How to model the Illinois smart solar billing

Summary:

Beginning January 1, 2025, Illinois is replacing full retail Net Metering with a new solar compensation model called Smart Solar Billing. This shift supports the state’s goal of reducing peak electricity demand and promoting battery storage and grid participation through Virtual Power Plants (VPPs).

Key changes include:

• Export credits will apply only to the generation portion of energy bills.

• Lifetime rollover of unused export credits (no expiration).

• Continued availability of generous upfront rebates for solar and storage systems.

• OpenSolar now fully supports Smart Solar Billing through updated tariffs and accurate compensation modeling for major utilities.

Policy Transition Overview:

Effective January 1, 2025, Illinois will phase out full retail Net Metering and move to Smart Solar Billing to:

• Lower grid stress during peak hours

• Reduce electricity costs

• Encourage use of behind-the-meter battery systems and VPP participation

Transition from Net Metering to Smart Solar Billing:

• Legacy Customers: Retain full Net Metering benefits for the lifetime of their existing systems.

• New Installations: Exported solar energy credited only against generation charges.

• Export Credit Rollover: Credits never expire and carry over year-to-year.

Maximizing Savings: Incentives and Rebates:

For the upfront rebates, you can add and manually create them by heading to Control > Others > Incentives > + Add Incentive. 

Both the Battery Rebate and the Distributed Generation Rebate are Sized Based Incentives worth 300$ per kWh of the battery nameplate capacity and 300$ per kW of PV system DC Capacity.

Compensation Set up in OpenSolar:

• Updated Tariffs for Ameren Illinois, ComEd, and MidAmerican now include (Smart Solar Billing) suffix.

• Solar Compensation Section set to Net Billing with Credit Carryover.

• "Apply NEM Modified Export Rates" is enabled to ensure generation-only crediting.