverage you will have when you reach retirement age and apply for Social Security and Medicare.
So the bottom line is, with your SCH C income you "WILL" pay taxes - buy only the employer side of the self-employment tax.
