Interconnection Standards

Summary

In December 2015, the Mississippi Public Service Commission (PSC) established net metering in the State accompanied by interconnection standards for distributed generator facilities. 

Eligibility

The standards apply to all the investor-owned utilities in Mississippi under the jurisdiction of the PSC. The cooperatives are required to file a net metering program and interconnection standard that is consistent with the rules set forward by the PSC. Cooperatives that participate in the TVA-sponsored net metering program are exempt from the rule. Interconnection request applications will be made available on the electric utility’s website. 

All the distributed generation facilities must be capable of being isolated from the electric utility. Level 2 and Level 3 systems require a lockable, visible-break isolation device. 

All the equipment used for interconnection must comply with IEEE 1547 Standard. IEEE 1547.2 standard can be used as a guide (but not a requirement) to detail and illustrate the interconnection protection requirements that are provided in IEEE 1547. 

Interconnection levels

The interconnection requests are categorized into three levels of review based on capacity. 

Level 1 interconnection review can be used for facilities that have nameplate capacity up to 20 kW, that are be inverter based, and have certified interconnection equipment. The electric utility must respond within 10 business days after submission of the application providing the status of the application. The utility then has 15 days after completion of the application to approve or deny the interconnection request. If the facility is not approved under Level 1 review, then the applicant may submit a new interconnection request under Level 2 or Level 3 process. The electric utility may not charge any fees for level 1 interconnection process. 

Level 2 interconnection review is used for facilities that have a nameplate capacity of up to 2MW. The total aggregated capacity of the generators on the circuit on which the facility is being interconnected must be less than 2 MW. The electric utility must respond within 10 days after the application is filed noting the status of the application. The completed application will be assigned a queue position. The electric utility shall evaluate the interconnection study within 20 days of completion of the application. If the facility fails level 2 interconnection standards which cannot be remedied with minor modifications, then the facility may request for level 3 interconnection review. 

The electric utility may charge up to $50 plus $1 per kW of the facility’s capacity plus the reasonable cost of any required minor modification to the electric distribution grid or additional review. Costs for such modification or review will not exceed $100 per hour. 

Level 3 interconnection review is used for facilities that fail both level 1 and level 2 processes. The review process includes several detailed studies to evaluate and minimize the impact of the interconnection of the generation facility. 

The electric utility may charge up to $100 plus $2 per kW of the facility’s capacity, as well as charges for actual time spent on any required impact of facilities studies. Costs for engineering work done as a part of the study will not exceed $100 per hour. The applicant must bear the cost of any additional equipment required for interconnection.