Illinois’s net metering landscape shifted on January 1, 2025, and the effects are still working their way through commercial solar project economics across the state. If you’re a CFO, facilities manager, or commercial property owner currently evaluating commercial solar savings in Illinois, the policy change is real, it affects your ROI model, and it needs to be part of every conversation you have with a developer before signing anything.
This post breaks down exactly what changed under Illinois NEM 2.0, what it means for projects in the 500 kW to 2 MW range, and why the updated policy actually strengthens the case for integrated energy planning rather than weakening it.
What Changed with ComEd Net Metering in 2025 (and Why It Matters Now)
Under the old net metering structure, commercial solar customers on ComEd’s grid received a one-to-one credit for every kilowatt-hour of excess electricity exported to the grid. That credit offset supply charges, delivery charges, taxes, and fees — the full retail rate. It was a straightforward financial equation.
As of January 1, 2025, that changed. The Illinois net metering 2025 changes, codified under the Climate and Equitable Jobs Act (CEJA), moved all new solar customers onto supply-only net metering in Illinois. Credits now apply to the supply portion of the bill only. Delivery charges and fixed fees are no longer offset by exported energy, and this applies to every system interconnected in ComEd and Ameren territories after December 31, 2024.
The ComEd net metering changes 2026 planning conversations need to reflect this reality. If you’re modeling a commercial project today, you’re modeling under NEM 2.0.
What Is Supply-Only Net Metering? How It Differs from Full Retail Credit
Here’s the practical difference. Under full retail net metering, if your system exported 10,000 kWh to the grid in a given month, you received credit against your entire bill, covering supply, delivery, and fixed charges. Every kilowatt-hour exported carried full retail value.
Under supply-only net metering in Illinois, that same 10,000 kWh export earns credit only against the supply portion of your bill. Delivery charges and fixed fees are still owed regardless of how much your system produces. Since supply typically represents roughly half to two-thirds of a commercial electric bill, the Illinois solar net metering credit rate in 2026 carries meaningfully less value than it did before the transition.
For large commercial facilities — manufacturing plants, cold storage operations, distribution centers — this matters. The financial model for commercial solar solutions in northern Illinois has to account for bill structure, not just generation volume.
Are Existing Commercial Solar Customers Grandfathered Under the Old Policy?
Yes, with conditions worth understanding. Grandfathered solar net metering in Illinois applies to commercial customers whose systems were installed, inspected, and had all required documentation submitted to ComEd by 5 p.m. on December 31, 2024. Those customers are locked into full retail net metering for the life of their system, defined as 30 years from the permission-to-operate date.
The risk worth knowing: grandfathered status can be lost. For ComEd customers, any modification requiring a new interconnection application, such as increasing AC system capacity, may move the system onto NEM 2.0 terms. If you’re managing an existing grandfathered system and considering a retrofit or expansion, that decision warrants careful review before moving forward.
How NEM 2.0 Changes the ROI Math for 500 kW to 2 MW Commercial Projects
The Illinois NEM 2.0 commercial solar shift doesn’t eliminate project ROI, but it does change where the value is concentrated. Under full retail net metering, exporting energy to the grid was nearly as valuable as consuming it onsite. Under supply-only terms, onsite consumption is significantly more valuable than export.
This reframes how commercial projects should be sized and structured. Self-consumption becomes the primary value driver, meaning systems should be modeled to maximize onsite load coverage rather than maximize export. Oversizing a system to push excess to the grid at supply-only rates erodes commercial solar ROI in Illinois 2026 projections.
Demand charge management also becomes more critical. For facilities with significant peak demand exposure, demand charge management through paired storage becomes a stronger ROI contributor than net metering credits were under the old policy. And payback period modeling requires utility-specific analysis. Generic national ROI calculators don’t reflect ComEd’s bill structure. Projects need to be evaluated against actual supply and delivery rate breakdowns, not industry averages.
This is why working with an experienced commercial solar developer in northern Illinois matters more now than it did two years ago.
The ComEd DG Rebate for Commercial Solar: Should You Accept It?
The ComEd DG rebate for commercial solar offers $300 per kilowatt DC for qualifying systems using smart inverters. On a 1 MW project, that’s $300,000 in upfront capital toward your commercial solar ROI in Illinois 2026 projections, and it’s a number worth taking seriously.
The tradeoff is straightforward. Accepting the rebate locks you into NEM 2.0 supply-only terms regardless of when your system was installed. For existing system owners who still hold grandfathered solar net metering status in Illinois, accepting the rebate means forfeiting that protection. For most new commercial projects moving forward, grandfathered status is no longer available anyway, so the rebate represents additional value with no meaningful downside.
How Battery Storage Offsets the Loss of Full Retail Net Metering Credits
This is where Illinois NEM 2.0 and integrated energy planning intersect most directly. The reduction in export credit value is largely recovered when storage is built into the project from the start.
Battery storage for commercial buildings allows facilities to capture excess solar generation and deploy it during peak demand periods rather than exporting it at supply-only rates. The result is a higher effective value per kilowatt-hour, reduced peak demand charges, and greater energy resilience across the facility.
For a 500 kW to 2 MW facility, the math typically works like this. Export credits that once carried full retail value now carry supply-only value. The gap between those two numbers is often smaller than the demand charge reduction achievable through well-designed storage dispatch.
A solar battery rebate in Illinois for commercial properties is also available alongside the DG rebate, making storage integration more financially accessible than it’s been before. Understanding peak demand charges explained is foundational to evaluating whether battery storage for a commercial building in Illinois makes sense for your facility.
NEM 2.0 didn’t make commercial solar less viable. It made integrated solar-plus-storage planning more financially logical than it was before.