1. The document discusses improving hydropower reservoir operation at the Kemano system in British Columbia by using snow-related information. The system has conflicting objectives around maximizing revenue, minimizing flood impact, and supplying power to aluminum smelters. 2. Simple single-objective operating policies are not effective due to these conflicts. A multi-objective modeling approach was used to generate Pareto fronts and identify optimal reservoir trajectories. 3. Snow data on water content is important input for the model to accurately anticipate future inflows and better balance the objectives. The approach has been implemented at Rio Tinto Alcan to improve reservoir management.

1. Improving hydropower reservoir operation by using snow-related information
Improving hydropower reservoir operation by using snow-related
information
Desreumaux Quentin
Sherbrooke University - Rio Tinto Alcan
10th December - Como
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

2. Improving hydropower reservoir operation by using snow-related information
1 Kemano system
System
Hydrology
2 Modeling
Objectives and constraints
Modeling choices
Snow Data
3 Operating Policy
Basic Policy
Pareto Fronts
Hypervolume
Reservoir Trajectory
4 Conclusion
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

3. Improving hydropower reservoir operation by using snow-related information
Kemano system
Section 1
Kemano system
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

4. Improving hydropower reservoir operation by using snow-related information
Kemano system
System
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

5. Improving hydropower reservoir operation by using snow-related information
Kemano system
System
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

6. Improving hydropower reservoir operation by using snow-related information
Kemano system
System
• Installed power capacity of 865 MW
• Watershed of 14000 km2
• Turbined water goes to ocean
• Spilled water inland to Cheslatta Lake
• Cheslatta Lake outflow is uncontrolled
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

7. Improving hydropower reservoir operation by using snow-related information
Kemano system
System
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

8. Improving hydropower reservoir operation by using snow-related information
Kemano system
Hydrology
High inter-seasonal variability due to snow-melt
Figure: Inflows (median, 0.05 and 0.95 quantiles)
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

9. Improving hydropower reservoir operation by using snow-related information
Kemano system
Hydrology
Figure: Snow at 1300m high in Kitimat
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

10. Improving hydropower reservoir operation by using snow-related information
Kemano system
Hydrology
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

11. Improving hydropower reservoir operation by using snow-related information
Modeling
Section 2
Modeling
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

12. Improving hydropower reservoir operation by using snow-related information
Modeling
Objectives and constraints
Mid-term optimization (1 year)
Objectives :
• Maximize revenue from electricity exportation
• Minimize flood impact at Vanderhoof
• Minimum power must be supply to the aluminium smelters
Constraints :
• Minimum and maximum volume
• Maximum flow rate due to physical limits both for powerhouse and spillway
• Minimum spilled rate with respect to environmental constraints
• Keep constant outflow when rivers are frozen
• Cool down the river downstream
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

13. Improving hydropower reservoir operation by using snow-related information
Modeling
Objectives and constraints
Mid-term optimization (1 year)
Objectives :
• Maximize revenue from electricity exportation
• Minimize flood impact at Vanderhoof
• Minimum power must be supply to the aluminium smelters
Constraints :
• Minimum and maximum volume
• Maximum flow rate due to physical limits both for powerhouse and spillway
• Minimum spilled rate with respect to environmental constraints
• Keep constant outflow when rivers are frozen
• Cool down the river downstream
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

14. Improving hydropower reservoir operation by using snow-related information
Modeling
Modeling choices
Time step : 3 days
• Respect flow delay (reservoir → lake & lake → Vanderhoof)
• Shorter than flood period
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

15. Improving hydropower reservoir operation by using snow-related information
Modeling
Modeling choices
Time step : 3 days
• Respect flow delay (reservoir → lake & lake → Vanderhoof)
• Shorter than flood period
Aggregated command with priority rule (MEF, electric production, spill)
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

