Site loading image

Regulatory Updates

NERC Issues Battery Energy Storage Systems Reliability Guidance

Dylan Achey and Tim Farrar, PE | April 22, 2021

Battery Energy Storage Systems (BESS) are rapidly expanding across North American as a solution for improving the reliability of intermittent resources, enhancing power production economics, taking advantage of changes in organized market compensation offerings and building grid resiliency. Additional drivers include changing public policy and technological advancements.

BESS are commonly coupled with inverter-based generating resources. While NERC has recently published a reliability guideline addressing inverter-based resources generally, they are now giving more attention to the various potential uses of BESS and have issued guidance to support effective implementation.

BESS as Hybrid Power Plant Resources

NERC’s BESS guideline defines Hybrid Resources as:

a generating resource that is comprised of multiple generation or energy storage technologies controlled as a single entity and operated as a single resource behind a single Point of Interconnection (POI).

Hybrid resources provide new benefits to the power system by combining operational capabilities involving different technologies. There are multiple hybrid configurations (e.g., AC-coupled versus DC-coupled) and their complexities create a need for additional guidance.

BESS Guidance

NERC’s BESS guideline provides eight recommendations in the areas of Applicability, Performance and Modelling and Studies which should be carefully reviewed by TRC clients as they pursue BESS installation plans. NERC also details the fundamental capability and potential roles of Energy Storage Systems in support of reliability.

The predominant type of hybrid resource currently observed in interconnection queues across North America is the combination of renewable energy (solar or wind) and battery energy storage technologies. Due to this fact, NERC’s guideline concentrates primarily on hybrid plants combining renewable (specifically inverter-based) generation with BESS technology.

Next Steps

Reviewing NERC’s guidance in detail will help you stay ahead of industry and regulatory changes. System studies and interconnection facility design will be critical to moving BESS proposals forward, particularly those utilizing various hybrid configurations.

Our experts can support you with an independent review of your technical assessment of BESS projects from studies through design and construction.

We understand the challenges of implementing energy storage projects from both the developer and utility perspective. Our end-to-end solutions- from project management to engineering design, planning, permitting, construction management and testing and commissioning – ensure success in front of and behind the meter.


About TRC

TRC’s approach to power system planning, design and operations balances solutions that incorporate appropriate standard requirements, regulatory guidance, compliance obligations, best practices, operational goals and budgets. Our work for public and private sector clients is a testament to our understanding of power system operations and planning and our successful application of technological solutions in a constantly evolving business and regulatory landscape.  TRC advises numerous clients how to stay ahead of the curve regarding the technical aspects of their mandatory compliance obligations and business opportunities.

This regulatory update is a service to TRC’s utility clients, helping keep you informed of issues that impact your company’s electric system reliability risks along with related topics regarding regulatory developments to help you achieve your company’s business goals.

Dylan Achey

Dylan Achey is TRC’s Manager of Generation Engineering Services. He has been leading the effort with TRC generation clients on evaluating and providing updates/information so that clients can meet applicable NERC standards. His highly technical staff perform NERC compliance standard evaluations as well as studies for both generation and transmission clients that need assistance on technical issues concerning NERC compliance. Contact Dylan at

Tim Farrar, PE

Tim Farrar is a licensed professional engineer and works as the Protection & Controls Chief Engineer in TRC’s Augusta, Maine office. He is also a Certified Control System Technician (CCST) and Licensed Electrician with an Associate Degree from Eastern Maine Technical in Electrical Power Technology. Tim has 28 years of experience in protection and controls systems engineering for electric utilities and power generation industries including 10 years at Central Maine Power Company and 18 Years in the consulting engineering business. He has held several positions at TRC as an Engineer, Supervisor of Automation and Controls and Electrical Engineering Manager prior to his current position as Chief Engineer.

Contact Tim at

By clicking "Accept", you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Read our Privacy Policy.