Sizing your system properly to produce the amount of energy you are needing is important. Reviewing your energy statements over the past 12 months will help you determine your power needs. Commercial installations typically range from 50 kW to 300 kW and larger. Your solar installer will help you determine the proper system size.

Installing solar typically isn't a DIY project. If you are unsure what questions to ask, please review this checklist – Questions to Ask Your Solar Provider (PDF). To find an installer, please visit www.moseia.com and review their installer list. We recommend getting three estimates for comparison.

Once you have selected a solar installer, they can complete an application for you based on your system. You and your installer can also view our FAQ's to better understand size requirements. Ameren Missouri will review the submitted application and approve or reply within 30 days (systems 10kW and below) or 90 days (11 kW and larger systems). After your installer completes the installation, they will return sections E/F of the application and get an inspection if your municipality requires it. Ameren Missouri will then order a bi-directional meter if applicable. Current bi-directional meter costs are $226 for a single phase and $169 for three phase. Your installer will guide you through the final stages before you start enjoying the benefit of solar energy.

If a customer either chooses not to apply for net metering or their system size is above 100 kW, they will need to apply for an agreement called a Qualifying Facility agreement. This agreement requires the customer to make one of the following choices.

• No excess energy will be purchased by Ameren Missouri: The metering equipment necessary to measure the energy from the customer to Ameren Missouri will not be installed. Any energy delivered from the customer to Ameren Missouri will not be measured and the customer will not be compensated for this energy.
• Excess energy purchases by Ameren Missouri –Metering equipment to measure the delivery of energy from Customer to Company– will be installed. Any energy delivered by Customer to Company will be purchased by Company in accordance with Company’s Electric Power Purchases From Qualifying Facilities tariff, and Customer will be assessed the monthly Customer Charge specified in Section 1.c. (in addition to the Customer Charge applicable under Company’s standard rates for retail electric service). Energy purchased by Company will be at the rates specified in Section 1.a. Non-Time-Differentiated rate unless the Customer has elected to purchase energy under one of Company’s Time-of-Day rates in which case the energy purchased by Company will be at the rates specified in Section 1.b. Time-Differentiated rate.

A one line diagram and spec sheets for the equipment are required with the Qualifying Facility application (PDF) for our engineering staff to review.

	Net Metering	Qualifying Facility
Maximum System Size	Maximum size for net metering for residential or commercial installations is 100 kW or enough to offset the full load of the facility.	Maximum size for a Qualifying Facility is 500 kW. For larger systems please contact Applied Energy Group at amerensolar@appliedenergygroup.com
Online Application	Yes	Yes for systems up to 500 kW. For larger systems please email amerensolar@appliedenergygroup.com
Billing	The customer is billed monthly for the net difference in what they received from Ameren Missouri and what they delivered to Ameren Missouri. If more is delivered than received, the customer will receive a credit on their energy statement.	The customer chooses one of the following. (1) No excess energy will be purchased and no metering equipment will be installed. Any energy delivered to Ameren Missouri will not be measured and the customer will not be compensated for this energy. (2) A bi-directional meter is installed and any energy delivered by the customer to Ameren Missouri will be purchased at the tariff rate. *No netting occurs under a QF agreement. Any energy that flows to Ameren Missouri is purchased by Ameren Missouri.
Bi-directional meter	There is a one-time charge on the customer's energy statement.	If the customer has chosen sales of excess production to Ameren Missouri, a bi-directional meter charge is billed monthly on the energy statement.

As of December 31st, 2023, Ameren Missouri no longer has a solar rebate program. However, new and expanding solar installations are required to go through the application process.

View details regarding Ameren Missouri Solar Rebates (PDF).

For customers who had their system installed, submitted Sections E and F of the application, and submitted an inspection (if your municipality requires it) before December 31st, 2023, you are eligible for the solar rebate. Please check Solar Credit Project Status (PDF) for your rebate status. Unfortunately, if these requirements were not met prior to December 31st, 2023, your system is not eligible for the solar rebate.

The language of Net Metering statute is specific regarding how net metering is to be calculated and when it is to be available. Ameren Missouri's "optional" time-of-use rates do not fall within those criteria. As a result, net metering IS available with both the residential Anytime Saver rate and the Evening/Morning Saver rate but is not available with Overnight Saver, Smart Saver or Ultimate Saver rates. As part of the application process your Ameren account rate will be verified to ensure it meets the Net Metering or Qualifying Facility requirements.

