Western’s Use of GT-MAX Model

Western’s Use of the GT-MAX

Model

Sam Loftin - General Engineer

Western Area Power Administration -

CRSP CSC

Introduction

Discussion Topics

Overview of Western Area Power

Administration

Overview of the CRSP CSC

Overview of Glen Canyon Environmental

Process

Overview of Western’s customers and

contract arrangements

How we use the GT-MAX model

Long-term Replacement Power

Overview of Western

Area Power

Administration

Background

Western is an agency of the U.S.

Government, Department of Energy

Established in 1977 during energy crisis

to increase emphasis on energy

One of four Power Marketing

Administrations covering most of U.S

Multipurpose Water

Development Projects

Irrigation water storage and distribution

Hydroelectric Power Generation and

Transmission - revenue source

Flood Control

Recreation

Wildlife

Multipurpose Water


(Continued) Irrigation water storage and distribution

Multipurpose Water


(Continued) Hydroelectric Power Generation and

Transmission - revenue source

Multipurpose Water


(Continued) Flood control

Multipurpose Water


(Continued) Recreation

Multipurpose Water


(Continued) Wildlife

What Western does

Market Hydroelectric Generation - over

10,000 MW at 55 power plants

45,800 GWH energy sales and

$740,000,000 revenue last year

Deliver power over 27,123 km high

voltage transmission system

638 wholesale customers in 3.38 million

square km service area

Map of Western service area and

regions

Background of CRSP CSC

1,855 MW installed capacity

8,698 GWH energy and $176,000,000

revenue last year

3,843 km of high voltage transmission

line

125 wholesale customers

Firm power customers Salt Lake City Area Integrated Projects

CRSP CSC Power Resources

Glen Canyon Dam Capacity: 1356 MW

Generation: 6,626 GWh

Flaming Gorge Dam Capacity: 152 MW

Generation: 767 GWh

Morrow Point Dam Capacity: 156 MW

Generation: 366 GWh

Blue Mesa Dam Capacity: 96 MW

Generation: 296 GWh

Crystal Dam Capacity: 28 MW

Generation: 210 GWh

Fontenelle Dam Capacity: 13 MW

Generation: 79 GWh

Other Generation Resources

Upper Molina - 9 MW, 32 GWh

Lower Molina - 5 MW, 15 GWh

Elephant Butte - 28 MW, 109 GWH

Towaoc - 11 MW, 9 GWh

McPhee - 1 MW, 1 GWh

Deer Creek - 5 MW, 37 GWh

CRSP Transmission System

(map)

Glen Canyon and

Flaming Gorge

Environmental Processes

Endangered species

Bony Tail Chub

Colorado Squawfish

Humpback Chub

Razorback Sucker

(Photo of Grand Canyon Beach)

Changes in operations at

Glen Canyon Dam

Operational

Constraint

Historic Flows

(Pre-1991)

ROD Flows

(Post 1997)

Minimum release

(cfs)

3,000 summer

1,000 rest of year

8,000 - 7 am - 7 pm

5,000 at night

Maximum release

(cfs)

31,500 25,000

Daily fluctuations

(cfs/24 hrs)

28,500 summer

30,500 rest of year

5,000; 6,000; or 8,000

depending on release

volume

Ramp rate (cfs/hr) Unrestricted 4,000 up

1,500 down

Releases at Glen Canyon

Lost Capacity

Overview of Power Contracts

CRSP CSC share of customer load

averages about 25%

Cost of hydro power is generally much

less than other customer resources

CRSP CSC delivers whatever

hydropower is available based on

hydrological forecasts


(continued)

Hydro capacity is two-thirds of that

previously available

Available Hydro Power varies monthly

Power delivered at significantly higher

load factor

Total price paid by customers varies


(continued)

Customers have choice of replacing

remainder up to contracted amount

– Replace it themselves (purchase or self

generation)

– CRSP CSC replaces it on short term (6

months)

– CRSP CSC replaces it on long term (30+

months)

Available Hydro Power

Determination

Estimate available hydro power for upcoming

6 months from water forecasts using GT-MAX

Apportion power to each customer, notify

them, and find out their purchase needs

Determine purchases by CRSP CSC

Merchant Function

Water forecasts are updated monthly, so

hydropower forecasts updated monthly

Graph of one week output from

model July

Load vs. Generation

Case 18b (Load Sensitivity)

0

100

200

300

400

500

600

700

800

900

1,000

1,100

1,200

1,300

1,400

Sun Mon Tue Wed Thu Fri Sat

Day of Week

MW

Load

Generation

50% AHP

100% AHP

Non-Reimbursable

Expense Determination

Law allows power customers to not

repay costs for Glen Canyon test flows

Model “normal” operations without test

flows in GT-MAX

Compare revenue from “normal”

operations to actual operations

Difference in revenue is non-

reimbursable

Non-Reimbursable Expense

Determination (continued)

CRSP CSC modeled operation for

1993-1997

Determined difference between

“normal” and actual operations

Saved power customers $43 Million

between 1993 and 1997

CRSP CSC will also model any future

test flows

Upcoming Flaming Gorge and

Aspinall EIS

CRSP CSC will study changing operations at

Flaming Gorge and Aspinall

Compare cost of operational changes and

impact to power customers using GT-MAX

Use information from GT-MAX in negotiations

on preferred alternative

Preserve maximum generation/operational

flexibility possible

Long Term Replacement Power

Replace hydropower “lost” to

operational constraints on long term

Customers have choice of short-term,

long-term, or self replacement

Customers have choice of amount and

timing of replacement power


(continued)

RFP for supply and/or demand-side

resources

Evaluate costs quantitatively on a

uniform $/MWh basis

Evaluate non-cost factors qualitatively


(continued)

Use GT-MAX to model vendor

proposals integrated into CRSP CSC

power system

Determine optimum proposal(s) to

minimize purchase costs

Customers declined to participate in

long term replacement because of cost

CRSP CSC Merchant Function

Merchant Function schedules hydro

power resources to meet loads

Purchases from regional spot market

Sells surplus hydro power to spot

market

Looks for opportunities to buy and sell

at profit

CRSP CSC Merchant Function

(continued)

Use GT-MAX to optimize hydro power

operations (amount, location, timing)

Increase revenue, decrease purchase

costs, optimize limited hydro resource

Conclusion

Western has found many different uses

for GT-MAX in power system planning

and operations

GT-Max is well suited for analyzing

changes to operations at Hydro plants

and optimizing generation

Western’s Use of GT-MAX Model

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