Agenda of the presentation

121/04/23

Reserved flow at the foot of large dams Reserved flow at the foot of large dams and green electricityand green electricity

Vincent DenisVincent DenisMHyLabMHyLab

SwitzerlandSwitzerlandwww.mhylab.comwww.mhylab.com

11stst October 2009 October 2009

221/04/23

Agenda of the presentationAgenda 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

321/04/23

Small hydro according to the Swiss LawSmall 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

421/04/23

Yearly Swiss electric power production in Yearly Swiss electric power production in GWh (2007)GWh (2007)

36'37326'344

3'199

Hydropower Nuclear power Thermal power

521/04/23

Yearly Swiss Hydropower productionYearly Swiss Hydropower production

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

En

erg

ie e

n G

Wh

Années

Production hydro-électrique en SuisseAnnées 1992 à 2007

Production annuelle

Production moyenne sur 10 ans

621/04/23

71.6%69.1%

79.3%

72.3%

78.6%

67.6% 66.1%62.5%

57.1% 56.3%

63.3%66.5%

64.3%

73.8%

67.2%

73.1%

62.9% 61.5%58.2%

53.1% 52.4%

58.9%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Pro

d. h

ydro

/Co

ns

om

ma

tio

n

Années

Part de l'Hydraulique relativement à la consommationAnnées 1997 à 2007

Cons.finale (sans pertes) Cons. Y compris pertes

Swiss hydropower production vs national Swiss hydropower production vs national consumptionconsumption

721/04/23

According to Swiss Federal Office for Energy

Renewable electricity production - 2007 (GWh/year)Renewable electricity production - 2007 (GWh/year)(Large hydro not included)(Large hydro not included)

PV; 23; 0.53% Biogas; 153; 3.50%

Wind; 14; 0.32%

Waste & wood; 807; 18.47%

Small hydropower; 3372; 77.18%

Small hydro :

77. 18 % of the renewable electicity generation

9.27 % of hydro electricity generation

5.11 % of electricity generation

821/04/23

Main Swiss Laws dealing with Main Swiss Laws dealing with small hydrosmall hydro

Federal Law on Hydraulic forces (1916)

Federal Energy Law (1998)

Federal Law on the electricity supply (2007)

Federal Law on water protection (1991)

921/04/23

Federal law on hydraulic forcesFederal law on hydraulic forces

• Definition of « official output » (small hydro or not)

• Definition of the water rights and licences

• Security of operation and responsibilities

1021/04/23

Federal Energy LawFederal 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 energiesin 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)

1121/04/23

Federal law on electricity marketFederal 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

1221/04/23

Federal law on water protectionFederal law on water protectionObjectives :

• 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

1321/04/23

Federal law on water protection – Federal law on water protection – Main articles dealing with Main articles dealing with

hydropowerhydropower

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.

1421/04/23

Federal law on water protection – QFederal law on water protection – Q347347

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

0 50 100 150 200 250 300 350

Dis

ch

arg

ge

in m

3/s

Nb de jours

Natural discharge of the river

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

0 50 100 150 200 250 300 350

Dis

ch

arg

ge

in m

3/s

Nb de jours


Q347 = 1’350 l/s

1521/04/23

Federal law on water protectionFederal law on water protectionArt. 31Art. 31

Minimal reserved flow :

For Q347 ≤ 60 l/s 50 l/sadditionnal reserved flow per 10 l/s 8 l/s

For Q347 ≤ 160 l/s 130 l/s additionnal reserved flow per 10 l/s 4.4 l/s

For Q347 ≤ 500 l/s 280 l/s additionnal reserved flow per 100 l/s 31 l/s

For Q347 ≤ 2’500 l/s 900 l/s additionnal reserved flow per 100 l/s 21.3 l/s

For Q347 ≤ 10’000 l/s 2500 l/s additionnal reserved flow per 1’000 l/s 150 l/s

For Q347 ≤ 60’000 l/s 10’000 l/s

1621/04/23

Federal law on water protection – Federal law on water protection – Reserved flowReserved flow

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

0 50 100 150 200 250 300 350

Dis

ch

arg

ge

in m

3/s

Nb de jours


Q347 = 1’350 l/s

Q347 = 1’350 l/s => Qr = 280 l/s + (1350 l/s – 500 l/s)/100 x 31 l/s = 544 l/s

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

0 50 100 150 200 250 300 350

Dis

ch

arg

ge

in m

3/s

Nb de jours


Usable discharge according to the Swiss Law

1721/04/23

Federal law on water protection – Federal law on water protection – Main articles dealing with Reserved Main articles dealing with Reserved

flowsflows

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

1821/04/23

Federal law on water protection – Federal law on water protection – Main articles dealing with Reserved Main articles dealing with Reserved

flowsflows

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.