16. Improving hydropower reservoir operation by using snow-related information
Modeling
Modeling choices
Time step : 3 days
• Respect flow delay (reservoir → lake & lake → Vanderhoof)
• Shorter than flood period
Aggregated command with priority rule (MEF, electric production, spill)
Optimization algorithms :
• Stochastic dynamic programming
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

17. Improving hydropower reservoir operation by using snow-related information
Modeling
Modeling choices
Time step : 3 days
• Respect flow delay (reservoir → lake & lake → Vanderhoof)
• Shorter than flood period
Aggregated command with priority rule (MEF, electric production, spill)
Optimization algorithms :
• Stochastic dynamic programming
• (Direct Policy Search)
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

18. Improving hydropower reservoir operation by using snow-related information
Modeling
Snow Data
• Real-time measure (hourly)
• Snow water equivalent ≈ quantity of water
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

19. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Section 3
Operating Policy
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

20. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

21. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export :
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

22. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

23. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Minimize flood impact :
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

24. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

25. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Supply to the smelter :
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

26. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Supply to the smelter : ⇒ use the minimum required
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

27. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Use it right now !
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Supply to the smelter : ⇒ use the minimum required
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

28. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Use it right now !
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Waste it right now !
Supply to the smelter : ⇒ use the minimum required
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

29. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Use it right now !
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Waste it right now !
Supply to the smelter : ⇒ use the minimum required
Keep as much as possible for later on !
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

30. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Use it right now !
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Waste it right now !
Supply to the smelter : ⇒ use the minimum required
Keep as much as possible for later on !
⇒ Conflicting objectives !
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

31. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Use it right now !
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Waste it right now !
Supply to the smelter : ⇒ use the minimum required
Keep as much as possible for later on !
⇒ Conflicting objectives !
Smart policy ?
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

32. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Basic Policy
Simple mono-objective policies
Maximize revenue from electricty export : ⇒ if I get water, I turbine it
Use it right now !
Minimize flood impact : ⇒ empty the reservoir with a limited outflow
Waste it right now !
Supply to the smelter : ⇒ use the minimum required
Keep as much as possible for later on !
⇒ Conflicting objectives !
Smart policy ?
Spill only to avoid later flood. Turbine to the maximum excepted if you will not be
able to supply the minimum power in the future.
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

33. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Pareto Fronts
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

34. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Pareto Fronts
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

35. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Pareto Fronts
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

36. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Pareto Fronts
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

37. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Hypervolume
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

38. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Hypervolume
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

39. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Hypervolume
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

40. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Hypervolume
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

41. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Reservoir Trajectory
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

42. Improving hydropower reservoir operation by using snow-related information
Operating Policy
Reservoir Trajectory
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

43. Improving hydropower reservoir operation by using snow-related information
Conclusion
Section 4
Conclusion
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

44. Improving hydropower reservoir operation by using snow-related information
Conclusion
• This tool is used at Rio Tinto Alcan
• Real life problem : conflicting objectives
• Anticipate the future is the key for an effective management
• For this system, snow information is necessary to get a good operating policy
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

45. Improving hydropower reservoir operation by using snow-related information
Conclusion
• This tool is used at Rio Tinto Alcan
• Real life problem : conflicting objectives
• Anticipate the future is the key for an effective management
• For this system, snow information is necessary to get a good operating policy
• Ongoing works : truly multi-objective method
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

46. Improving hydropower reservoir operation by using snow-related information
Conclusion
• This tool is used at Rio Tinto Alcan
• Real life problem : conflicting objectives
• Anticipate the future is the key for an effective management
• For this system, snow information is necessary to get a good operating policy
• Ongoing works : truly multi-objective method
• Future works : include climatic information such as El Nino
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

47. Improving hydropower reservoir operation by using snow-related information
Conclusion
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin

48. Improving hydropower reservoir operation by using snow-related information
Conclusion
Questions ?
Improving hydropower reservoir operation by using snow-related information Desreumaux Quentin