For most customers, utilizing the net metering option would be more beneficial. However, if you would like to keep the optional time of use rates then you will need to submit a new qualifying facility application, which does not give you the opportunity to sell your excess generated energy to Ameren Missouri.

It is a meter that can measure the flow of electricity in two ways. It measures how much energy comes from Ameren (kWh delivered) when the solar system is not producing electricity, like at night. It also measures the difference between what is generated by the solar system and the customers load. It does NOT measure the solar systems total production. As the system is producing electricity, this energy is used to meet the customer's electric requirements. If more energy is produced than used, this electricity is fed to the utility. This is typically during daylight hours. The bi-directional meter records this. At night when solar is not producing, the customer is using electricity from Ameren. If the customer produces more than they use they will see a credit on their energy statement. If the customer uses more than they produce, they are charged for this power. Net metering is for customers with solar systems sized 100 kW and less.

Your new Smart Meter will have the same capabilities as your former bi-directional meter.

A bi-directional meter (PDF) is a meter that can measure the flow of electricity in two directions - flowing from Ameren Missouri's power grid to a customer and flowing from a customer's home or business back to the power grid.

Your energy statement will include a few new items. You will now see how much energy you are sending to Ameren Missouri-Customer kWh to Utility. You will also see how much you are purchasing from Ameren Missouri-Net Billable kWh. Please view a sample bill (PDF).

Please note the following regarding net metering:

• If your solar system produces more energy than you use, you will receive a credit on your energy statement at the net metering rate of:
  • SUMMER (June through September) 3.84 cents per kWh
  • WINTER (October through May) 3.39 cents per kWh
• If your system produces more than you consume you WILL NOT have a zero bill. All other regular monthly charges will still apply.
• Community Solar Customers: Please contact Ameren to cancel your community solar subscription. Ameren will not be able to switch your billing to net metering if you are still subscribed to the community solar program.
• Budget Billing Customers: It is advised to reevaluate your budget billing when you install solar. Keeping budget billing may increase your bill rather than reduce it if your solar panels are working to reduce your electric usage.

Ameren does not install solar or recommend solar installers. Please visit www.MOSEIA.com for a list of solar installers in Missouri or see a list of installers (PDF) who have completed solar installations in the Ameren Missouri service territory in the past year.

Ameren Missouri must review your renewable project before operation/installation to determine whether the renewable system could adversely affect the safety, reliability or quality of the local electric utility service. See the Ameren Service Manual (PDF) for technical requirements reference. Also see recent Residential Meter Socket Change Information (PDF).

Sample one lines (PDF)

Solar panels absorb energy from the sun and convert it to direct current (DC) electricity. Most homes and businesses run on alternating current (AC) electricity. The DC electricity is passed through an inverter to convert it to AC electricity, which is then used or sent back to the grid.

The maximum allowable system size in kW DC is calculated based on your past 12 month usage. If a customer account has a single revenue meter, please see the example below to calculate maximum allowable.

Most recent 12 billing month load kWh/(8,760 hrs. x 15.6% Capacity Factor) = Maximum Allowable Nameplate Capacity in kW DC

Example:

Previous 12 month load = 13,512 kWh

• Hours in a year = 8,760 hours
• Solar Capacity Factor = 15.6% (based on DOE PV Watts)
• Maximum Allowable Nameplate Capacity = 13,512/(8,760 x 0.156) = 9.887 kW

*Please note, this formula should be used only as an estimate. Upon receipt of a Net Metering Application, Ameren Missouri will evaluate the account and calculate the maximum based on the most recent 12 month usage.

For net metering, installation agreements cannot exceed 100 kW.

For Residential new construction, please contact Ameren Renewables with your new home’s square footage (living space only – minus garage and basement even if finished) to obtain your maximum solar nameplate capacity.

For Commercial new construction, please complete the Commercial Load Sheet (PDF) and email to Ameren Renewables to obtain your maximum solar nameplate capacity.

If adding panels to an existing solar system, the solar system must still be within the maximum allowable nameplate capacity.

Maximum Allowable Nameplate Capacity = 13,512/(8,760 x 0.156) = 9.887 kW

*Please note, this formula should be used only as an estimate. Upon receipt of a Net Metering Application, Ameren Missouri will evaluate the account and calculate the maximum based on the most recent 12 month usage.

Yes, you can self-install solar. Ameren Missouri recommends contacting an installer as they know our requirements for the interconnection application process.

For all design/construction requirements please reference the Ameren Electric Service Manual. Click here (PDF) to download.