Net metering is a foundational policy for distributed solar in the United States. By Wednesday, 45 states had implemented programs under which utilities must credit solar PV system owners for the electricity they produce at the retail rate.
A Thursday decision by the Mississippi Public Service Commission (MPSC) (official rule here) made the state the 46th to implement net metering. However, despite the findings of a study ordered by the commission which found that net-metered solar produces value higher than the retail rate, Mississippi decided to credit excess electricity produced by its customers at the wholesale electricity rate plus US$0.025 per kilowatt-hour (kWh). The portion of excess generation will be calculated monthly.
Under net metering excess generation from month to month is typically but not always credited at the retail rate. In this case, the MPSC chose to use the method advocated by utilities. Additionally, the first 1,000 customers to enroll in the program will receive an extra $0.02/KWh for the generation they produce in excess of use.
Residential solar projects up to 20 kW in capacity will be eligible for net metering, as will be non-residential projects up to 2 MW. The aggregate capacity eligible to participate is limited to 3% of total system peak demand. This system-wide cap is lower than that recently reached by some Massachusetts utilities, but higher than the 0.5% cap recently reached by Louisiana’s largest utility.
This new rule will apply to customers of Entergy Mississippi and Mississippi Power Company, and cooperatives will have nine months to propose their own rules or adopt the commission’s rules. The Tennessee Valley Authority, which supplies power to the northern part of the state, has its own program and is not subject to the new rule.
Solar advocates were disappointed by the policy.
"It’s clear that the rules are unnecessarily complex and will be a burden for a simple ratepayer to understand the value of their own home grown solar energy," Gulf States Renewable Energy Industries Association (GSREIA) President Jeff Cantin told pv magazine.
"Although this is incremental progress from where Mississippi was a week ago, if the state is looking to encourage the jobs, societal benefits , and economic windfall of customer owned solar energy, they still have a ways to go. If they are looking to keep their utilities content, they have certainly achieved it."
The commission intends to conduct a cost-benefit analysis three years from now, and to re-open the net metering ruling in five years’ time.
Update: This article was modified at 4:17 PM Eastern Time (U.S.) on December 4 to replace a quote in the AP by Jeff Cantin with a longer quote sent directly to pv magazine, and additionally modified at 4:28 PM to clarify that the wholesale plus $0.02 credit only applies to excess generation, and to make changes to how the policy is characterized.