ComEd - Interconnection Guidelines (Illinois)

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Last modified on May 23, 2011.

Rules Regulations Policies Program

Place Illinois

Name ComEd - Interconnection Guidelines
Incentive Type Interconnection
Applicable Sector Commercial, Industrial, Residential
Eligible Technologies Solar Thermal Electric, Photovoltaics, Landfill Gas, Wind, Biomass, Hydroelectric, Geothermal Electric, Fuel Cells, Municipal Solid Waste, CHP/Cogeneration, Microturbines, Other Distributed Generation Technologies
Active Incentive No

Implementing Sector Utility
Energy Category Renewable Energy Incentive Programs

Applicable Utilities Yes

External Disconnect Switch Yes (for systems < 40 kW)

Insurance Requirements No

Net Metering Required Yes

Standard Agreement Yes

System Capacity Limit No size limit for DG rules; 25 kW or 40 kW for net-metered systems /

No limit on installed capacity under DG rules

Date added to DSIRE 2003-06-18
Last DSIRE Review 2008-04-01

References DSIRE[1]


Illinois does not have statewide interconnection standards in place for distributed generation (DG), but the Illinois Commerce Commission (ICC) is now in the process of developing rules. Individual utility rules are in place to address the interconnection of small-scale DG. The state's largest electric utility, ComEd, has interconnection guidelines for net metering and DG.

ComEd's DG rules divide systems into three capacity categories: 25 kVA to 2.5 MVA; 2.5 MVA to 10 MVA; and systems larger than 10 MVA. In general, customer-generators are responsible for all interconnection study charges, and systems must be an eligible qualifying facility (QF) under the Public Utility Regulatory Policies Act of 1978 (PURPA) to receive any payment for power sent to utility. Significantly, there is an exception for net-metered photovoltaic (PV) and wind-energy systems with a capacity less than 40 kilowatts (kW); these systems are not required to file to become a QF. All small systems up to 25 kVA (and net-metered PV and wind systems up to 40 kVA) require a manual, lockable disconnect switch accessible to the utility. However, special interconnection relays are not required.

The difference in interconnection requirements for systems in the three capacity categories involves specific relay standards. Procedurally, all systems require a series of reviews by ComEd engineering staff. ComEd does not allow interconnection within "The Loop," an area network that serves the heart of downtown Chicago. As a result, DG systems that could be used as back-up generation for downtown high rises are unable to interconnect.

Incentive Contact

Contact Name Maryl Freestone
Department Exelon Corporation
Division ComEd Energy
Address ESO Tech. Services, 2nd Fl
Address 2 Three Lincoln Centre
Place Oakbrook Terrace, Illinois
Zip/Postal Code 60181-4260
Phone (800) 825-5436


  • Incentive and policy data are reviewed and approved by the N.C. Solar Center's DSIRE project staff.[1]


  1. 1.0 1.1  "Database of State Incentives for Renewables and Efficiency (DSIRE)"