Reserved flow at the foot of large dams and green electricity Vincent Denis MHyLab Switzerland
www.mhylab.com
1st October 2009 08/02/13
1
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
2
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
3
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
5
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
08/02/13
6
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
7
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)
08/02/13
8
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
9
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
10
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
08/02/13
11
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
08/02/13
12
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.
08/02/13
13
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
14
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
08/02/13
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
16
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
08/02/13
17
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. 08/02/13
18
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
19
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
20
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
08/02/13
21
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 ! 08/02/13
22
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 ?
08/02/13
23
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
24
3 Swiss examples of ongoing large hydropower plants reserved flow turbining projects
08/02/13
25
Montsalvens dam, Broc Hydro power plant – Fribourg - CH – Groupe E
Gross Head = 122 m Electric power = 30 MW New requested Qr = 500 l/s
08/02/13
26
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
08/02/13
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
27
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
28
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)
08/02/13
29
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)
08/02/13
30
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
08/02/13
31
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
32
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
33
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
08/02/13
34
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
35
Le Day dam, Romande Energie SA, CH Les Clées (VD) power plant - 27 MW – Montcherand (VD) power plant – 14 MW -
08/02/13
36
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
08/02/13
37
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
38
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. 08/02/13
39
Conclusion RESERVED FLOW TURBINING SHOULD BE ENCOURAGED AND PROMOTED BY THE AUTHORITIES AND THE ENVIRONMENTALISTS !
08/02/13
40