Long-Term Hourly Simulation of a Peaking Hydropower Project With Application to Federal Relicensing

摘要

Eugene Water & Electric Board's (EWEB) Carmen-Smith Hydroelectric Project includesrnthree reservoirs, two power plants, two bypassed river reaches, and operates primarilyrnas a peaking project. The reservoirs operate for diversion, storage, and reregulation ofrnthe peaking flows. The largest powerhouse operates in a peaking mode while the otherrnpowerhouse generates from the reregulated flows. A power study model wasrndeveloped to support Federal relicensing and to evaluate hydroelectric improvements tornthe project. To capture the essential characteristics of a peaking operation, an hourlyrntime increment of computation is necessary. From US Geological Survey flow records,rnit was possible to develop 42 years of continuous daily flows. Five years of generationrnrecords from the two power plants were used to develop generation scenarios as arnfunction of month and flow. This information combined with reservoir elevations andrnUSGS records formed the basis for the model calibration.rnMany hydroelectric peaking operations are evaluated with hourly models that cover arnweek, while many run-of-river projects are evaluated with spreadsheet daily flowrnduration models. To fully evaluate the long-term generation impact of potentialrnoperation changes that could be considered during relicensing, a FORTRAN powerrnstudy operation model was developed that simulated all of the 368,000 hours ofrnoperation over the 42-year period. The model has a run execution time of a fewrnseconds and creates separate files of tables of detailed monthly, daily, and hourlyrnoutput parameters, as well as data files for plotting. This paper highlights thernmethodology used to develop and calibrate a detailed long-term hourly hydroelectricrnpeaking model and the benefits of this type of hourly model in comparison to the morerncommonly used short-term hourly models and simplified daily spreadsheet models.rnA User's Manual was prepared and the compiled model was given to EWEB for furtherrnevaluation of relicensing scenarios. The model, data, and documentation were alsorntransferred to Agency personnel for their use. During license development andrnsettlement negotiations, EWEB used the model to evaluate changes to reservoirrnoperations, countless spill scenarios, and the value of peaking operations. The keyrnbenefit of a model that examines 42 years of information as well as having the ability tornevaluate hourly changes is that it allows the user to quickly evaluate costs over the longrnterm and assess how hourly operations may be affected. Potential future applicationsrnof the model could include evaluating the operating impacts of climate change.