Below is an overview of the Illinois SREC and a description on how to model it in Aurora. For more questions, please reference the Illinois official website here:
The Illinois Power Agency implemented a long-term renewable resources plan, part of which provides SRECs for customers who generate solar energy.
The document titled “Final 2021 Plan” below provides information pertaining to the Renewable Energy Credit (REC) program.
Final 2021 Plan
Notably, for systems of 25 kW AC or less, the RECs are paid up front (p.110), with the value determined based on the size of the system. There is a specific formula for the number of RECs expected to be generated by a PV system (p.131), where
#RECs = # kW * 0.1642 / 1000 kW/MW * 8760 hours/year* 15 years
The kW size of the system is determined by the nameplate size of the inverters. The 16.42% value is a capacity factor for fixed-mount systems. A system with an inverter capacity of 5 kW would be expected to produce about 108 RECs over the system lifetime.
The value of a REC is determined by the system’s application date, with earlier systems receiving a higher value per REC. The values are listed on p.105, with a value of $85.10/REC for Group A and $72.97/REC in Group B for Block 1.
Modeling in Aurora:
If we plug the $/REC value into the #REC/#W value, we find that the upfront RECs can be modeled as a System Size (AC W) grant with a value of:
- $1.8361/W AC for Group A Block 1
- $1.5744/W AC for Group B Block 1
These are pre-modeled in Aurora. Users can modify the values for systems larger than 10 kW, and once Block 1 is filled up the values will be reduced.