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Power Resource Management

with assistance of

Kevin Gawne

Karl Reznichek

and

Dave Cormie

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Basics of Hydroelectric Generation

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Hydroelectric Generating Station

Flow

Forebay

Tailrace

Powerhouse

Dam

Spillway

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Cross Section of a Typical Hydro Unit

Forebay

Tailrace

Generator

Hea

d (H

)

Flow (Q)

Efficiency (e)

Power = Flow x Head x efficiency x constant

Turbine

Vertical Axis

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Introduction toManitoba Hydro System

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Alberta ManitobaSaskatchewan

Minnesota

North Dakota

Montana

South Dakota

SaskatchewanNelson River Local

Upper Churchill

Red

Lower Churchill

Winnipeg

Nelson and Churchill River Drainage Basins

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HVdc

System MapTotal Installed Capacity 5480 MW

Jenpeg

SelkirkBrandon

Grand Rapids

Limestone

Long SpruceKettle

Laurie River

Kelsey

Pine FallsGreat FallsMcArthur FallsSeven SistersPointe du BoisSlave Falls

LakeWinnipeg

Southern Indian Lake

Split L.

Stephens L.

70% of Capacity on Lower Nelson River: - Kettle (1232 MW) - Long Spruce (1023 MW) - Limestone (1330 MW)

Jenpeg

Cross Lake

Kiskitto Lake

Kisk

ittog

isu

Lake

Playgreen Lake

PlaygreenLake

Cross Lake

Norway House

Warren LandingLake Winnipeg

2-Mile Channel

8-Mile Channel

OminawinBypass

N

Nelso

n R W

est

Channel

Nel

son

R E

ast

Cha

nnel

•

•

•

Lake Winnipeg Regulation

More than 90%Hydraulic Based Generation

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Interconnected Transmission System

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Candidate Plants

- Wuskwatim (200 MW)

- Gull (630 MW)

- Conawapa (1400 MW)

Potential NewGenerationand HVdc

Winnipeg

Wuskwatim

Gull

Conawapa

New HVdc

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Variability of Hydraulic Supply(inflows measured as energy equivalent)

0

5

10

15

20

25

30

35

40

45

50

55

1920 1930 1940 1950 1960 1970 1980 1990 2000

An

nu

al E

ne

rgy

in T

Wh

Last 12 Months of Inflows(Feb 1, 2003 to Jan 31, 2004)

1940/1941 Drought

Manitoba Consumption

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Wet: Winnipeg River June 8-10, 2002 Precipitation

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Wet …

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Wet: June 2002Upper English River at Sioux Lookout

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Wet: Spill at Pointe du Bois, 2002

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Dry: Winter 02/03 Precipitation% of normal

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Dry: Lake of the Woods, 2003

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Flow Forecasting

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Load Forecasting

Load is related to time of year, day of week, hour of day, temperature, other

Manitoba LoadTuesday 9 am

1500

1750

2000

2250

2500

2750

3000

3250

3500

3750

4000

-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35

Temperature in C

Lo

ad in

MW

Heating CoolingHeating Cooling

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Market Forecast

YEAR

2001200019991998 19971996 1995

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WINTER WINTERSUMMER

DEMAND

WATERSUPPLY

DEMAND

SU

PP

LY

AN

D D

EM

AN

D

Water Supply &Manitoba Electrical Demand

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Manitoba and Export Demand(a typical week)

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

MW

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

EXPORT

Real Time

Day Ahead

Forward

Manitoba

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Power Resource Management

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Power Resource Management

• Manage Manitoba Hydro’s system of reservoirs, hydro stations, thermal stations, and tielines in the most economic and secure manner possible

• Meet or exceed regulatory requirements• Consider environment and waterway users

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- domestic load- exports- outages- losses

- inflows, storage, coal, gas- imports- plant capability

UncertaintyLicences

Social and Environmental

Power Resource Management

SUPPLY DEMAND

Resource ManagementDecisions

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Decisions

• Hydraulic stations (generate or spill?)• Thermal stations (generate?)• Reservoirs (store or release?)• Energy (buy or sell?)

