Illinois Net Metering

For Illinois consumers, there has never been a better time to install a solar energy system or other renewable generator. If you generate your own electricity from a renewable source, it used to be very difficult to sell that power back to your utility. In 2008, however, legislation took effect that simplified the process considerably for Illinois consumers. If you own or operate a renewable electric generator, you may be able to interconnect to the electric company’s grid and get a credit for the excess electricity you produce.

Residential solar installations are the most common applications of Illinois net metering programs, but net metering can also apply to other forms of renewable energy installations as well. Read more about residential solar in our Introduction to Rooftop Solar.

Net Metering

Residential and commercial customers of ComEd, Ameren and MidAmerican can participate in “net metering.” This means that if you generate your own electricity using a renewable resource, you can get credits on your bill for those times when you generate more power than you use. Your utility will only charge you for the net amount of electricity you consume, plus any other fixed delivery charges.

What Type of Systems Qualify?

You must own or operate an on-site renewable electric generator of up to 2,000 kilowatts (kW) that is used at your home or business. While most participants in net metering will choose to generate electricity using a solar or wind system, other renewable systems also qualify.

Eligible renewable electric generators can be powered by:

  • Solar energy (photovoltaic, or “PV”);
  • Wind;
  • Dedicated crops grown for electricity generation;
  • Anaerobic digestion of livestock or food-processing waste;
  • Fuel cells or microturbines powered by renewable fuels; or
  • Hydroelectric energy.

How much will I be paid for the electricity I generate?

Illinois net metering law requires investor owned utilities (ComEd, Ameren, MidAmerican) to offer one-to-one net metering for renewable energy generation that is sized to offset the household’s energy usage. One-to-one net metering means that you will be credited for the electricity you send back to the grid at the same rate that you are charged for electricity. One kilowatt-hour sent to the grid offsets 1 kilowatt-hour used from the grid. This is the best type of net metering policy for consumers because it will lead to the highest level of savings.

In a given month, if you produce more electricity than you use, those excess net metering credits will rollover to the next month and can help offset future electricity usage. Any remaining credits will expire once per year, either in April or October, depending on which option you select. An April expiration date is best for solar installations as it gives you the most time to use built up credits from the previous summer. An October expiration date is best for wind installations because wind turbines produce more in the winter than in the summer, and October gives you the most time to use built up credits from the previous winter.

Different utilities set different parameters for net metering. To participate in net metering with ComEd, the system must be sized to offset up to 110% of the electricity you used over the previous 12 months. Anything larger than 110% would not qualify for net metering, and you would be credited for electricity sent back to the grid at a lower rate than you purchased the electricity.

Ameren and MidAmerican do not require you to size your renewable generation systems to match your usage. But remember, unused net metering credits will expire at the end of your annual period, so it is still economical to have your renewable energy system match the electricity demand of your household.

If you are a customer of a municipal utility or electric cooperative, you will need to contact it to see if they have a net metering program.

How do I apply for net metering?

Typically, the installer you’re working with will fill out the net metering application for you. We recommend confirming this with your installer. For more information, or to apply for net metering, contact your electric utility.

ComEd

Ameren

MidAmerican (Private Generation)

What If I'm with an Alternative Supplier?

Alternate suppliers are required to offer net metering and to provide net metering credits at the same rate they are charging you for electricity. Alternate suppliers are also required to have contact information specifically for net metering concerns.

While they are required to comply, alternate suppliers do not always meet these requirements. It can often be simpler to cancel with an alternate supplier and participate in net metering with your utility company. The utility companies have larger net metering departments than the suppliers, making it easier for them to address your net metering questions.

Any banked net metering credits (that have rolled over from a previous month) are only recognized by your current electricity supplier. If you switch suppliers you will lose any banked net metering credits with your current supplier. This is true whether your electricity is currently supplied by your utility company or by a third party supplier.

Can I Participate in Real Time Pricing and Net Metering?

ComEd and Ameren customers with rooftop solar installations can still participate in their utility’s real-time pricing program (“Hourly Pricing” for ComEd, “Power Smart Pricing” for Ameren). If you pay a “time-of-use” rate, your net metering credits will also reflect the time-of-use rate. Solar customers may benefit from real-time pricing, which charges participants a market rate that can change hourly. That’s because they can pull electricity from their panels during hot summer afternoons and avoid paying peak prices for electricity.

There isn’t enough data yet on whether it’s best to be on real time pricing with net metering. We recommend trying real time pricing if you are interested but remember that you aren’t guaranteed to save money. That means it’s important to check your monthly real time pricing results (emailed to you every month) to make sure you’re saving through the program.

Note: If you have an electric vehicle, adding real-time pricing makes even more sense. Charge your vehicle at night, when prices are typically lower, and your net metering credits will cover more of your car-charging expenses.

What is Interconnection?

When you apply for net metering, you will also have to apply for interconnection. Interconnection is permission to connect your renewable generator to the electric utility’s grid. If you are installing a residential solar system, your solar installer will typically fill out both the net metering and interconnection applications on your behalf. If you are installing a different type of renewable generator, ask the company you are working with if they will handle the interconnection and net metering applications.

What about interconnection for larger systems?

Net metering and interconnection both become more complicated if you are trying to install a large system. By large we mean a system between 10 kilowatts (kW) and 2,000 kW. For context, the average residential solar installation in Illinois is 7 kW.

With larger systems, the utility may need to conduct a study to see if the grid in your area can accommodate the electricity your system is expected to export to the grid. For some large systems, they may determine that the grid cannot accommodate the new generation. In this case you would be required to pay for the grid upgrades necessary to accommodate your system’s electricity generation.

If you are thinking of installing a larger renewable energy generator we recommend involving your utility company from the early planning stages, so that you are not surprised by any of the associated costs.

For more information on interconnecting larger systems see the Administrative Code on Interconnection of Distributed Generation Facilities.