Difference between revisions of "HYDROPOWER"

As a control area operator, Western “regulates” the transmission system within a prescribed geographic area. Western is required to react to moment-by-moment changes in electrical demand within this area. Regulation means that “automatic generation control” will be used to adjust the power output of electric generators within a prescribed area in response to changes in the system frequency, time error, and tie-line loading, to maintain the scheduled level of generation in accordance with prescribed NERC criteria. The “record” used to calculate the degree to which Western is responding to these change on the transmission system is called the “ACE” - Area Control Error.

Hydro facilities such as Glen Canyon have an inherent design that allows them to respond rapidly to changes in power system demands. Other control area operators, across the nation, that do not have hydropower plants must either build small units (natural gas or oil-fired being the most likely) or add this capability to the design of larger units.

The transmission system that Western distributes power through is dynamic. Load requirements are constantly changing as a result of either the demands of the customers connected to it or changes that occur in other interconnected power systems. Western maintains the ACE signal to record its response to the fluctuations in system “loading”; (an effort to maintain a balance between power being consumed and power being generated - described above). If more demand is placed on the transmission system than is being generated, the resulting ACE is negative. Generators automatically respond to this condition by increasing generation. If demand is less than generation, ACE is positive. Generators automatically respond to this condition by reducing generation. The targeted ACE is zero.

The ACE signal that is sent to Glen Canyon where it is effectively added to, or subtracted from, the existing scheduled hourly generation base point. Therefore, at any moment during the day or night, Glen Canyon might be producing more or less power than the current hourly megawatt schedule.

The ACE signal is transmitted to Glen Canyon Dam every four seconds. The NERC requirement for regulation is that the ACE must “cross” the zero target every 10 minutes. The frequent “swings” in generation are described in the MOU signed by Reclamation and Western (4):

“These changes which occur many times during the hour are both positive and negative in relation to the schedule. The resulting output from Glen Canyon generators is an envelope of generation swings that are frequent, small in magnitude, the average of which approximates the original schedule.”[2]

In addition to daily scheduled fluctuations for power generation, the instantaneous releases from Glen Canyon Dam may also fluctuate to provide 40 megawatts (mw) of system regulation. These instantaneous release adjustments stabilize the electrical generation and transmission system and translate to a range of about 1,200 cfs above or below the hourly scheduled release rate. Under system normal conditions, fluctuations for regulation are typically short lived and generally balance out over the hour with minimal or no noticeable impacts on downstream river flow conditions.

Releases from Glen Canyon Dam can also fluctuate beyond scheduled releases when called upon to respond to unscheduled power outages or power system emergencies. Depending on the severity of the system emergency, the response from Glen Canyon Dam can be significant, within the full range of the operating capacity of the power plant for as long as is necessary to maintain balance in the transmission system. Glen Canyon Dam typically maintains 30 mw (approximately 880 cfs) of generation capacity in reserve in order to respond to a system emergency even when generation rates are already high. System emergencies occur fairly infrequently and typically require small responses from Glen Canyon Dam. However, these responses can have a noticeable impact on the river downstream of Glen Canyon Dam. [3]

• The Basin Fund
• GTMax Page
• Western Area Power Administration (WAPA)
• Colorado River Energy Distribution Association (CREDA)
• U.S. Bureau of Reclamation (USBR) Power Office
• SocioEconomic Ad Hoc Group (SEAHG) page

• FY16 Annual Report
• FY16 Statistical Appendix
• FY15 Annual Report
• FY15 Statistical Appendix
• FY15 Results of Operations
• FY14 Annual Report
• FY13 Annual Report
• FY12 Annual Report

2023

• Impacts to Hydropower Customers and the Basin Fund from Conducting Experiments
• Glen Canyon Hydropower Production and Value

2022

• Effects of Frequent Use of Bypass at Glen Canyon Dam on Electrical Generation and Transmission
• Update on Project N Activities Including a Discussion of Hydropower Improvement Flows

2021

• Colorado River Storage Project Market Activity and UC Basin Fund Updates
• Glen Canyon Hydropower Production & Value: Status & Trends, 2020

2020

• GCMRC 2019 Annual Reporting Meeting Overview – Part 3
• Colorado River Storage Project Funding Update
• Glen Canyon Dam Overview
• Identifying the total economic value of hydropower at Glen Canyon Dam and implications for adaptive management

2019

• Colorado River Energy Distributors Association (CREDA)
• Glen Canyon Dam Hydropower Production and Value Status & Trends, 2019

2018

• The Future of the Colorado River
• Colorado River Storage Project (CRSP) PPT
• Glen Canyon Dam Hydropower Production and Value, Status and Trends 2018 PPT

2017

• Status and Trends of Hydropower and Energy PPT

2016

• Basin Fund and Revenue Overview

2015

• CRSP Rates, Revenue, and Basin Fund Overview

2013

• Overview of the Colorado River Storage Project (CRSP) Management Center for Western Area Power Administration (WAPA)
• Capacity and Energy Handout
• Question & Answer Transcript
• High Flow Experiments: Financial and Operational Effects on CRSP and the Electric Power System
• Final Products of the 2011 Hydropower Knowledge Assessment and GTMax Model Review Workshop Dated January 4, 2012

2010

• Electrical Power System Economics

2009

• CREDA brief on “the generation of hydroelectric power, as an incident of the foregoing purposes.”
• Life Cycle Impact Assessment of Renewable Electrical Generation Technologies Compared to the WECC Baseline
• Energy and Water Development Appropriations bill, 2010 language (note last paragraph on GCD Adaptive Management Program)
• Letter from various U.S. senators, to Daniel Inouye, Byron Dorgan, etc., Subj: Concerns on Energy and Water Development Appropriations Bill, H.R. 3183

• Generation at Outlet Glen Canyon Dam Plan of Study CRSP Power Peaking Capacity (March 1981)

In GRAND CANYON TRUST vs U.S. BUREAU OF RECLAMATION, Grand Canyon Trust asserted that “[h]ydropower is an incidental benefit of every other stated purpose of the dam,” citing 43 U.S.C. § 620. Pl. Reply at p. 39. This is not a correct statement of the law. The relevant portion of 43 U.S.C. § 620 provides “for the generation of hydroelectric power, as an incident of the foregoing purposes.” Congress did not provide that hydropower is “incidental to” or “an incidental benefit of” the Colorado River Storage Project. Hydropower is an “incident of” the other Congressionally defined purposes. Used in this manner and in this context, the word “incident” means “related to,” or “resulting from,” and does not mean that hydropower resources are an “incidental” or minor authorized purpose of the Colorado River Storage Project. [1]

Alvarez and Schmeeckle (2013) that found that the erosion of sandbars (the primary reason we have ramp rate restrictions at Glen) are not affected by ramp rates themselves. They found that erosion of sandbars is primarily caused by the higher velocity flows that washes the toe of the sandbar away which then causes the rest of the sandbar to slough off and fall into the river (i.e. mass failure). Having flows come up or go down more quickly than they do now will not increase this rate of erosion aside from the fact that the faster you can come up and go down allows you more time on peak at those higher velocity flows, which was identified as the causal factor of sandbar erosion.

• Under Pressure: Dams make less electricity in drought
• Wave attenuation of hydropower releases at Glen Canyon Dam
• CREDA Fact Sheet on Hydropower and Glen Canyon Dam
• Capacity & Energy handout
• Explanation on Why Capacity is Important
• Importance of Hydropower Capacity
• Video: What is Black Start?
• Video: How does a Transformer work?