# Presentation: 510293

## Western Area Power AdministrationRocky Mountain RegionGeneration and Marketing

- Ancillary Services Technical Workshop
- March 18, 2004
- --Ron Steinbach

## Western Area Power Administration

- Five Regions
- 10,000 MW installed capacity
- 15 separate Congressionally authorized multipurpose projects
- Water requirements are project specific and dictate project operations
- Power operations are secondary (or lower)

## Rocky Mountain Region Generating Capability

- Four River Systems
- 20 Powerplants; 39 units
- Installed Capacity: 830 MW
- Operating Capability (FY 02): 744 MW
- Average Annual Generation: 2,160 GWH

## Four Major River Basins

- Pick-Sloan Missouri Basin Proram
- Bighorn River Basin
- North Platte River
- Colorado-Big Thompson (CBT)
- Fryingpan-Arkansas (Fry-Ark)
- Fry-Ark’s main feature—Mount Elbert—is a pump-generator
- CBT and Fry-Ark are “Trans-mountain Diversion Systems”

## Big Horn River Basin

- Boysen				  15 MW
- Buffalo Bill			  18 MW
- Heart Mountain		    5 MW
- Pilot Butte			    2 MW
- Shoshone 			    3 MW
- Spirit Mountain		    5 MW
- Yellowtail			125 MW
- (Yellowtail total is 250—1/2 plant is marketed by Pick Sloan-Eastern Division)

## North Platte River

- Alcova				41 MW
- Fremont Canyon		67 MW
- Glendo				38 MW
- Guernsey			  6 MW
- Kortes				36 MW
- Seminoe			52 MW
- Glendo and Guernsey generate only during summer season

## Colorado Big Thompson

- Big Thompson		  5 MW
- Estes 				45 MW
- Flatiron				95 MW
- Green Mountain		26 MW
- Mary’s Lake			  8 MW
- Pole Hill				38 MW
- Flatiron includes one 9 MW pump-generator
- Big Thompson generates only during runoff

## Fryingpan—Arkansas 

- Mount Elbert Pump-Generator
- 206 MW: one 100 MW unit
-         and one 106 MW unit
- Pumping requirement 132 MW per unit

## Limited System Capability

- RMR manages the power system on a  efficient, tightly controlled water system
- Numerous Water and Operational limitations
- Most water schedules change daily
- End-of-day elevation targets are critical
- In several cases, one reservoir serves as the afterbay for one plant and the forebay for the next

## Plant Characteristics

- Average annual inflow for entire  system is less than 5,000,000 acre-feet
- Eight plants capable of regulating
- Alcova, Fremont Canyon, Kortes (limited), Seminoe, Yellowtail, Estes, Flatiron, Mt Elbert
- Ability to regulate is governed by water schedules
- Only plant with day-to-day flexibility is Mount Elbert

## Slide 11

## Plant Limitations

- Examples of specific plant limitations:
- Alcova:  fluctuations limited to +/- 1 foot
- Yellowtail:  2 units have rough zones between 14 and 42 MW
- Fremont Canyon: during runoff units are often block-loaded at full output and additional river flow is bypassed
- Flatiron afterbay active storage is less than 400 acre-feet

## Other Restrictions

- Flow related:
- Estes:  runoff conditions make generation and regulation unpredictable
- Kortes: Miracle Mile fishing releases
- Environmental:
- Yellowtail:  Nitrogen super-saturation
- Fremont Canyon: ESA minimum releases

## Loveland Area Projects Marketing Plan

- Developed 1981 to 1985
- Implemented October 1, 1989
- Combined Pick-Sloan—Western Division and Fryingpan-Arkansas Projects
- LAP power is delivered to 180 preference customers, including 60 Coops, 85 municipals and 6 Tribes
- Contracts terminate 9/30/2024

## Determination of Marketable Resource

- Capacity—90% Probability of Exceedance for Pick-Sloan Generation
- Log-Pearson statistical analysis
- Plus installed capacity of Mt Elbert
- Represents higher level of risk
- Customers agreed to assume risk of difference  between 90 and 99% probability
- Either purchase or reduced CROD

## Determination of Marketable Resource

- No capacity was set aside for losses or regulation
- Assumed that diversity would be adequate
- Energy—Long Term Average
- 40-50 Year averages for most plants
- Minimum generation levels:
- Vary by month
- 17 to 32 percent

## Pumped Storage Feature

- Used to supplement LAP firm schedules
- Combined hourly Schedule of Firm and Pumped-Storage can not exceed monthly entitlement
- Off-peak Pump-back requirement is 1.4:1
- Mt Elbert is trapped on XCEL system
- Losses increase payback to about 1.6:1

## Pumped Storage Energy Account

- Pumped-Storage Energy Account
- Summer 3.9 kwh/kw of CROD
- Winter    4.4 kwh/kw of CROD
- Example:  Customer with 100 MW CROD can call on 390 or 440 MWh of energy before having to “repay” it
- Account can not go below 0 or above 100% and must be full at season-end

## Resource Available

**Summer (MW)**
- April           611
- May            561
- June           664
- July            713
- August        628
- September  607

**Winter (MW)**
- October	   610
- November  600
- December  654
- January     636
- February    594
- March        538

## Firm Customer Use

- Firm Customers options
- Firm Power
- Pumped Storage Option
- During 2003 Summer Season
- On-peak: 7 out of 10 hours customer usage consumes all marketed capacity
- Assumes customers schedule minimum during off-peak hours

## Total System Use

- In addition to Customer Use RMR must carry reserves: Reserve Pool requirement is 40 MW
- Western has calculated a need for 75 MW for regulation and ramping
- 55 MW is LAP responsibility
- Adding these requirements increases number of hours at full capacity to 80% in Summer 2003

## Off-Peak Requirements

- Customers typically schedule minimums or slightly above (except daytime Sundays)
- Minimum stream flows must be accommodated
- Mount Elbert is in pump mode—not available for regulation
- Meeting negative regulation needs is often harder than meeting the positive side

## Current Resource Integration Obligations

- Hydro-thermal Integration:
- Laramie River Station (1,100 MW)
- since 1981; contract term: 2029.
- Regulation Exchange:
- RMR provides regulation in exchange for fixed price firm energy purchase thru 2008

## Conclusion

- RMR operates a system approaching or exceeding maximum capability
- Capacity obligations already assume moderate to high level of risk
- Obligations:
- Firm and Project use power
- Control Area requirements
- Existing contractual requirements

## Conclusion

- From a resource management perspective:
- How much more can RMR’s resource handle?
- How does LAP acquire additional resources to meet control area needs?
- How should additional costs be allocated?