RSMo 386.890 Explained: Missouri's Net Metering and Easy Connection Act.

This section shall be known and may be cited as the Net Metering and Easy Connection Act. RSMo 386.890.1

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That single sentence opens a 13-subsection statute that has shaped Missouri residential solar economics for nearly two decades. The law was passed in 2007 with the goal of standardizing how Missouri utilities handle small-scale renewable energy systems on customer premises. Before this statute, each utility could refuse interconnection or impose punitive fees on solar customers; after enactment, the floor for treatment of customer-generators was set in state law.

For Missouri homeowners considering solar in 2026, the parts of RSMo 386.890 that matter most are the system-size cap (100 kW), the compensation structure (1:1 retail rate), the simplified process for systems 10 kW and under, and the requirement that all retail electric suppliers in Missouri offer net metering on a first-come, first-served basis. Each of these provisions has direct economic implications that shape what a solar system on a Missouri home is worth over its 25-year lifespan.

1. Net metering must be offered

   Every retail electric supplier shall make net metering available to customer-generators on a first-come, first-served basis. Utilities cannot refuse to offer net metering until the cumulative net metering capacity exceeds 5 percent of the utility's previous-year peak load.

2. 1:1 retail rate compensation

   Excess generation during a billing period is credited at the same retail rate the utility charges. No separate "wholesale" rate, no reduction for distribution charges. This is notably better than Kansas (partial rate) and most California customers under NEM 3.0.

3. 100 kW maximum system size

   Customer-generator systems up to 100 kW capacity qualify for net metering. Most residential homes need 5 to 12 kW, so the cap is rarely binding for homes. For comparison, Kansas caps residential at 15 kW under K.S.A. 66-1263.

4. Free interconnection for systems 10 kW and under

   Systems 10 kW and under cannot be required to install additional controls, perform additional tests, pay for additional distribution equipment, or carry additional liability insurance beyond what other customers in the same rate class face. Application process uses a simplified all-in-one document.

5. Excess credits roll forward, true-up annually

   If your solar produces more than you consume in a billing period, the excess credits roll forward to the next month at full retail rate. At your annual true-up date set by the utility, any remaining excess credits are paid at the lower avoided fuel cost rate.

6. Standard tariff treatment

   Net metering customers must be offered a tariff or contract that is identical in electrical energy rates, rate structure, and monthly charges to the contract or tariff that other customers in the same rate class face. No solar-specific surcharges, no customer-generator demand charges.

7. Industry-standard safety codes

   Customer-generator systems must meet IEEE, NEC (National Electrical Code), NESC (National Electrical Safety Code), and UL (Underwriters Laboratories) standards. Utilities can require a manual disconnect switch in immediate proximity to the meter, but cannot impose proprietary or non-standard equipment requirements.

The 100 kW vs 15 kW residential cap is the headline difference. In practice, the Kansas cap is binding for some larger homes (5,000+ sq ft with electric heat, pool, EV charging), while the Missouri cap rarely matters for residential. The 1:1 retail rate vs partial rate is the second key difference: Kansas customers see lower-value credits when their solar produces excess.

For homeowners in border cities (Kansas City MO vs Kansas City KS, for example), the choice of which side of the state line to live on actually affects long-term solar economics. A typical 8 kW system on a Missouri home will typically generate $5,000-10,000 more in lifetime value than the same system on a Kansas home, primarily due to the better excess-credit treatment.