HSAF Sacramento Operational issues Jon Ulrik Haaheim - Statkraft

Outline I. System Operation – Overview II. Scheme Classifications by head: low or high by storage capacity: run-of-river, reservoir or pumped-storage by purpose: single or multi-purpose by size: pico micro, mini, small, medium, large

III. Basic Hydropower Issues and Plant Components

IV. Water Management Strategies Basic challenges for reservoir management Adjusting to market demand page 2 STATKRAFT 2007

I) System Operation Overview page 3 STATKRAFT 2007

Another complex water system

Complex Storage Scheme: • 1 Major reservoir, contains water for multi-year production (in case of dry year(s)) • 34 intakes of streams plus 24 smaller reservoirs that are channelled in to the system • 3 Major Power plants (all underground), and 2 pumping stations

page 4 STATKRAFT 2007

◊ Saurdal Pumped storage plant , 2 x 160 MW Francis turbines + 2 x 160 MW Pump-turbines, 460 m head ◊ Kvilldal Power Station, 4 x 315 MW, 530 m head ◊ Hylen Power Station, 2 x 80 MW, 60 m head

Small but important water system

page 5 STATKRAFT 2007

II ) Scheme Classifications N.B. not mutually exclusive

a) by head: low or high b) by storage capacity: run-of-river, reservoir pumped-storage

c) by purpose: single or multipurpose d) by size: pico, micro, mini, small, medium, large

page 6 STATKRAFT 2007

Source: IEA Hydropower Agreement. 2000. Hydropower and the Environment . Vol.II p. 15-26

II a) by head : high or low

High head project with penstocks Tyssedal Power Plant, Western Norway UNESCO World Heritage site,

Low head project, Gaur scheme, Scotland, UK page 7 STATKRAFT 2007

II b) by storage capacity

Hydropower plant with reservoir (1,528 MW – 141,8 m head) Manic-5, Québec, Canada Run-of-river power plant (45MW) Rivières-des-Prairies, (head 7,5 m) Montreal, Canada Pumped storage power plant Goldisthal, Thüringen Germany page 8 STATKRAFT 2007

II c) by purpose: single or multipurpose Hoover Dam and Lake Mead (USA) host some 12 million visitors each year. The waters of Lake Mead are used to supply 18 million people in cities, towns and Indian communities in the states of Arizona, Nevada and California. In addition, agricultural land totalling 4,000 km2 in USA and 2000 km2 in Mexico is supplied with irrigation water, and the power plant supplies 4 billion kWh/year. page 9 STATKRAFT 2007

II d) by size pico micro mini small medium large

Chamuera, Rätia, Switzerland (0,55 MW) Macagua, Venezuela (15.910 MW) page 10 STATKRAFT 2007

definitions varying from country to country

< 0,005 MW < 0,1 MW 100 MW > 1000 MW

III ) Basic Hydropower Issues and Plant Components a) Working principles b) Main components of a hydropower plant c) Different heads require different types of hydraulic turbines d) Power output parameters: flow & head e) Plant efficiency f) page 11 STATKRAFT 2007

Operating modes

Working principles for hydropower

page 12 STATKRAFT 2007

Source: Renewable Energy. 2007. Illustration: Kim Brantenberg

Main components of a hydropower plant Transmission tower

Penstock

Generator

Valve

Turbine page 13 STATKRAFT 2007

Draft tube

Hydro Power Plant Electrical energy conversion Stator Rotor Mechanical energy conversion Vertical shaft Pelton turbine 4 Nozzles page 14 STATKRAFT 2007

Components

Bulb

High Head Francis

page 15 STATKRAFT 2007

Kaplan

Pelton

Large Francis

Generator

Hydropower schemes with storage capacity HIGH HEAD Pelton turbines

page 16 STATKRAFT 2007

Hydropower schemes with storage capacity

page 17 STATKRAFT 2007

MEDIUM HEAD Francis turbines Possibilities for pumped storage and gaining head

Hydropower schemes with upper storage LOW HEAD Kaplan & bulb turbines Often in cascade

page 18 STATKRAFT 2007

High head turbine: Pelton ( 300 - 2000 m)

