Taxpayer has paid all the cost of Solar Panel Installation on Main residence - construction has started however may not be finalized by December 31st.  

Does the individual homeowner qualify for the credit under the "Commence Construction" under the 5% safe harbor given that major project cost were incurred and paid in 2020 -

Or since it's for a residential project, in order to qualify for the ITC during a specific tax year the project must be “placed in service” by December 31 of that year and the equipment is considered “placed in service” once it has been fully installed and is capable of being used by the owner for its “specifically assigned function.”