EPRI releases report on best practices at Alaska plants
EPRI announces availability of a report on the results of Ketchikan Public Utilities’ assessment of performance best practices and implementation of performance improvement projects at its four hydro plants in Alaska. The report says that through this work, the utility increased generation and profitability at these plants: 5-MW Beaver Falls, 4.2-MW Ketchikan, 2.1-MW Silvis, and 22.6-MW Swan Lake.
This Hydropower Technology Roundup Report, the twelfth published by EPRI, discusses Ketchikan Public Utilities’ experience with improving the overall performance of its hydroelectric plants, says Patrick A. March, principal consultant with Hydro Performance Processes Inc. and author of the report. The report uses a best practice approach based on the Protocol for Appraisal of Hydro Performance Processes, March says. This protocol addresses four aspects of operational performance, including unit performance data, organizational use of performance results, optimization, and integration with business processes and systems.
In 2004, the utility used an informal initial appraisal to identify gaps in its performance best practices at these four plants. Ketchikan Public Utilities then initiated numerous performance improvement projects. In November 2008, a follow-up appraisal documented improvements that resulted from these performance improvement projects.
Projects implemented include: improving flow measurements, determining detailed unit performance characteristics, improving operations using these performance characteristics, analyzing and reviewing performance data to achieve further improvements, and implementing operational rules based on the performance analyses.
The report provides results from the initial and follow-up performance appraisals, performance characteristics for each plant, and results from the detailed performance data analyses.
– To purchase a copy of this report, contact EPRI Customer Assistance Center at (1) 800-313-3774; E-mail: firstname.lastname@example.org.
Studying effects of pulsed flows in California
The Center for Aquatic Biology and Aquaculture of the University of California, Davis, is operating a pulsed flow research program to determine the effects of pulsed flows from hydro projects on aquatic habitat and biotic communities in California streams and rivers.
A pulsed flow involves a sharp, sudden increase in the amount of flows for a relatively short period of time, and then a decrease back to the original flow level. According to the center, more than 380 hydro projects in California release pulsed flows as a byproduct of electricity production, for recreational purposes, or for sediment management.
Because the effects of these pulsed releases are poorly understood, in 2002 the Public Interest Energy Research (PIER) program of the California Energy Commission and the Division of Water Rights of the State Water Resources Control Board established and provides funds for the pulsed flow program. Since 2003, nine research projects have been awarded funding, and seven are now complete.
Two ongoing projects are studies of:
– Gaps in scientific understanding of instream flows and research needs related to developing economically efficient and ecologically effective management tools for use in the Federal Energy Regulatory Commission hydropower relicensing process; and
– Effects of aseasonal pulsed flows on the Foothill yellow-legged frog. This frog has disappeared from as much as 45 percent of its range in California, possibly due to water released from reservoirs washing away eggs and forcing adult frogs to leave streams.
Findings from some of the seven completed projects include:
– Preventing sharp fluctuations in water levels from April through June (breeding season for the Foothill yellow-legged frog on the North Fork Feather River) can enhance breeding success of this species;
– Under slow flow conditions, increasing water velocities associated with pulsed flows may decrease the severity of infection with the parasite Ceratomyxa shasta in fish (such as salmon) in the Klamath River;
– Seasonal pulsed flows for channel maintenance/recreation in the Pit River should be scheduled during or after September to minimize interference with reproduction of freshwater mussels;
– Pulsed flows from hydro projects have no significant effect on the distances certain fish species (rainbow trout, brown trout, hardhead, and Sacramento suckers) move before, during, or after the release of the flow or on the number of fish in a particular river reach; and
– Operators of hydro projects in the snow/rainfall transition zone of large Sierra Nevada river watersheds should develop a specific regimen to release pulsed flows that will help recover and sustain the river ecosystems (which are significantly affected by the annual snow melt and winter floods).
– For more information, visit the website: http://animalscience.ucdavis.edu/pulsedflow/index.htm.