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Uncertain Aspects

• Inflows into reservoirs• Manitoba load• Ice effects on river hydraulics• Export/import market prices• Thermal fuel costs

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Key Resource Management Decision -Lake Winnipeg Outflow

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Decision Considerations

• Multi-stakeholder– e.g. Lake of the Woods

• Multi-jurisdictional– Saskatchewan R. (AB, SK, MB)– Winnipeg R. (USA, ON, MB)

• Environment• Transportation• Recreation

Addressed through: • Boards, Licences, Agreements,

Programs, Facilities, Operating Guidelines

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System ModelRat Rapids DamLake St. Joseph

Lake St. Joseph * 1.00

Lac Seul Local * 1.00English River * 1.00

Sturgeon R. at McDougall * 1.00

Chukuni River * 1.00Trout Lake River * 1.00

Cedar River * 1.77Ear Falls Adjustment * 1.00

Cedar River * 2.62Wabigoon River * 1.00

Long Legged River * 1.00

Sturgeon R. at Salveson * 0.64

Sturgeon R. at Salveson * 1.63

Sturgeon R. at Salveson * 1.46

Whiteshell River * 2.69

Bird River * 1.00Whitemouth River * 1.00

Whiteshell River * 2.43

Bird River * 1.14

Assiniboine River * 0.00Berens Pigeon Rivers * 1.25

Bloodvein River * 1.00Fairford River * 1.00Gunisao River * 2.18

Lake Winnipeg Local * 1.00Poplar River * 1.38

Red River at Lockport * 1.00Kettle River * 3.23

Kettle River * 1.07

Kettle River * 0.99

Odei River * 1.54Grass River * 1.00Kettle River * 0.84Split Lake Adj. * 1.00

Burntwood River* 1.00

Upper Nelson RiverAdjustment * 0.495

Gunisao River * 1.012Upper Nelson RiverAdjustment * 0.505

Laurie River * 1.00Lac La Croix * 1.00

Namakan Lake Local * 1.00

Rainy Lake Local * 1.00

Lake of the WoodsLocal * 1.00

Sturgeon R. at Salveson * 0.96

Saskatchewan River * 1.00Saskatchewan River Local * 1.00

Lac La Croix

Namakan River

Namakan Lake

Kettle Falls

Rainy Lake

Fort Frances

Lake of the Woods

Norman Dam

Sand Lake

Whitedog Falls Spillway

Whitedog FallsPowerhouse

Caribou FallsSpillway

Pointe du Bois Forebay

Pointe du Bois

Slave Falls Forebay

Slave Falls

Natalie Lake

Seven Sisters

Lac Du Bonnet

McArthur

Great Falls Forebay

Great Falls

Pine Falls Forebay

Pine Falls

Cedar Lake

Grand Rapids

Hudson Bay

Limestone

Limestone Forebay

Long Spruce

Long Spruce Forebay

Kettle

Stephens Lake

Split Lake Outlet

Split Lake

Kelsey Forebay

Kelsey

ThompsonSeaplane Base

BurntwoodRiver

Sipiwesk Lake Outlet

Sipiwesk Lake

Cross Lake Outlet

Cross Lake

Jenpeg

Jenpeg Forebay

Nelson West ChannelNelson EastChannel

Lake Winnipeg

Laurie River Forebay Laurie River

HERMESManitoba Hydro System Hydraulic Schematic

EMMA

LEGEND

Generating Station

Lake Inflow

Outlet

Control

Lake

Pakwash Lake

Manitou FallsPowerhouse

Manitou FallsSpillway

Ball Lake

Ball Lake Outlet

Separation Lake

Separation Lake Outlet

Umfreville Lake

Caribou Falls Powerhouse

Root River Dam

Lac SeulEar Falls

Wpg. River Adj. * 1.00

Rev. No. Date File Name

1 2003/10/07 MH_System_HERMES_Schematic.ppt

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System Model

• Decision variables

• reservoir storage (STt), • turbine release (Rt), • spill (St) • produced energy (HEs,t), • imported energy (IEs,t), and • exported energy (EEs,t).

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System Model

, , , , , ,( s t s t s t s t s t s t t t T Tt s

Maximize HC HE EB EE IC IE SC S B ST

• Objective function

HCs,t - the hydro energy production cost; EBs,t - the export energy benefit;ICs,t - the import energy cost; SCt - the cost of spilling water; and BT - the benefit from saving the water for future

production.

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System Model

• Nonlinear hydro production function

• Linearized by assuming a constant value for the head (H) and efficiency (e).

• Iterative Linear Programming optimization

( , )E Q H t e Q H

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System Model

• Other constraints– Flow continuity

– Tieline load

– Supply and demand

1t t t t tST ST R S I

, ,

,( )s t s t

s t t

IE RATIO EML

IEF EEF EE EEF DPS

, , , , ,s t s t s t s t t s tHE IE EE L DPS W

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System Model

– Minimum storage

– Maximum storage

– Hydro energy relation to release

ˆ( , )t t tST MAX STMIN ST VARYMX

ˆ( , )t t tST MIN STMAX ST VARYMX

,( ) ( ) 0s t t ts

HE ERF STMAX R

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System Model

• Linear Programming Optimization– 100’s of decision variables– 1,000’s of constraints– 1,000,000’s of dollars benefits for the utility and

residents of Manitoba• Optimal use of power resource• Taking advantage of the system structure• Taking advantage of energy market

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