1921/04/23

Impact of the reserved flow on the Impact of the reserved flow on the Swiss hydroelectric productionSwiss hydroelectric production

More than 200 dams in Switzerland

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

2021/04/23

Impact of the reserved flow in terms of Impact of the reserved flow in terms of hydropower productionhydropower production

Hydropower production forecast according to the Swiss utilities association (AES)

30000

31000

32000

33000

34000

35000

36000

37000

38000

39000

40000

1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070

Années

Pro

du

cti

on

an

nu

ell

e (

GW

h)

Débits résiduels

Référence : année 1996

Petites centrales hydrauliquesPotentiel final: 37'300 GWh

Nouvelles installations et modernisation des existantes

Potentiel résultant

2121/04/23


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

2221/04/23


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 !

2321/04/23

How to mitigate the production losses ?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 ?

2421/04/23

What are the constraint of a reserved flow What are the constraint of a reserved flow turbining project ?turbining project ?

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.

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

2521/04/23

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

projectsprojects

2621/04/23

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

Gross Head = 122 m

Electric power = 30 MW

New requested Qr = 500 l/s

2721/04/23

Montsalvens dam Montsalvens dam Water level variationWater level variation

Evolution du niveau d'eau amont de 1999 à 2005

778.00

780.00

782.00

784.00

786.00

788.00

790.00

792.00

794.00

796.00

798.00

800.00

802.00

00

.jan

v

10

.jan

v

20

.jan

v

30

.jan

v

09

.fé

vr

19

.fé

vr

29

.fé

vr

10

.ma

rs

20

.ma

rs

30

.ma

rs

09

.avr

19

.avr

29

.avr

09

.ma

i

19

.ma

i

29

.ma

i

08

.juin

18

.juin

28

.juin

08

.juil

18

.juil

28

.juil

07

.ao

ût

17

.ao

ût

27

.ao

ût

06

.se

pt

16

.se

pt

26

.se

pt

06

.oct

16

.oct

26

.oct

05

.no

v

15

.no

v

25

.no

v

05

.dé

c

15

.dé

c

25

.dé

c

Alt

itu

de

en

mè

tre

s

1999 2000 2001 2002 2003 2004 2005

Max water level : 801 m

Min water level : 775 m

Downstream level : 759 m

=>

Head : 16 to 42 m

2821/04/23

Montsalvens dam Montsalvens dam Head duration curveHead duration curve

Chutes nettes quotidiennes moyennes classées

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

31.0

32.0

33.0

34.0

35.0

36.0

37.0

38.0

39.0

40.0

41.0

42.0

43.0

0 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

Ch

ute

net

te (

m)

Moyenne 1999 2000 2001 2002 2003 2004 2005

29.0

29.5

30.0

30.5

31.0

31.5

32.0

32.5

33.0

33.5

34.0

34.5

35.0

35.5

36.0

36.5

37.0

37.5

38.0

38.5

39.0

39.5

40.0

40.5

41.0

41.5

42.0

0 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

Ch

ute

net

te (

m)

Average yearly head duration curve

2921/04/23

Montsalvens dam Montsalvens dam Turbine rotational speed and efficiencyTurbine rotational speed and efficiency

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

800

900

1000

1100

1200

1300

1400

1500

14 16 18 20 22 24 26 28 30 32 34 36 38 40 42

Chute nette (m)

Vit

es

se

de

ro

tati

on

(t/

min

)

3021/04/23

Montsalvens dam Montsalvens dam Turbine rotational speed and efficiencyTurbine rotational speed and efficiency

0.800

0.805

0.810

0.815

0.820

0.825

0.830

0.835

0.840

0.845

0.850

0.855

0.860

0.865

0.870

0.875

0.880

0.885

0.890

0.895

0.900

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)

Ren

dem

ent

turb

ine

(-) Turbine efficiency

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

3121/04/23

Montsalvens damMontsalvens damReserved flow turbining 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

3221/04/23

Montsalvens: production lossesMontsalvens: 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

3321/04/23

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

Gross Head = 89 mElectric power = 30 MWNew requested Qr = 400 l/s

3421/04/23

Rossinière dam Rossinière dam Reserved flow turbining 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

3521/04/23

Rossinière: production lossesRossinière: 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

3621/04/23

Le Day dam, Le Day dam, Romande Energie SA, CHLes Clées (VD) power plant - 27 MW –

Montcherand (VD) power plant – 14 MW -

3721/04/23

Reserved flow turbining Reserved flow turbining Le Day damLe 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

3821/04/23

Le Day dam: production lossesLe 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:

+ 2’510 tonnes /year

3921/04/23

Reserved flow turbiningReserved 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.

4021/04/23

ConclusionConclusion

RESERVED FLOW TURBINING SHOULD BE ENCOURAGED AND PROMOTED BY THE

AUTHORITIES AND THE ENVIRONMENTALISTS !

Agenda of the presentation

Documents

Transcript of Agenda of the presentation