This article comes from law firm Stoel Rives LLP (www.stoel.com)
The Federal Energy Regulatory Commission (FERC) has taken another step to amending transmission practices that unduly discriminate against variable energy resources (VERs) such as wind and solar generators. In November, 2010, FERC first proposed changes to the pro forma Open Access Transmission Tariff (OATT) and large generator interconnection agreement that intends to reduce the costs of integrating large amounts of VERs on the transmission system. FERC proposes to require:
- transmission providers offer transmission service that can be scheduled on 15-minute intervals,
- interconnection customers that operate VERs to provide forecasting and meteorological data to transmission providers deploying or developing or both power production forecasting processes, and
- add Schedule 10 – new for generation regulation (i.e., integration) services. The proposed rule is the first to come out of the Notice of Inquiry on VERs that FERC issued in January 2010.
FERC proposes that transmission providers give customers the option to schedule transmission service at 15-min. intervals. In doing so, FERC proposes that 15-min. periods become the new default scheduling interval, which will allow for scheduling consistency across multiple transmission systems. Transmission has been scheduled on an hourly basis with schedules generated 20 to 30 min. before the hour. Hence, schedules can be 90 min. old by the end of an operating hour, causing transmission providers to rely heavily on reserves to make up for imbalances in the energy output from VERs. The Commission recognizes the process as unduly discriminatory and results in inefficient use of transmission and generation resources to the detriment of consumers.
Under the proposed rule, however, all transmission customers will be given the option to schedule transmission service on shorter intervals, thereby allowing transmission providers to rely more on accurate schedules (and less on reserves) to keep the transmission system in balance and offer greater efficiency in dispatching all resources. FERC proposes that the costs of implementing intra-hour scheduling will be recovered through Schedule 1 (Scheduling, System Control and Dispatch Service) to the OATT.
FERC further proposes that transmission providers who charge for generation regulation service under the newly proposed Schedule 10 must use power-production forecasting to enhance their transmission system’s flexibility and, ultimately, reduce the reserves that transmission providers must hold to maintain system balance. FERC believes that power production forecasting can improve the efficiency of reliability unit commitments (using day-ahead and intra-day forecasting timeframes) and dispatch instructions (using hour-ahead or shorter forecasting timeframes), and provide for the greater predictability of VER ramping events. To get power-production forecasting up and running, FERC proposes reforming the pro forma interconnection agreement to require VERs to supply meteorological and operational data to their transmission providers on intervals at or near realtime. What’s more, the Commission proposes transmission providers and interconnection customers will negotiate resource-specific forecasting requirements into interconnection agreements, taking into account the size and configuration of individual VER facilities, in addition to their characteristics, location, and impact on resource adequacy and reliability. Also, to improve accuracy in power production forecasts, FERC proposes to require VER interconnection customers to report to their transmission providers any forced outages that reduce the generating capability of a resource by 1 MW or more for 15 min. or more.
FERC seeks comment on the type of forecasting and meteorological data to be required of VER interconnection customers. The Commission also seeks comment on its proposed definition of VERs as “an energy resource that is renewable, cannot be stored by the facility owner or operator; and has variability beyond control of a facility owner or operator.” The proposed changes would be limited to VERs larger than 20 MW, although FERC seeks comment on whether to apply the new rules to VERs 20 MW and smaller.
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