TurboTax's handling of the solar credit is needlessly confusing.
1. If you haven't already, you must complete Schedule EC yourself. You can get a copy of the form from Mass DOR: http://www.mass.gov/dor/docs/dor/forms/inctax16/addl/sch-ec.pdf
2. You enter the credit amount on the MA Credits screen as a "Business related non-refundable credit" - ignore the fact that you may not be a business.
3. Select the "Solar and Wind Energy Credit". Just enter the credit amounts - ignore the fields that don't apply to you.TurboTax should generate Schedule CMS for you. You won't be able to e-file, as you need to send in the paper Schedule EC with your tax return.