Regulatory & Program
Illinois Shines Clarifies REC Calculations Based on AC System Size and Output
Illinois Shines · Aug 7
What happened
Illinois Shines requires Renewable Energy Credit quantity calculations to be based on AC system sizes and output. The program portal automatically calculates capacity factors using PVWatts Version 8, but Approved Vendors may submit alternative capacity factors that exceed default values. Custom calculations that fall outside established market norms may face additional program review.
Why it matters
Developers and Approved Vendors adjusting capacity factors above PVWatts defaults must ensure their methodology strictly uses AC capacity and production metrics. Asset owners should monitor submission portal inputs, as non-standard production assumptions could delay project approval or REC contract execution.
Original source
Illinois Shines
Program REC Quantity Calculations are calculated using the AC system sizes and output