The objective of this model is to demonstrate the optimization tool in GoldSim using a simple reservoir and hydropower model. The objective function is to maximize net revenues made from hydropower generation given extra capital costs to modify the system in 4 ways:
- Increase diversion capacity
- Increase outlet capacity
- Increase number of days hydropower releases
- Reduce the area of irrigated land
It is assumed that the payments on capital costs can be compared to annual power revenues on a dollar per acre-foot basis. The model starts with the assumption that no project will be built then tries to optimize the net power revenue by changing the combinations of possible projects. Inflows and outflows to/from the reservoir are defined with uncertainty. An irrigation demand calls for releases from the reservoir, which flow through the hydropower plant. Power releases (in addition to the irrigation releases) are made if it is determined there is enough water remaining in the reservoir for the remainder of the irrigation season. Some risk is inherent in this type of action because the inflows and outflows to/from the reservoir are not certain.
One major model constraint is supplying enough water for irrigation. A significant penalty cost is applied every day the irrigators are left short of water supply. The penalty increases as the number of shortage days increases. This penalty can be controlled in the Main Model Controls page. Other constraints consist of the reservoir operational and physical parameters, the existing capacities of the river diversion and hydropower plant. This model is simplistic in nature and does not represent a real system. It is assumed that a model of a real system of this nature would be significantly more complex.
This model is very simple compared to models that are required to simulate a real hydropower system but it effectively shows how optimization can be implemented in a water resources model using GoldSim.
GoldSim uses the Box Complex Method for optimization.