/ESHA_MHyLab_091001_VD

Reserved flow at the foot of large dams and green electricity Vincent Denis MHyLab Switzerland

www.mhylab.com

1st October 2009 08/02/13

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Agenda of the presentation Small hydro in Switzerland – Production, Laws and directives Impact of the reserved flow on the Swiss production Turbining of reserved flows – technical constraints Turbining of reserved flow – Three examples 08/02/13

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Small hydro according to the Swiss Law Small hydropower plant : HPP with an output smaller than 10 MW The output is calculated according to the art. 51 of the Federal Law on hydraulic forces (1916) P = 10 x Qaverage x ∆Z 08/02/13

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Yearly Swiss electric power production in GWh (2007) 3'199

26'344

36'373

Hydropower 08/02/13

Nuclear power

Thermal power 4

Yearly Swiss Hydropower production Production hydro-électrique en Suisse Années 1992 à 2007 45000

40000

35000

30000

25000

h W iG rg e n E

20000 Production annuelle Production moyenne sur 10 ans

15000

10000

5000

0 1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

Années

08/02/13

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Swiss hydropower production vs national consumption Part de l'Hydraulique relativement à la consommation Années 1997 à 2007

90.0%

79.3%

80.0%

71.6% 70.0% 66.5% 60.0%

69.1%

78.6% 72.3%

73.8%

73.1%

67.6%

66.1%

64.3%

63.3%

62.5%

67.2% 62.9%

57.1%

61.5%

56.3% 58.9%

58.2% 50.0%

53.1%

52.4%

2005

2006

ti a m s n /C y .h d ro P

40.0% 30.0%

Cons.finale (sans pertes)

Cons. Y compris pertes

20.0% 10.0% 0.0% 1997

1998

1999

2000

2001

2002

2003

2004

2007

Années

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Renewable electricity production - 2007 (GWh/year) (Large hydro not included) PV; 23; 0.53%

Biogas; 153; 3.50%

Wind; 14; 0.32%

Small hydro : 77. 18 % of the renewable electicity generation 9.27 % of hydro electricity generation

Waste & wood; 807; 18.47%

Small hydropower; 3372; 77.18%

5.11 % of electricity generation According to Swiss Federal Office for Energy 08/02/13

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Main Swiss Laws dealing with small hydro Federal Law on Hydraulic forces (1916) Federal Energy Law (1998) Federal Law on the electricity supply (2007) Federal Law on water protection (1991)

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Federal law on hydraulic forces • Definition of « official output » (small hydro or not) • Definition of the water rights and licences • Security of operation and responsibilities 08/02/13

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Federal Energy Law • Objective : + 5’400 GWh of renewable energies by 2030 • Objective : + 2’000 GWh of hydropower by 2030 (base : 2000) • Access to the grid : Obligation to accept renewable energies in the grid, even if the production is not constant • Small hydro is renewable up to 10 MW • Renewables are supported by guaranteed feed-in tariffs (25 years for Hydro; decreasing tariff between ≈ 22 to 5 €cts/kwh) 08/02/13

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Federal law on electricity market • Definition of renewable energies (hydro, PV, geothermal energy, wind, biomass) • Definition of the grid access conditions for the renewables • Commercialization of the renewable electricity

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Federal law on water protection Objectives : •

To preserve human, animals and plants health

•

To guarantee the drinking and industrial water supply.

•

To promote a rational use of water.

•

To protect the natural and local biotopes

•

To protect the fishes

•

To protect the water streams as a part of the landscape

•

To ensure irrigation

•

To allow the use of the rivers and lakes for leisure

•

To ensure a “natural” hydrology

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Federal law on water protection – Main articles dealing with hydropower Art 31 : Reserved flows Q347 is considered as the calculation reference Q347 = natural discharge of a permanent water stream that is reached at least 347 days per year.

