Electricity reliability has long been measured by a simple question: is there enough generation capacity available to meet peak demand? But as the power system changes, reliability challenges are becoming more complex, requiring new ways of thinking about how electricity supply and demand interact throughout the year.

That question was front and center at a recent North American Electric Reliability Corporation (NERC) workshop that I participated in, where regulators, grid operators and policy experts gathered in Atlanta to discuss how reliability planning must evolve as the electricity system changes. As electricity demand grows, generation resources diversify, and extreme weather events stress the grid, ensuring reliability will require more than traditional peak-capacity planning. It will require closer collaboration among NERC, states and regional grid operators to develop reliability standards that can be tailored to the particular situation in a state or region; there is no one-size-fits-all standard that can reflect the wide range of conditions across North America.

Reliability risks are changing

For decades, reliability planning focused on ensuring that the power system had enough capacity to meet peak demand typically the highest-load hours of the year. This framework has served the grid well, but modern reliability challenges increasingly occur outside traditional peak conditions.

Extreme weather events have highlighted these risks. During Winter Storm Uri in February 2021, extreme cold, gas plant outages and surging electricity demand overwhelmed available resources across much of Texas.

In other cases, reliability risks have emerged when weather patterns reduce renewable generation across large geographic areas. For example, “dunkelflaute” events (when wind and solar output are both unusually low for days or weeks) can strain systems with growing shares of renewable generation.

These events highlight a key challenge: reliability risks are no longer confined to peak demand hours. Planning must increasingly assess whether sufficient energy and flexible resources are available across all hours and conditions.

NERC’s energy assurance initiative

Recognizing these evolving challenges, NERC issued a Standards Authorization Request (SAR) in 2022, that initiated the creation of the Energy Reliability Assurance Task Force, charged with developing a new energy assurance reliability standard. The goal is to ensure that utilities assess whether they have sufficient energy and operational flexibility to maintain reliability throughout the year, not just during peak demand hours.

The formal comment period on a draft standard commenced in October 2025, with regulators, utilities and other stakeholders submitting comments on the proposal. The issues identified in this initial comment period were the focus of discussion at NERC’s February workshop in Atlanta, which included panels featuring perspectives from state regulators, regional organizations and industry participants.

The conversation highlighted that the changing nature of electricity supply and demand means that reliability planning must evolve. But it also highlighted a critical challenge: how to develop reliability standards that reflect the wide range of conditions across the North American power system.

Regional solutions are already emerging

Across the country, states and regional grid operators are already developing new approaches to address evolving reliability risks.

In the Midcontinent Independent System Operator (MISO) region, state regulators working through the Organization of MISO States (OMS) have been actively engaged in evolving energy adequacy and reliability planning to address the reliability challenges presenting in different times of the year. For example, MISO has established seasonal resource requirements like the Planning Reserve Margin Requirement (PRMR) and the Local Clearing Requirement (LCR). The MISO tariff also specifies accreditation methods for a variety of energy resources. State regulators and grid planners have also evolved their resource planning tools to reflect emerging resource and demand fundamentals.

In the West, grid operators and regulators have also developed new mechanisms to address emerging reliability challenges. The California Public Utilities Commission, for example, has introduced new planning approaches to ensure sufficient flexible resources are available to manage changing supply and demand in each month of the year by introducing a “slice of day” approach.

The innovations at MISO and the CPUC are not isolated examples as other states, utilities and regions have proactively improved their data and analysis beyond what NERC’s legacy system peak standard required.

The comments filed on the draft NERC standard indicate that many of these improvements are tailored to the systems and operating conditions of the utility or region. These state and regional efforts demonstrate that electricity systems across North America operate under different conditions and will require regionally specific reliability standards. Resource mixes vary, electricity markets are structured differently, and weather patterns create unique operational challenges in different regions. As a result, the tools and policies used to ensure reliability must be tailored to regional needs.

Collaboration is essential

NERC’s effort to address energy assurance is both timely and important. A national reliability standard can help ensure that utilities are evaluating emerging reliability risks and taking steps to address them. At the same time, reliability planning in North America is inherently regional. States play a central role in energy resource planning, and regional grid operators manage system operations in diverse geographies. For a national reliability standard to be effective, it must be flexible enough to allow states and regions to account for these differences and tailor their approach to their situation. NERC needs to ensure that any new standard accommodates and builds on the work already underway in regions across the country.

That makes collaboration essential. The process of developing NERC reliability standards will benefit from the insights of state regulators and regional organizations that are already grappling with these issues in real-world planning and operations. At the same time, state regulators and regional entities must actively engage in that process to ensure their perspectives and experiences inform the development of national standards.

Developing effective energy assurance standards will require both flexibility and collaboration, allowing national reliability goals to be met while recognizing that the paths to achieving those goals may differ across regions.

Looking ahead

As the electricity system evolves, reliability planning needs to evolve with it. The development of energy assurance standards represents an important step in that process.

Ensuring those standards strengthen reliability across North America will depend on meaningful collaboration among NERC, states, and regional grid operators. Aligning national standards with the approaches already working across regions can help reliability planning adapt to a changing power system while preserving the flexibility needed to address regional challenges.