Determination of optimum minimum flow from a dam by using energy analysis

• Published in: Environmental management (New York) Vol. 8; no. 4; pp. 345 - 352
• Main Authors: WILLIAMS, J. B, MCKELLAR, H. N. JR
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 01-07-1984
• Subjects: Applied sciences; Buildings. Public works; Dams and subsidiary installations; Exact sciences and technology; Hydraulic constructions; Energy analysis; Dam; Hydroelectric power plant; Restoration; Flow(fluid); Optimization
• ISSN: 0364-152X; 1432-1009
• DOI: 10.1007/BF01868033

On-off cycling of hydroelectric dam turbines was practised during low river flow conditions to maximise the turbine efficiency, but on-off water flow downstream of the dam might be environmentally unacceptable. An analysis of a dam on the Quinebaug river, Conn., is presented, where the minimal flow through the dam was calculated by maximising the total energy of the water system. The total energy included both the hydroelectric power generated, and an energy equivalent of the aquatic productivity. The latter was calculated from the total surface area of the river system, at various flow rates, and reported data on the rates of oxygen evolution and photosynthesis. Energy quality factors were used to compare calories of aquatic productivity with calories of electricity. Example analyses showed that for short river reaches the total energy was maximized if the minimal dam flow was zero, but for long reaches, or where there were flood plains, the total energy was maximised at full water flow rate, that is, without the turbines operated at all.