On January 20, 2011, the Federal Energy Regulatory Commission (FERC) posted, and solicited comments upon, a report prepared by the Lawrence Berkeley National Laboratory, "Use of Frequency Response Metrics to Assess the Planning and Operating Requirements for Reliable Integration of Variable Renewable Generation” and its five supporting papers (collectively, “the Report"). Among other things, the Report is expected to be used to help FERC develop policies relating to the issues raised in the Report, including the use of advanced energy storage technologies and electric vehicles going forward. The Report is attached to this email, and is available on the FERC website at http://www.ferc.gov.
As FERC described in its Notice Inviting Comments on Report ("Notice"), “frequency response measures how the bulk power system performs in responding to a sudden loss of generation that could cause reliability problems such as blackouts.” The purpose of the Report is to examine the use of frequency response as an objective measure for evaluating the reliability impact of increased amounts of renewable resources. Among other things, the comments received by FERC may very well prove influential in shaping policies that impact the market for advanced technologies that can be utilized to perform frequency regulation. Comments on the Report are due March 7, 2011, 45 days from the date of the January 20 Notice.
As the Report notes, "an interconnected electric power system is a complex system that must be operated within a safe frequency range in order to reliably maintain the instantaneous balance between generation and load." This is accomplished by ensuring that adequate resources must always be available to respond to expected and unexpected imbalances and to restore frequency in order to ensure uninterrupted electric service to customers. Ensuring that the lights stay on during such events requires the continuous availability of a critical component of operating reserves called primary frequency control reserves. These reserves are normally provided by conventional generating units; however if the actions of these primary frequency control reserves are not sufficient, frequency will continue to decline, and the ultimate outcome could be the interruption of electric service to large blocs of customers (or a blackout).
The Report observes that the increased use of variable renewable generation (such as wind) will have several impacts on the adequacy of primary frequency control reserves, not the least of which involves increased demands on secondary frequency control reserves. These reserves are slower forms of frequency control that will experience an increase in their use as a result of the integration of more variable renewable generation. If these demands exceed the capabilities of secondary frequency control reserves, primary frequency control reserves (that are set-aside to respond to the sudden loss of conventional generation) will be used to make up for the shortfall. The remaining primary frequency control reserves may be insufficient to maintain reliability and service in the event of a sudden loss of a large conventional generator. Given the critical role that primary and secondary frequency control reserves serve in maintaining the reliability of the grid, transmission system planners must schedule, commit, and maintain adequate primary and secondary frequency control reserves during normal operation in order to assure reliable operations after sudden losses of generation.
Renewable Energy Generation
The increased integration of variable renewable generation is bringing more attention to this issue, as such sources may displace generation that otherwise would provide primary and secondary frequency control reserves. The Report identifies displacement of these sources as a potential reliability impact of increased variable renewable generation, but also notes there are many currently under-utilized and potential future sources of primary and secondary frequency control available (other than conventional generation). Tapping these sources will facilitate the reliable integration of increased amounts of variable renewable generation.
Among these sources, and one that the Report identifies as requiring more study, is the expanded use of advanced technologies, such as energy storage and electric vehicles. To that end, the Report notes:
there are several promising research and development demonstrations of energy storage technologies providing frequency control services (e.g., regulation). More time will be required to fully develop all of these sources, particularly those that are not yet commercially proven. However, there may be significant opportunities that exist and they should be pursued immediately. Efforts to expand the supply of primary and secondary frequency control reserves through advanced technologies should be accelerated.
FERC welcomes comments on this or any other aspect of the Report. Given FERC's interest in hearing viewpoints from all segments of the electric industry, including technology developers and providers, in the formulation of its policies, interested parties should consider submitting comments.