On Wednesday, the NERC Integration of Variable Generation Task Force (“IVGTF”) released a special report (“IVGTF Report”) detailing significant changes for system planning and operations to reliably integrate high levels of variable resources into the North American bulk power system. The IVGTF Report, “Accommodating High Levels of Variable Generation,” explains the challenges associated with integrating large amounts of variable generation and identifies current problems and future solutions to ensure reliability within the system.
The IVGTF Report first details how quickly variable generation is growing. For instance, there are 25 states that currently require renewable resources to contribute up to 30% of a utility’s energy portfolio within five to fifteen years. In 2003, only ten states had similar requirements in place. Additionally, NERC predicts that the North American bulk power system will take on 145,000 MW of new variable resources in the next decade. This power is approximately seven times more than the variable generation levels experienced in 2008.
With these dramatic increases in variable resources, NERC believes that the bulk power system will face new and unique challenges. First, variable resources cannot be currently controlled or stored. Second, variable resources, such as wind, are often located in areas where demand is relatively low. Third, variable resources often produce steep ramp outputs, which can lead to operational problems, especially when demand is increasing.
To address these areas of concern, the IVGTF Report recommends several changes for the electrical industry. These recommendations are summarized below.
Transmission Planning and Resource Adequacy
- All parties, including those within state and federal government, should work together to study the impacts of variable generation integration and help site, approve, and construct transmission lines in an efficient manner in order to accommodate new transmission demands from wind, solar, and ocean power.
- System planners must adopt comprehensive planning approaches that will account for distributed variable generation and their related impacts on the distribution system, particularly from local wind plants and rooftop solar panels.
- The electrical industry should expand research and development programs on probabilistic power system planning techniques in order to accurately quantify the risk associated with certain planning options.
- As new resources and their associated equipment become more distributed, new minimum requirements and market mechanisms will be needed to guarantee that the bulk power system maintains its reliability and desired characteristics.
- The electrical industry should improve forecasting methods while continuing to develop demand response and storage technologies to expand new, flexible resources.
Power System Operations
- Both the government and the electrical industry should improve forecasting methods in general while focusing on specific features such as weather alerts and ramping.
- All parties should keep relevant agencies, policymakers, and regulators informed on the benefits of using larger balancing areas and more frequent scheduling intervals in order to reduce variability and ensure reliability.
The IVGTF Report also recommended, among other things, that NERC should prepare a reference manual that will help both planners and operators as the bulk power system integrates large amounts of variable generation. At the same time, the IVGTF Report encourages the electrical industry to design similar interconnection standards so that all related requirements are applied consistently.
NERC originally created the IVGTF in December 2007 as NERC recognized that integrating large amounts of variable generation into the North American bulk power system was necessary. The IVGTF Report can be found in its entirety on NERC’s website at: http://www.nerc.com/files/IVGTF_Report_041609.pdf.