Features Very high efficiency through new bucket and injector designs Runners milled out of solid casting or forging (“doghnut”), or from a monocast traditional runner Have supplied units up to 350 MW under 900 m head

page 19 STATKRAFT 2007

Low and Medium Head Francis (40 - 200 m head) Features Very High Efficiency X-Blade technology gives unsurpassed performance at off-design operation Variation in output (30 – 130 %) Variation in Head (60 - 130% head variation) Extreme cavitation resistance Sturdy bearing and operating mechanism design Very low pulsation levels at all operating points Have design for world largest Francis Units, 3G

page 20 STATKRAFT 2007

Kaplan (10 - 70 m head)

Features Very high efficiency Well proven runner operating mechanism, 70 years + experience Cavitation resistance achieved through innovative blade tip designs and stainless steel parts

page 21 STATKRAFT 2007

Typical types of hydropower turbines H(m)

High head – less water •Reservoir •Clean water / erosion •Normally long tunnels / penstocks

1000

Pelton turbines Medium •Run of river or reservoir •Clean water

500

Low head, much water

Francis turbines

•Run of river •Small or no reservoirs •Power station within the dam

100

Kaplan-, bulb-, propeller turbines 100

200 Q(m3/s)

page 22 STATKRAFT 2007

Efficiency for hydropower plants Generator-/transformer

100%

Tunnels, penstock

94%

Turbine

90%

El-mech

Efficiency (%)

Total efficiency

Optimum for operation Range of operation

Capacity, P(kW) or flow, Q(m3/s) page 23 STATKRAFT 2007

Hydropower Plant – Output and Production Output: P (W) = Q * Hb * g * ρ * η Flow (m3/s)

Efficiency, typically: Generator: 98% Turbine: 90-96% Water system: 90-98%

Head (m) g= 9,81

Totally: 85-90%

m/s2

ρ(water dencity) =1000 kg/m3

Calculation: Output: Production: page 24 STATKRAFT 2007

(η=87%)

P = Q * H * 8,5/1000 (MW) E = P * oper.time (h/1000) (GWh)

Hydropower Plant – Output and Production Micro 0,5 m3/s * 10 m * 9800 * 0,87 = 42 630 W Operating in 5000 hours

= 42,6 kW = 213 000kWh

Small 5 m3/s * 100 m * 9800 *0,87 = 4 263 000 W Operating in 5000 hours

= 4,263 MW = 21,3 GWh

Medium to large 100 m3/s *500 m * 9800 *0,87 = 426 300 000 W Operating in 5000 hours

= 426 MW = 2,13 TWh

Very large 5000 m3/s *100 m *9800*0,87 = 4 263 000 000 W Operating in 5000 hours

page 25 STATKRAFT 2007

= 4263 MW = 21,3 TWh

Operating modes Base load or peak load Ancillary services to provide grid stability Spinning and non-spinning reserve Regulation and frequency response Voltage support Black start capability

page 26 STATKRAFT 2007

Operating modes - frequency support Renewable back-up from hydro reservoirs facilitates the integration of more intermittent renewables into the electric system

page 27 STATKRAFT 2007

Hours of February 2001

18 :1 5

05 :1 5

16 :1 5

03 :1 5

14 :1 5

01 :1 5

12 :1 5

23 :1 5

10 :1 5

21 :1 5

08 :1 5

19 :1 5

06 :1 5

17 :1 5

04 :1 5

15 :1 5

02 :1 5

13 :1 5

100 000 90 000 80 000 70 000 60 000 50 000 40 000 30 000 20 000 10 000 0 00 :1 5

Power (kW)

Generation from 2 wind parcs in Quèbec, Canada (Cap Chat + Matane) = 100MW of installed capacity

