Several different scenarios are provided to help you evaluate capacity across a range of use cases and grid conditions to provide a holistic picture of forecasted capacity.
Scenarios
Grid operators analyze new connection requests across various potential scenarios to identify the most severe case for project evaluation. This worst-case scenario assessment is crucial for maintaining grid reliability, enabling proactive mitigation of any constraints identified during planning before they occur.
To mirror this process, we provide a diverse set of scenarios relevant to specific regional conditions. The scenarios are named based on what each grid operator provides.
Developers should adopt a conservative approach by analyzing the most limiting scenario relevant to their specific flow direction.
Key characteristics
To understand these scenarios, pay attention to the key characteristics described below.
Flow direction
Injection: This analysis shows the maximum amount of power you can send into the grid at a given Point of Interconnection (POI). It’s useful for evaluating how much capacity is available for new generation projects like solar, wind, or batteries that will inject power into the system.
Withdrawal: This analysis shows the maximum amount of power you can pull from the grid at a specific Point of Interconnection (POI). It’s useful for understanding whether the grid can support new energy demands, like powering a data center or charging an energy storage system.
Weather scenario/load level
☀️Summer Peak: This scenario models the grid during the hottest days of summer, when electricity demand is at its highest (think widespread use of air conditioning). It helps make sure the grid can stay reliable when it’s under the most stress, and that new projects won’t run into issues during these peak times.
❄️ Winter Peak: This scenario reflects the highest electricity demand during the coldest days of winter, when heating systems are running full blast. It ensures the grid — and any new project — can meet those seasonal energy needs without causing issues.
🌱 Spring Light Load/Light Load: This scenario represents periods when electricity demand is low, like during spring or late at night. It’s useful for checking how new projects will perform when the grid isn’t heavily loaded, and can help flag any issues that might show up under minimal demand conditions.
Deliverability – Service request type (ERIS vs. NRIS)
Based on your project goals the following service types are applicable to generation projects and defines the reliability that energy will be able to be moved:
ERIS – Energy Resource Interconnection Service
ERIS allows a generator to connect to the grid and deliver power when the system can handle it. It’s a more flexible, lower-cost option that typically avoids major upgrades, but it doesn’t guarantee access during times of grid congestion.
Use case: Suitable for generators whose primary goal is to sell energy when space is available on the grid and who may not need to guarantee delivery to specific loads or participate in capacity markets that require firm transmission.
NRIS – Network Resource Interconnection Service
NRIS gives a generator firm guaranteed access to the grid, similar to existing network resources. It ensures your project’s power can be fully delivered even during peak conditions, but usually comes with higher costs and more system upgrades to support that reliability.
Use case: Essential for generators that need to ensure their power can be delivered reliably, want to qualify as a capacity resource (e.g., to participate in capacity auctions), or have contractual obligations to deliver power to specific customers.
Queue inclusion
This analysis takes into account how other projects in the interconnection queue might impact available capacity. As explained in each region’s methodology guide, the scenarios can vary — some include only late-stage (more likely) projects, while others take a more conservative view by including early-stage (less certain) projects too. Depending on the region, the analysis might also focus on specific queue clusters or include all queued projects to reflect different planning conditions.
Example use case
A developer who wants to understand constraints for a potential site in Texas should examine the Summer Peak scenario, as the Texas grid is most constrained during the heat of summer. For a more conservative approach, analyze the Summer Peak Stressed scenario, as the stressed scenario includes more early stage projects that may interconnect before the project currently being evaluated.
While this provides a general guideline, it’s important to review all scenarios to determine the minimum injection/withdrawal amount. In many regions of the country, there isn’t a definitive season that stresses the grid the most, so that’s why it’s important to look at all scenarios.
Transmission planning aims to identify and alleviate constraints under the worst-case scenario; therefore, when conducting due diligence, developers should adopt a conservative approach by analyzing the most limiting scenario relevant to their specific flow direction.