NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, o...

The concept of green hydropower needs an evaluation procedure for the ecological upgrading of hydropower plants based on scientific criteria [1]. For the planning and evaluation of riverrestoration programs, concepts like “ecosystem integrity” or “river health” have been proposed and empirically tested. Computer programs have been developed, which allow the testing of alternative restoration co...

Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reserv...

-This paper presents recent work on the control strategy and algorithm for automatic voltage control (AVC) of hydropower station with multiple units and large capacities. Under the conditions that no dynamic voltage problems are considered, a method intended primarily to control steady state voltage of HV bus by economically regulating the reactive power generation of hydropower station is prop...

Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some rivers reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to preliminarily evaluate remov...

The sediment flux through Himalayan rivers directly impacts water quality and is important for sustaining agriculture as well as maintaining drinking-water and hydropower generation. Despite the recent increase in demand for these resources, little is known about the triggers and sources of extreme sediment flux events, which lower water quality and account for extensive hydropower reservoir fi...

On the basis of the analysis of the basic information of the river basin reservoirs and application of chaotic ant swarm algorithm, the medium-and long-term optimization operation model is established, which regards the maximum annual generation capacity of the cascade hydropower stations as the main purpose. The simulation result shows the algorithm improves the total annual power generation o...

Theoretical hydropower operation rules are derived and discussed for reservoirs in parallel, in series, and single reservoirs for cases where reservoirs typically refill before they empty and for parallel reservoirs when reservoirs are expected to draw down to empty. These hydropower rules offer a simplified economic basis for allocating storage and energy in multireservoir hydropower systems. ...

Hydropeaking operations can severely degrade ecosystems. As variable renewable sources (e.g. wind power) are integrated into a power grid, fluctuations in the generation-demand balance are expected to increase. In this context, compensating technologies, notably hydropower reservoir plants, could operate in a stronger peaking scheme. This issue calls for an integrated modeling of the entire pow...

Large hydropower project (LHP) is now the most important renewable and low-carbon source for electricity generation, carbon footprint calculation is crucial for it. We established an embodied carbon budget accounting system for LHP to calculate its actual carbon footprint. In additional to traditional carbon emission from plant construction, the accounting system included two new items in the c...