The Maryland Public Service Commission adopted updated rules this week for connecting distributed energy resources (such as solar and energy storage systems) to the electric grid. The updated rules will improve the efficiency of the interconnection process for customers and utilities, increase grid transparency, and enable a clearer pathway for energy storage and solar-plus-storage systems.

A virtual rulemaking session held on March 31, 2020 codified several proposed changes to the Code of Maryland Regulations (COMAR) and marked the culmination of a four-year effort within the PC 44 Proceeding, Transforming Maryland’s Electric Grid.

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“Interconnection standards are a linchpin to the advent of a more modern grid,” explained Sara Baldwin, Interstate Renewable Energy Council (IREC) Vice President – Regulatory. “The adoption of next-generation best practices, especially to address the uniquely flexible and controllable nature of energy storage, will create a clearer path for this game-changing resource to play a bigger role going forward.”

Storage helped big time

Energy storage is becoming increasingly popular as costs decline and more customers and communities seek to improve resilience and control energy costs. From a technical standpoint, energy storage differs from distributed generation, like rooftop solar, in that it is controllable. Many energy storage systems can be designed with the capability to limit or prevent export onto the grid, which impacts how the system should be studied and interconnected to the grid.

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Maryland’s rules now more appropriately reflect this unique characteristic of energy storage and provide a clearer approach for review that minimizes the time and cost to interconnect.

Notable changes include the requirement that energy storage systems be evaluated based on “net system capacity” and as defined by the “proposed use,” important distinctions that will ensure a project’s evaluation is based on its actual design and intended use.

Utilities in Maryland will now also be required to provide greater transparency into the interconnection queue, providing key information to help inform prospective interconnection applicants about the volume, types, and locations of other projects in the queue. Information on other notable changes in the updated rules can be found here.

Next up: smart inverters

In addition, effective January 1, 2022, the rules require utilities to establish default utility required smart inverter setting profiles. This requirement sets Maryland on a path to integrate into their interconnection standard the expanded capabilities for distributed energy resources enabled by the IEEE Standard 1547-2018 for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interface.

“Excellent to see Maryland chart a clear path forward for smart inverter adoption,” said Harry Warren, co-founder of the Center for Renewables Integration, who chaired the Smart Inverter workgroup. “States that have not yet defined their own paths should follow Maryland’s lead to be ready for widespread availability of new inverter technology in the months ahead.”

The adopted changes to the state’s interconnection standards are reflective of recommendations from a collaborative Commission-led workgroup that included utilities, the Energy Storage Association (ESA), the Interstate Renewable Energy Council (IREC), Sunrun, the Center for Renewables Integration, and other Maryland stakeholders. The changes will support a more streamlined, efficient, and cost-effective process to connect energy storage and solar-plus-storage projects to the grid.