Coupling of hydrological and hydraulic simulation models with numerical optimization algorithms has proven to be effective for optimizing operations of reservoir systems with respect to different management objectives. The combination of accurate reservoir inflow forecasting and optimization technology can provide more efficient balanced solutions for multi-purpose operations of reservoir systems and thereby improve the economy of hydropower production. The technology can be used for both long-term planning purposes for deriving optimal operation rule curves and for short-term water management and hydro scheduling. The forecasting and optimization system is established within a decision support system for real-time operation.The developed forecasting and optimization technologies are demonstrated on optimization of the Hoa Binh reservoir in Vietnam considering hydropower production and flood control. Optimization of reservoir operation rules provides optimal solutions that have both a smaller flood risk and a larger hydropower potential compared to the present regulations. Simulations with a balanced optimum solution show a substantial increase of hydropower production of 210 million kWh on average per year. Real-time optimization in normal flow situations provides solutions that trades-off the immediate and the future value of hydropower production. In flood situations, inflow forecast information is used to optimize reservoir releases to meet storage requirements to reduce downstream flooding.
With the recent and continuing increases in energy consumption, combined with strong environmental concerns, there has been a resurgence in the development of low-impact hydroelectric projects throughout North America and internationally. Within North America, the proposed developments have generally been limited to smaller run-of-river developments or the addition of low-head powerplants to existing in-river structures. Of particular interest have been the hydropower additions adjacent to existing lock and dam structures within the Ohio and Upper Mississippi River Basins. The existing lock and dam facilities are maintained and operated by the U.S. Army Corps of Engineers and were developed to provide safe and efficient navigation along the rivers for commercial transport of goods. With the addition of a hydropower project, the developer is required to demonstrate that there will be no adverse impacts on navigation and flood levels within the vicinity of the project.This paper will consolidate and discuss the results of nine physical model studies that have been conducted for hydropower additions adjacent to existing lock and dam projects. The primary objective for each of the studies was to evaluate and resolve any impacts on navigation that the proposed development might impose. Secondary objectives have included verifying that the project would not adversely impact flood levels, scour and erosion or environmental habitats in the vicinity of the project. In addition, the project designers have utilized the models to refine the alignment and geometry of the powerhouse approach channel to minimize head losses while providing uniform flow distribution entering the powerhouse intake. In each case, the physical modeling was instrumental in optimizing a project layout that minimized the impacts on river navigation while providing approach and tailrace flow conditions compatible with efficient power generation. The experience gained and the “lessons learned” on the various projects are summarized and discussed, and design recommendations are developed that can be applied to future projects
When talking about sediment issues at hydropower plants or other hydro facilities operators usually face millions of dollars removing or even reducing their problems. Only when economic and/or ecologic pressure starts to force action companies usually drag the sediment or try to flush it out by the dam’s main valve. A prominent example is the great rinse of the Colorado River in 2008 which is going to be repeated at least every two years, probably more frequently. Here each flush comes with the transport of some hundred thousand tons of sediment, but unfortunately also with the loss of some million cubic meters of water and therefore some million dollars in power generation revenues. Dragging the sediment comes with the shutdown of a concerned facility for several months causing the same or even bigger economical effect.A hydro storage power plant in Germany almost inoperable due to sedimentation turned out to be the start for a complete different approach. A combination of wet dredging, new equipment operation techniques and plant operation allows for low cost and no negative effect on plant performance. Once implemented, three years later the plant and combined reservoir is going to be free from sediment problems permanently. The new technical approach is transferable on almost any range of plants, small to large and run-of-river to pump storage. It also restores river morphology almost back to its natural situation improving often criticized ecological matters. Best of all: It fully suits European Water Framework Directive and U.S. sediment acts at no extra cost.
A simulation model was created to identify dam operations and configurations that provided high survivals for Juvenile salmonids migrating out of the Snake River. Regional fisheries managers sought to identify ways to operate and configure the dams and the fish transportation system (barging) to provide safe passage conditions and survival rates that met or exceeded criteria set forth in the Biological Opinion. The challenge was to determine whether a candidate operation or construction item provided the expected survival benefits when the operations and configurations of the entire system were considered. The expected influence of candidate operations and configurations was simulated to screen many millions of combinations and identify the subset that met minimum criteria. Acceptable combinations exhibited a range of survival values, construction costs, and power revenues. This approach provided a set of cost effective combinations from which a mix of survival benefits, construction costs, and power revenues could be chosen to meet stewardship goals.