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Federal law on water protection – Q347 11.000 10.000 9.000 8.000

Natural discharge of the river

7.000 6.000 5.000

Q347 = 1’350 l/s

/ 3 m n e rg a h c is D

4.000 3.000 2.000 1.000 0.000 0

50

100

150

200

250

300

350

Nb de jours 08/02/13

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Federal law on water protection Art. 31 Minimal reserved flow : For Q347 ≤ 60 l/s additionnal reserved flow per 10 l/s

50 l/s 8 l/s

For Q347 ≤ 160 l/s additionnal reserved flow per 10 l/s

130 l/s 4.4 l/s

For Q347 ≤ 500 l/s additionnal reserved flow per 100 l/s

280 l/s 31 l/s

For Q347 ≤ 2’500 l/s additionnal reserved flow per 100 l/s

900 l/s 21.3 l/s

For Q347 ≤ 10’000 l/s additionnal reserved flow per 1’000 l/s

2500 l/s 150 l/s

For Q347 ≤ 60’000 l/s

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10’000 l/s 15

Federal law on water protection – Reserved flow 11.000 10.000 9.000 8.000 7.000

Q347 = 1’350 l/sNatural => discharge of the river Natural discharge of the river Qr = 280 l/s + (1350 – 500according l/s)/100 31 l/s Usablel/s discharge to thexSwiss Law= 544 l/s

6.000 5.000

Q347 = 1’350 l/s

D / 3 m n e rg a h c is

4.000 3.000 2.000 1.000 0.000 0

50

100

150

200

250

300

350

Nb de jours 08/02/13

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Federal law on water protection – Main articles dealing with Reserved flows Art 32 : Decrease of the reserved flow If derivation ≤ 1000m, altitude ≥ 1750 m and Q 347 ≤ 50 l/s If the river has no fishes and Qr ≥ 0.35 x Q347 In case of emergency for drinking water supply, irrigation water supply or firemen use Other special cases according to prior decision of the federal government

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Federal law on water protection – Main articles dealing with Reserved flows Art 33 : Increase of the reserved flow Weighting of interests ! Public interests, economic impact on the area, economic impact on the person asking for a license, energy supply. Landscape aspect, biodiversity, water quality, drinking and irrigation water supply.

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Impact of the reserved flow on the Swiss hydroelectric production More than 200 dams in Switzerland

http://www.swissdams.ch/swisscod/Dams/damtext/barragesuisses.asp 08/02/13

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Impact of the reserved flow in terms of hydropower production 40000

Potentiel résultant 39000

38000

Nouvelles installations et modernisation des existantes

Production annuelle (GWh)

37000

36000

Petites centrales hydrauliques

Potentiel final: 37'300 GWh

35000

34000

Référence : année 1996

33000

Débits résiduels 32000

31000

30000 1995

2000

2005

2010

2015

2020

2025

2030

2035

2040

2045

2050

2055

2060

2065

2070

Années

Hydropower production forecast according to the Swiss utilities association (AES) 08/02/13

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Impact of the reserved flow in terms of hydropower production The increase of the reserved flow (according to the 1991 Law) will lead to a total production losses of 2’500 GWh. In other words, the increase of small hydro production will only allow to compensate these losses. Considering the average European CO2 emission level of 480 t/GWh, these losses will « generate » 1’200’000 t/year. I do not want to say that every drop of water should be used

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Impact of the reserved flow in terms of hydropower production Of course, this comparison is a little bit provocative The goal is not to say that every drop of water should be used in order to generate electricity without taking into account the environment However, we should keep in mind the fact that the water protection can lead to an air pollution. It is essential to find a good compromise !

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How to mitigate the production losses ? The dam generally present a low to medium head between its foot and the water level of the reservoir. This head represent an energy that is lost if the reserved flow is “simply” rejected at the foot. Why not turbining this water and consequently reduce the production losses ?

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What are the constraint of a reserved flow turbining project ? ď ¸Generally, the head is not constant (function of the remaining water in the reservoir) => It could be necessary to operate the turbine at variable speed. ď ¸The reserved flow shall be kept constant as it is a legal value that is a part of the license => The turbine shall be regulated 08/02/13

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3 Swiss examples of ongoing large hydropower plants reserved flow turbining projects

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Montsalvens dam, Broc Hydro power plant – Fribourg - CH – Groupe E

Gross Head = 122 m Electric power = 30 MW New requested Qr = 500 l/s

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Montsalvens dam Water level variation Evolution du niveau d'eau amont de 1999 à 2005 1999