IV) Water Management Strategy Simon East

page 28 STATKRAFT 2007

Reservoir management - the basic challenge Generation

Price

7000

6000

250

Max. Inflow 200

5000

Mean Inflow

4000

3000

2000

150

Consumption Min. Inflow

100

50 1000

0 page 29 STATKRAFT 2007

0

Operating ranges . . .

defined by license conditions

page 30 STATKRAFT 2007

Flow modulation given places

License can and may define; Upper reservoir level Lower reservoir level Seasonal reservor levels Minimum or specific flows at certain places Mitigations Obligations to deliver power Advisory Board regarding water management Test periods and research programs General obligation to comply with decisions from governmental agency in environmental matters page 31 STATKRAFT 2007

The Aura River. After 50 years the licence is under review. The local community wants the salmon back.

page side 32 STATKRAFT DETTE ER EN 2007 DUMMYTITTEL

Salmon catches in the Alta river Business rationale for environmental power generation:

Salmon in Alta, number and weight 1974-2002

Number 4 500

Sum kg 35 000

number

4 000

30 000

sum kg 3 500

Public acceptance for excellent water management Secure the long-term ownership and ”license to operate”.

25 000 3 000 2 500

20 000

2 000

15 000

1 500 10 000 1 000 500

5 000

Alta Powerplant commisioned 1987

0

page 33 STATKRAFT 2007

02 20

00 20

98 19

96 19

94 19

92 19

90 19

88 19

86 19

84 19

82 19

80 19

78 19

76 19

19

74

0

page 34 STATKRAFT 2007

New Tools

Using models for ecological gain

E

D

C

A F

G1

Characterizing the river according to river types and analyzing page 35 STATKRAFT 2007

900 800

Avoided Neutral Gunstig Preferred Nøytral

600 500 400 300 200 100 0 1

2

4

5

9 13 18 Vannføring [m3/s]

35

53

89

177

89

177

900

Vanndekket areal [m2

Avoided Neutral Preferred Dry

Vanndekket areal [m2

700

Research by SINTEF Energy AS and the Norwegian Institute for Nature Research indicates that more water don't necessary results in more or larger living areas

Dybde Depth

Ugunstig

800

Ugunstig Avoided

700

Neutral Nøytral

600

Preferred Gunstig

Hastighet Velocity

500 400 300 200 100 0 1

2

4

5

9

13

18

Vannføring [m3/s]

page 36 STATKRAFT 2007

35

53

The relevant power market Russia

Scandinavia Denm 350 TWh ark The 35 Netherland TWh s UK Belgi 110 TWh 410 TWh Germa Poland um. ny and 140 TWh 90 Luxemb Czech TWh ourg 50 TWh 550 France Swit TWh Austria 440 TWh z 60 TWh 60 Italy TW 320 TWh Spain h.

page 37 STATKRAFT 2007

Price formation - Illustration 40

Oil condensing and gas turbines

dry year

30

wet year

Variations in Average price in a dry year inflow provide for variations in prices

25 20

Various coal fired

Average spot price in a normal year

15

Various coal fired base and intermediate load

Average price in a wet year

10 CHP and Nuclear CHP Denmark 5

5 Wind and Hydropower

0 page 38 STATKRAFT 2007

Generation

Demand

Fundamental analysis as a basis for operational strategy Hydro Power System

8

Marginal Costs of other Generation

Relevant Market

Finnmark

7 Troms

30

9

Oil condensing II, Sweden 26

13

Oil condensing Light distillates, Sweden 24

25

Sveronor

6

Øre/kWh

Oil fuelled intermediate load, Denmark 21

20

Theoretical equilibrium price when competing at variable costs

Helgeland

Coal fired base load, Finland 18

Finland

Water Storage Power Stations Rivers/Tunnels Restrictions

Coal fired intermediate load / oil fuelled base load, Denmark 17 Coal condensing / oil condensing HFO, Sweden 17

