Net Metering

Note: The Climate and Equitable Jobs Act (Illinois Public Act 102-0662) removed the 5% aggregate cap on net metering and replaced it with a threshold date of December 31, 2024, or when utility tariffs setting new compensation values are approved, whichever is later. This law also raised the individual system size cap to 5 MW, although systems must still be sized to meet on-site electricity needs.

Note: The Future Energy Jobs Act (Illinois Public Act 99-0906) did not change Illinois' basic net metering rules; the 5% aggregate cap remained in place and a new compensation process will be developed when the cap is reached (a net billing process is the default). Community solar and meter aggregation were made eligible for net metering under the terms of the legislation; the language in previous law allowing utilities to "consider" whether to allow net metering to meter aggregation and community solar customers was removed and replaced with specific terms under which net metering must be allowed.

Illinois enacted S.B. 680 in August 2007, requiring investor-owned utilities and alternative retail electric suppliers in Illinois to offer net metering. Municipal utilities and electric cooperatives are not required to offer net metering.

For customers in competitive classes as of July 1, 2011, the law prescribes a dual metering and bill crediting system, which does not meet the definition of net metering as the term is generally defined. Customers in non-competitive classes as of July 1, 2011, are eligible for net metering; this includes all residential customers and non-residential customers with electric loads of up to 100 kW in the ComEd service territory and up to 150 kW in the Ameren utilities service territory. 

Eligible Technologies 

In Illinois, net metering is available to electric customers that generate electricity using solar energy, wind energy, dedicated energy crops, anaerobic digestion of livestock or food processing waste, hydropower, fuel cells and microturbines powered by renewable fuels, agricultural residues, untreated and unadulterated wood waste, landscape trimmings, and livestock manure. 

System Size

Systems up to 5 megawatts (MW) in capacity that are intended primarily to offset the customer's own electrical requirements are eligible for net metering. 

Aggregate Cap

Each investor-owned utility and retail supplier must provide net metering and dual metering until the load of its net-metering customers and dual-metering customers equals 5% of the total peak demand supplied by the utility during the previous year. 

Metering Equipment

For eligible customers whose electric service has not been declared competitive as of July 1, 2011, and whose electric delivery service is provided and measured on a kilowatt-hour (kWh) basis and electric supply service is not provided based on hourly pricing, net metering is accomplished through use of a single, bi-directional meter. The electricity provider must arrange for the local electric utility or a meter service provider to install and maintain a new revenue meter at the electricity provider's expense. 

For eligible customers whose electric service has not been declared competitive as of July 1, 2011 and whose electric delivery service is provided and measured on a kilowatt (kW) demand basis and electric supply service is not provided based on hourly pricing, net metering is accomplished through the use of a dual channel meter. Customers must pay for the costs of installing necessary metering equipment. 

For all other eligible customers, the electricity provider may arrange for the local electric utility or a meter service provider to install and maintain metering equipment capable of measuring the flow of electricity both into and out of the customer's facility at the same rate and ratio, typically through the use of a dual channel meter. If the eligible customer's existing electric revenue meter does not meet this requirement, then the costs of installing the equipment is paid for by the customer.

Net Excess Generation 

For eligible customers whose electric service has not been declared competitive as of July 1, 2011, and whose electric delivery service is provided and measured on a kWh basis and electric supply service is not provided based on hourly pricing, any net excess generation (NEG) during a billing period is carried over as a kWh credit (at the retail rate) to the following billing period. At the end of an annualized period, any remaining NEG credits in the customer's account expire. Customers may select an annualized period that ends with last day of either their April or October billing period for this purpose.

For eligible customers whose electric service has not been declared competitive as of July 1, 2011, and whose electric delivery service is provided and measured on a kWh basis and electric supply service is provided based on hourly pricing, any NEG during a billing period is carried over as a kWh credit that consists of an energy credit and a delivery service credit. The energy credit is valued at the same price per kWh as the electric service provider would charge for kWh energy sales during that same hourly period. The delivery credit is equal to the net kWh produced in such hourly period times a credit that reflects all kWh-based charges in the customer's electric service rate, excluding energy charges.

For eligible customers whose electric service has not been declared competitive as of July 1, 2011, and whose electric delivery service is provided and measured on a kW demand basis and electric supply service is not provided based on hourly pricing, any NEG during a billing period is carried over as a 1:1 kWh credit that reflects the kWh-based charges in the customer's electric service rate.

For all other eligible customers, any NEG during a billing period is compensated at the electricity provider's avoided cost of electricity supply over the monthly period. 

Renewable Energy Credits

All net metering customers (and dual-metering customers) hold ownership and title to all renewable energy credits (RECs) and greenhouse-gas credits associated with customer generation.

Meter Aggregation and Community Net Metering

The Illinois net metering statute requires electricity providers to “consider” whether to allow meter aggregation for the purpose of net metering. For the purposes of this section, “meter aggregation” would allow multiple customers to effectively net meter their utility bills on a pro-rata basis for shared renewable energy facilities. (Note: This type of arrangement is called "virtual net metering" or "neighborhood net metering" in other states.) Electric providers may choose to offer meter aggregation for community-owned wind, biomass, solar, or methane digesters, or other situations where multiple individual customers are served by the same renewable generating facility. No electric provider has elected to do so as of November 2015. Legislation passed in December 2016 changed this rule; electricity providers now must allow net metering for the customers mentioned above provided the facility has a nameplate capacity of no more than 5,000 kW.

Certification Requirement

All net-metered systems are required to be installed by a certified contractor.

Non-discriminatory Rates Requirement

An electricity provider is required to provide electric service to eligible customers who utilize net metering at non-discriminatory rates that are identical, with respect to rate structure, retail rate components, and any monthly charges, to the rates that the customer would be charged if not a net metering customer. An electricity provider is not permitted to charge net metering customers any fee or charge or require additional equipment, insurance, or any other requirements not specifically authorized by interconnection standards authorized by the ICC, unless the fee, charge, or other requirement would apply to other similarly situated customers who are not net metering customers.