1 / 40

Agenda of the presentation

Reserved flow at the foot of large dams and green electricity Vincent Denis MHyLab Switzerland www.mhylab.com 1 st October 2009. Agenda of the presentation. Small hydro in Switzerland – Production, Laws and directives Impact of the reserved flow on the Swiss production

bina
Download Presentation

Agenda of the presentation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Reserved flow at the foot of large dams and green electricityVincent DenisMHyLabSwitzerlandwww.mhylab.com1stOctober 2009

  2. 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

  3. 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 DZ

  4. YearlySwisselectric power production in GWh (2007)

  5. YearlySwissHydropower production

  6. Swisshydropower production vs national consumption

  7. Renewableelectricity production - 2007 (GWh/year)(Large hydro not included) Small hydro : 77. 18 % of the renewable electicity generation 9.27 % of hydro electricity generation 5.11 % of electricity generation According to Swiss Federal Office for Energy

  8. Main SwissLawsdealingwithsmall hydro Federal Law on Hydraulic forces (1916) Federal Energy Law (1998) Federal Law on the electricity supply (2007) Federal Law on water protection (1991)

  9. 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

  10. 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 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)

  11. 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

  12. 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

  13. 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.

  14. Federal law on water protection – Q347 Q347 = 1’350 l/s

  15. Federal law on water protectionArt. 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

  16. Federal law on water protection – Reserved flow Q347 = 1’350 l/s => Qr = 280 l/s + (1350 l/s – 500 l/s)/100 x 31 l/s = 544 l/s Q347 = 1’350 l/s

  17. 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

  18. 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.

  19. 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

  20. Impact of the reserved flow in terms of hydropower production Hydropower production forecast according to the Swiss utilities association (AES)

  21. 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

  22. 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 !

  23. 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 ?

  24. What are the constraint of a reserved flow 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

  25. 3 Swiss examples of ongoing large hydropower plants reserved flow turbining projects

  26. Montsalvens dam, Broc Hydro power plant – Fribourg - CH – Groupe E Gross Head = 122 m Electric power = 30 MW New requested Qr = 500 l/s

  27. Montsalvens dam Water level variation Max water level : 801 m Min water level : 775 m Downstream level : 759 m => Head : 16 to 42 m

  28. Montsalvens dam Head duration curve Average yearly head duration curve

  29. Montsalvens dam Turbine rotational speed and efficiency Turbine speed variation between 888 and 1441 rpm in function of the head variation.

  30. Montsalvens dam Turbine rotational speed and efficiency Turbine efficiency variation between 84.8% and 88.5 % in function of the head variation.

  31. Montsalvens damReserved 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

  32. 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

  33. Rossinière dam, Montbovonhydropower plant - 30 MW (Fribourg - CH) – Groupe E Gross Head = 89 m Electric power = 30 MW New requested Qr = 400 l/s

  34. 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

  35. 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

  36. Le Day dam, Romande Energie SA, CHLes Clées (VD) power plant - 27 MW –Montcherand (VD) power plant – 14 MW -

  37. Reserved flow turbiningLe 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

  38. 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: + 2’510 tonnes /year

  39. 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.

  40. Conclusion RESERVED FLOW TURBINING SHOULD BE ENCOURAGED AND PROMOTED BY THE AUTHORITIES AND THE ENVIRONMENTALISTS !

More Related