Interconnection Guidelines

Missouri enacted legislation in June 2007 requiring all electric utilities—investor-owned utilities, municipal utilities, and electric cooperatives—to offer net metering to customers that generate electricity using wind energy, solar-thermal energy, hydroelectric energy, photovoltaics (PV), fuel cells using hydrogen produced by one of the aforementioned resources, and other sources of energy certified as renewable by the Missouri Department of Natural Resources.

The Missouri Public Service Commission (PSC) adopted administrative rules for investor-owned utilities that included simplified interconnection standards, and electric cooperatives and municipal utilities adopted their own rules, including an all-in-one document that includes a simple interconnection request, simple procedures, and a brief set of terms and conditions. 

Systems must meet all applicable safety, performance, interconnection and reliability standards established by any local code authorities, the National Electrical Code (NEC), the National Electrical Safety Code (NESC), the Institute of Electrical and Electronics Engineers (IEEE), and Underwriters Laboratories (UL) for distributed generation. Utilities may require customers to provide a switch, circuit breaker, fuse or other easily accessible device or feature that allows the utility to manually disconnect the system. 

System Capacity Requirements

Systems must be intended primarily to offset part or all of a customer’s own electrical energy requirements, have a capacity up to 100 kilowatts (kW), and be located on a facility owned, operated, leased or otherwise controlled by the customer.

Process

Utilities must offer a net-metering tariff or contract that is identical in electrical energy rates, rate structure, and monthly charges to the contract or tariff that the customer would be assigned if the customer were not an eligible customer-generator. Utilities may not charge the customer any additional standby, capacity, interconnection, or other fee or charge that would not otherwise be charged if the customer were not an eligible customer-generator. 

Applications for interconnection must be accompanied by a plan for the customer’s system, including a wiring diagram and specifications for the generating unit. Utilities must review and respond to the customer within 30 days for systems up to 10 kW, and within 90 days for systems greater than 10 kW. Prior to interconnection, a customer must furnish the utility with certification from a qualified professional electrician or engineer that the installation complies with the established safety and operating requirements. 

In June 2009 the PSC reduced the minimum liability insurance requirement for systems larger than 10 kW to $100,000 and eliminated the insurance requirement for systems of 10 kW and smaller. Insurance requirements may be met with an additional insurance policy or an endorsement on an existing policy.