Energy storage deployment is growing and interconnection rules have, for the most part, not yet been updated to reflect best practices on how they should be reviewed in the interconnection process. With funding from the Department of Energy, solar industry groups such as IREC, SEIA, CALSSA, EPRI and others have worked for over a year to identify the biggest barriers to storage interconnection and develop solutions to them. This work has resulted in a new toolkit has practical solutions for utilities and utility regulators to update their interconnection policies.
The Toolkit and Guidance for the Interconnection of Energy Storage and Solar-Plus-Storage provides vetted, consensus-based solutions to eight regulatory and technical barriers to the interconnection of energy storage and solar-plus-storage systems to the distribution grid. Adoption of these recommended solutions can have a significant impact on how many distributed energy resources (DERs), like residential and commercial solar PV systems, can be added to the grid.
The Toolkit also includes model language that utility regulators can use to update state interconnection rules to reduce the costs and time to safely interconnect energy storage and solar-plus-storage systems. The solutions are nationally applicable and can be applied in diverse states and markets across the U.S.
“By modernizing the rules that govern the interconnection of energy storage systems, regulators and utilities can enable significantly more renewable energy on the distribution grid—in some cases as much as double the capacity,” said Larry Sherwood, IREC President and CEO. “They can also make the interconnection process faster, predictable, and less costly for applicants. These changes are urgently needed as more and more states target bold climate and clean energy goals; fortunately, the Toolkit provides regulators with actionable and ready-to-implement guidance.”
For example, original research for the Toolkit found that when energy storage is used to control the export of energy from DERs, the grid can host more DER capacity. In the most pronounced cases, modeling and simulation research found that using storage to limit DER export can double available DER capacity on a circuit.
The Toolkit is the result of a multi-year project called “BATRIES” (Building a Technically Reliable Interconnection Evolution for Storage), supported by a cooperative agreement with the U.S. Department of Energy Solar Energy Technologies Office.
The project team is led by the Interstate Renewable Energy Council (IREC) and includes the Electric Power Research Institute (EPRI), the Solar Energy Industries Association (SEIA), the California Solar & Storage Association (CALSSA), utilities New Hampshire Electric Cooperative Inc. (NHEC) and PacifiCorp, and law firm Shute, Mihaly & Weinberger, LLP (SMW).
Another important finding: ESS is unique from other DERs like solar and wind, because it can control how much energy is sent to the grid at different times. Interconnection rules historically have not recognized how storage operates differently from other electricity generators, leading to review processes that may be more likely to reject an interconnection request or require grid upgrades that may not be necessary.
The Toolkit solutions address critical storage interconnection issues, including (but not limited to) how to safely and reliably address inadvertent export and solutions for interconnecting limited- and non-exporting systems.
“If we’re able to more efficiently connect energy storage to the grid, costs will plummet, making solar-plus-storage systems more affordable and accessible to families and businesses,” said Jeremiah Miller, Director of Storage Markets and Policy at the Solar Energy Industries Association (SEIA). “This project will help us speed interconnection times and make it easier to connect solar-plus-storage systems of all sizes to the grid. By 2023, nearly one in four distributed generation solar systems could be paired with energy storage.”
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