Resource Adequacy

Innovation Gaps

A Simple Roadmap to Address Emerging Resource Adequacy Challenges

Supply-Side Resource Modelling

Continued evolution of how resources are quantitatively modelled in the adequacy assessment process is essential to proper planning and operations as resource mixes change rapidly around the world. Basic assumptions and approaches to modelling both new technologies (e.g., renewables, storage and distributed resources) and conventional resources whose operational profile is changing substantially (e.g., combined-cycle gas turbines (CCGTs), nuclear) may need to be adapted to the operations expected over the horizon of the RA study. 

Building new models or adjusting existing models for these resources and their availability is necessary and needs to include a forward-looking approach that captures how such resources may behave in the future, with the use of historical performance data where available. The goals of this research are to understand the physical capabilities of existing and emerging resources and to model likely availability given competing and changing use cases.

Customer Demand

Consumer demand for electricity is evolving into increasingly sophisticated, customizable technology with new behaviours emerging in response to new incentives. Increased electrification of heat and transport, particularly, load control through smart thermostats and water heating, building controls, flexible industrial loads (e.g., water pumping), onsite generation, storage, and the impacts of tariffs or retail incentives all interact. Their interaction makes identifying firm demand, where shedding that load would be involuntary, and demand that voluntarily contributes to balancing the system, an important factor in adequacy studies. This will require more-detailed future customer demand profiles. It is likely that flexible demand’s role is increasingly important for mitigating events such as those observed in the 2020 summer rolling outages in California, as methods improve, and the market evolves.

Operators need additional demand components to be forecasted accurately, and their contribution to meeting resource adequacy better quantified, thus ensuring they can mitigate scarcity. Therefore, a mind shift is required in how the industry thinks about demand contributions to resource adequacy, moving from RA answering the question “are there enough generators to meet expected demand, with some target level of certainty?” to “can supply and demand find balance without shedding load involuntarily, with some target level of certainty?” This new formulation raises demand’s role as equal to supply in finding balance. 

EPRI is performing ongoing work in this area, examining adequacy contributions of various demand side resources, and assessing the need for studies to consider such demand. The goals of this research are to envision future customer demand and net demand from the grid, with electrification, customer-owned generation, and new tariff structure, and the ability of emerging resources to support resource adequacy needs. 

Developing Planning Scenarios

As both supply and demand become more variable and uncertain, future scenarios may occur across a broader range of conditions. Planners need abilities to study the set of scenarios that represent the distribution of uncertainties affecting the economics or efficacy of investments and/or the methods of operation. This may include paying closer attention to imports and demand in neighbouring regions. Scenarios also need to be built reflecting future conditions envisioned with climate change in mind, not merely sampling from historical years. A robust scenario set reflects future outcomes sufficiently for describing meaningful insights to decision makers when procuring or approving.

Standards, Guidelines, and Criteria

The front line of defence for safe and reliable electric power is agreement on standards and guidelines, shepherded by technical expertise. EPRI and its member utilities collaborate on evaluating reliability metrics that consider extreme events, new and emerging resources and increased consideration of demand side resources. These need to be developed and applied in a manner that accurately reflects the risk, and criteria set to ensure that adequacy is maintained at levels that can be justified. The goal is to understand which measures best reflect adequacy and other related risks, and what appropriate levels of resource adequacy entail.

Simulation Tools

As power systems evolve, the challenge and importance of understanding them is imperative. Simulation tools may address more of these complexities to ensure that the goal of RA assessment is met. This includes chronological modelling (e.g., moving to hourly or even 5-minute models), improved representation of demand-side resources and other emerging technologies, appropriate representation of operational decisions such as storage charging or imports, and the ability to produce more insightful metrics and analysis. Such tools should identify how different mitigating options can address shortfalls, while recognizing how operations and markets may evolve. 

EPRI is working to enable simulation tools to provide insightful information that can assist assists decision makers to explore alternative futures. The goal of this research is to create tools to model systems with the requisite level of detail to measure supply shortfall risk with sufficient accuracy, and to provide actionable information based on detailed simulation models that is explainable to decision makers.

A Simple Roadmap to Address Emerging Resource Adequacy Challenges

EPRI actively researches RA topics and has developed a detailed understanding of the issues. To address these, resource planners, regulators, and power-sector stakeholders can follow the following simplified roadmap to unlock capacity from the grid’s resources that will be needed now and into the future. The roadmap is divided into three phases of action: Right Now, Next, and Then, each with a suggested action for resource planning groups. The effectiveness of each action depends on the unique current and future situations of each grid.

Right Now

  • Tools & Methods: Adopt methods and study tools that capture risk across the full study period, not just at peak (i.e., 8760 hourly models).

  • Scenarios: Choose demand and weather profiles that cover multiple years and are representative of the best estimate of future expected conditions. They may be different from historically observed conditions.

  • Resources: Gather data and begin to use new methods to assess RA contributions from emerging technologies including renewables, storage, hybrid power plants, leveraging the latest resource models.


  • Tools: Include flexibility considerations in planning and expansion models to inform investment.

  • Distributed Resources: Account for distributed resource RA contributions, considering local limits on their ability to support the system, as well as the unique characteristics of these devices. These may include rooftop PV, customer-located batteries, electric vehicles, etc.

  • Customer Demand: Develop models of 'non-firm' grid interconnection options for assets that limit export during pre-defined conditions.


  • Standards: Adopt a risk-based probabilistic approach to grid and resource expansion.

  • Valuation: Plan for an increased exchange of grid services between distribution and transmission.

  • Energy Systems Integration: Assess the interaction of other energy systems, including heat, transportation, etc., in electric system resource adequacy, both in terms of the demand due to increased electrification and the ability of these systems to provide flexibility and capacity.

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