The Maryland Public Service Commission, after nearly two years of deliberation, has adopted updated rules 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, two-phase effort within the PC 44 Proceeding, Transforming Maryland’s Electric Grid.

The first phase of the effort culminated in establishing initial guidance and clarification regarding the process through which energy storage projects should connect to the grid; the second phase dealt with some of the more contested issues that could not be resolved in phase I.

As part of the phase II effort, Commission staff led a collaborative workgroup consisting of utilities, the Energy Storage Association (ESA), the Interstate Renewable Energy Council (IREC), SunRun, the Center for Renewables Integration, and other Maryland stakeholders – after several months, the stakeholders presented a largely consensus set of recommendations to the Commission. The adopted changes to the state’s interconnection standards will support a more streamlined, efficient, and cost-effective process to connect energy storage and solar-plus-storage projects to the grid.

“Interconnection standards are a linchpin to the advent of a more modern grid,” explained Sara Baldwin, 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.”

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. 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.

“Even in the midst of the COVID pandemic, Maryland regulators took an important step to remove barriers for customers looking to enhance their resilience by installing energy storage in their homes and business,” said Kelly Speakes-Backman, CEO of ESA. “The Public Service Commission wisely adopted common-sense reforms to the interconnection process, such as examining customers’ intended use of solar-paired energy storage systems and making accommodations that provide better reliability for customers with storage.”

The following are the most notable changes to the rules:

The rules require interconnection requests for energy storage to be evaluated based on “net system capacity” and as defined by the “proposed use.” These relatively new concepts are a key change that will allow energy storage systems (as well as solar-plus-storage systems) to be reviewed and studied according to the actual design and intended use of the project. It will also allow that process to take into account the applicable controls that will be used to keep the system within the parameters of its intended operational profile.

The rules allow certain energy storage systems to export power onto the grid for time-limited durations under certain conditions. This change is an important step in determining the appropriate interconnection review for those projects that are largely designed to serve on-site customer load but that might “inadvertently export” as a result of a sudden customer load fluctuations.

Utilities will be required to publicly and electronically provide an interconnection queue (updated monthly), providing key information to help inform prospective interconnection applicants about the volume, types, and locations of other projects in the queue. Over time, this published queue and reporting will also help inform whether there are opportunities for process improvements and/or modifications to how the queue is managed, as the volume of projects seeking to the connect grows over time.

Effective January 1, 2022, the rules require utilities to establish default utility-required smart inverter setting profiles. Commission staff will lead a phase III workgroup effort to help inform the integration of the IEEE Standard 1547™-2018 for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interface and the requisite inverter setting profiles.

The rules require Maryland utilities to establish hosting capacity policies and reports – such as designating closed and restricted circuits and reserve hosting capacity. Further clarification around this will also be taken up as part of phase III.

The rule clarifies that utilities in Maryland may not charge a processing fee for Level 1 interconnection projects, which are typically smaller residential projects.

“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.”

“We applaud Maryland’s proactive steps to update their interconnection rules, which will ensure the state, the grid and the utilities are better equipped to handle current and anticipated growth customer-driven energy resources, while also supporting more clean energy on the grid,” said Nicole Sitaraman, Senior Manager of Public Policy for SunRun.