15

10

Various coal fired base load, Denmark 13 - 16

5

Co-generation / CHP, Finland 11

10

Nuclear, Finland 9

Norgemidt

Nuclear / CHP, Sweden 7

4

CHP, Denmark 5

5

Vestmidt

Hydropower 2

1

0 20

40

60

80

100

120

140

*) Including taxes and duties depending on actual generation gh\MA\MC_eng.ppt

Svernnor

CHP = Combined Heat and Power

160

180

200

220

240

TWh/year

HFO=Heavy Fuel Oil

260

280

300

320

340

360

Reg1 nord

380

Total Demand 1995

Vestsyd

3

Svermidt

14

Transmission Lines

2 Sørland

Flexible Demand and Plant Availability

Sversyd 11

15

power exchange

Danmvest

• Interruptible consumption and

Danmost

respective trigger prices • Available thermal capacity

• Capacity both directions • Min. price differentials for • Losses

12

Hydrological Data Fixed Demand and Supply

• Domestic consumption and power intensive industries • Fixed supply contracts between areas

Power Exchange with other markets Modelled with different • Steps and delivery obligations page 39 STATKRAFT • Trigger values for spot exchange 2007

ANALYSIS AND RESULTS Parallel simulation for 70 years detailed inflow statistics. Price projections for the next 5 years based on 70 alternative inflow scenarios:

• Current storage level • Inflow statistics • Snow projections • System data

•Preparation of => Water values and optimum production plans => Probability distributions for future energy prices

Maintenance

• Maintenance plans • Degree of availability

Economical operation of reservoir Reservoir 1 (small)

Merit order different reservoirs based on individual water values

Current reservoir level (high)

Price forecast

Water Value Reservoir 1 (low)

Water Value Reservoir 2 (high)

Price

Future rainfall

Water Value Reservoir 1 (low)

future spot prices which depend on total inflow.

MW 0

Reservoir 2 (large) Future rainfall Current reservoir level (low) page 40 STATKRAFT 2007

Water Value Reservoir 2 (high)

Price forecasts

Reservoir Management Market analyses 8

90

7

Baseload Price

70

4 40 3

30

Generation forecasts

Jul-03

Jun-03

Apr-03

May-03

Mar-03

Jan-03

Feb-03

Dec-02

Nov-02

Oct-02

Sep-02

Jul-02

Aug-02

Jun-02

0 Apr-02

1

0 May-02

10 Mar-02

2

Feb-02

20

Jan-02

Euros per MWh

page 41 STATKRAFT 2007

5

Average Hourly Volum e

50

Consistent distributions

6

Peak Price

60

GWh per hour

80

1

250

5 00

0,8

2 00

4 00

0,6

150

3 00

0,4

1 00

2 00

0,2

50

1 00

0

0

0

Reservoir Management Governmental evaluation of different interests

Reservoir

License

HPS1

Other demands regarding Water levels or flows: • Biological / environmental • Agriculture • Water supply / quality • Flood protection • Transportation • Industrial • Leisure • etc.

page 42 STATKRAFT 2007

How to operate reservoirs optimally? Maximal energy output or economically? For one owner or for all owners? No generation required Commitment settled by other units in portfolio

HPS2 Other owners with other demands and commitments HPS3

HPS4 Different models for cooperation and utilization of the water resources.

Swedish model Capacity

Demand

Generation

Increased energy in reservoir

Owner 1

50

0

33

33

Owner 2

100

80

67

-13

Owner 3

150

120

100

-20

Sum

300

200

200

0

Only a matter of invoicing and settlement and keeping track of ”ownership” of energy in reservoir. Operation of watercourse must within technical limits. page 43 STATKRAFT 2007

Governance in operation • Institutional framework and policies • Ownership structure and models for cooperation • The role of the industry - Business vision and goals - Social responsibility and transparency - Business processes and procedures - Resource and asset management Guidance in management and daily operations for the company and its employees. Public confidence in the company in ”householding” natural resources of national interest (responsible stewardship). page 44 STATKRAFT 2007

Thank you for your attention!

page 45 STATKRAFT 2007