2000

2001

2002

2003

2004

2005

Max water level : 801 m

802.00 800.00 798.00

Min water level : 775 m

796.00

Downstream level : 759 m

792.00 790.00 788.00

=>

786.00 784.00

Head : 16 to 42 m

782.00

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25.déc

15.déc

05.déc

25.nov

15.nov

26.oct

05.nov

16.oct

06.oct

26.sept

16.sept

06.sept

27.août

17.août

28.juil

07.août

18.juil

08.juil

28.juin

18.juin

08.juin

29.mai

19.mai

29.avr

09.mai

19.avr

09.avr

30.mars

20.mars

29.févr

10.mars

19.févr

09.févr

30.janv

20.janv

778.00

10.janv

780.00

00.janv

Altitude en mètres

794.00

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ChuteChute nette nette (m) (m)

Montsalvens dam Head duration curve Chutes nettes quotidiennes moyennes classĂŠes

42.0 41.5 41.0 40.5 43.0 40.0 42.0 39.5 41.0 39.0 40.0 38.5 39.0 38.0 38.0 37.5 37.0 37.0 36.0 36.5 35.0 36.0 34.0 35.5 33.0 35.0 32.0 34.5 31.0 34.0 30.0 33.5 29.0 33.0 28.0 32.5 27.0 32.0 26.0 31.5 25.0 31.0 24.0 30.5 23.0 30.0 22.0 29.5 21.0 20.0 29.0

Moyenne

0

1999

2000

2001

2002

2003

2004

2005

10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360

Jours/an

Average yearly head duration curve 08/02/13

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Montsalvens dam Turbine rotational speed and efficiency 1500

Vitesse de rotation (t/min)

1400 1300

Turbine speed variation between 888 and 1441 rpm in function of the head variation.

1200 1100 1000 900 800 14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

Chute nette (m)

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Montsalvens dam Turbine rotational speed and efficiency 0.900 0.895 0.890 0.885 0.880 0.875

Rendement turbine (-)

0.870

Turbine efficiency variation between 84.8% and 88.5 % in function of the head variation.

0.865 0.860 0.855 0.850 0.845 0.840 0.835 0.830 0.825 0.820 0.815 0.810 0.805 0.800 14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

Chute nette (m)

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Montsalvens dam Reserved flow turbining

Design flow: 500 l/s Variable head: 16-42 m Electrical output: 160 kW Production: 1'250'000 kWh/year Consumption of 300 households

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Montsalvens: production losses Gross head: 122 m Reserved flow: 500 l/s Corresponding production: ~ 3’200’000 kWh/year SHP recovered production: 1'250'000 kWh/year Production loss: ~ 1’950’000 kWh/year (61%) Consumption of 500 households CO2 increase on the European interconnected grid: + 940 tonnes /year 08/02/13

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Rossinière dam, Montbovon hydropower plant - 30 MW (Fribourg - CH) – Groupe E

Gross Head = 89 m Electric power = 30 MW New requested Qr = 400 l/s 08/02/13

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Rossinière dam Reserved flow turbining

 Design flow: 400 l/s  Variable head: 10-16 m  Electrical output: 50 kW  Production: 390'000 kWh/year  Consumption of 100 households

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Rossinière: production losses Gross head: 89 m Reserved flow: 400 l/s Corresponding production: ~ 1’800’000 kWh/year SHP recovered production: 390'000 kWh/year Production losses: ~ 1’410’000 kWh/year (78%) Consumption of 350 households CO2 increase on the European interconnected grid: + 680 tonnes /year 08/02/13

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Le Day dam, Romande Energie SA, CH Les Clées (VD) power plant - 27 MW – Montcherand (VD) power plant – 14 MW -

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Reserved flow turbining Le Day dam

 Reserved flow: 300 l/s + 600 l/s  Variable head: 14 - 25 m  Electrical output: 100 kW  Production: 560'000 kWh/year  Consumption of 140 households

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Le Day dam: production losses Gross head: 176 m for les Clées, 104 m for Montcherand Average reserved flow: 400 l/s Corresponding production: ~ 5’790’000 kWh/year SHP recovered production: 560'000 kWh/year Production loss: ~ 5’230’000 kWh/year (90%) Consumption of 1050 households CO2 increase on the European connected grid: 08/02/13

+ 2’510 tonnes /year

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Reserved flow turbining This possibility tends to an optimal use of resources as : It mitigates the effects of an increase of the reserved flow on the electricity production and on CO2 emissions. It uses an existing infrastructure It allows a strict respect and an easy check of the reserved flow It has strictly no negative impact on the environment.

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Conclusion RESERVED FLOW TURBINING SHOULD BE ENCOURAGED AND PROMOTED

BY THE AUTHORITIES AND THE ENVIRONMENTALISTS !

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