environmental impacts

Mitigation Measures Against Hydropeaking Effects

Source: 
SINTEF Energy Research
Year: 
2011
Abstract: 

Hydropeaking consists of variations in discharge and water level due to releases of water retained in storage basin to generate electricity according to the market demand. These unnatural flow fluctuations create frequent and rapid variations in terms of flow magnitude, flow velocity, water depth, water temperature, wetted area and sediment transport which also can affect channel morphology. Such changes may lead to degradation of physical conditions and habitats in local ecosystems which directly affect biological communities in rivers. Mitigation measures can enhance the ecological state of rivers and lakes altered by hydropeaking. They are classified into 3 different types: Operational measures place constraints on the hydropower plant regime itself, fixing threshold values for amount of water released; construction measures involves construction of hydraulic structures like retention basins; and in-stream measures are renovation or maintenance works carried out inside the river. Mitigation measures are site-specific and thus local investigations must be carried out to ensure successful implementation of measures. In addition, long-term monitoring and systematic evaluation should be conducted during and after the completion of rehabilitation projects to assess the benefits of measures on local ecosystems. The literature review gathers examples of abatement measures implemented in several countries to mitigate negative impacts of hydropeaking. Examples are classified in a table and sorted by the aim of the measures.

 

Author(s): 

Julie Charmasson and Peggy Zinke

Category: 

Development of small versus large hydropower in Norway comparison of environmental impacts

Source: 
Science Direct
Year: 
2011
Abstract: 

This study has compared the accumulated environmental impacts from 27 small-scale hydropower plants with 3 large hydropower projects. The results show a slight tendency that large hydropower has a lower degree of impacts than many small-scale projects, but lack of precision in the data and weak methodological foundation introduces uncertainty in the results. Taking into account other benefits such as the provision of regulated power, it is reasonable to assume that a few large hydropower projects will produce electricity to a lower environmental cost compared to many small projects, which should be considered when realizing renewable energy policy objectives.

 

Author(s): 

 Tor Haakon Bakken, Håkon Sundt, Audun Ruud & Atle Harby

Potential Impacts of Hydrokinetic and Wave Energy Conversion Technologies on Aquatic Environments

Source: 
Fisheries
Volume: 
32 (4)
Year: 
2007
Abstract: 

A new generation of hydropower technologies, the kinetic hydro and wave energy conversion devices, offers the possibility of generating electricity from the movements of water, without the need for dams and diversions. The Energy Policy Act of 2005 encouraged the development of these sources of renewable energy in the United States, and there is growing interest in deploying them globally. The technologies that would extract electricity from free-flowing streams, estuaries, and oceans have not been widely tested. Consequently, the U.S. Department of Energy convened a workshop to (1) identify the varieties of hydrokinetic energy and wave energy conversion devices and their stages of development, (2) identify where these technologies can best operate, (3) identify the potential environmental issues associated with these technologies and possible mitigation measures, and (4) develop a list of research needs and/or practical solutions to address unresolved environmental issues. We review the results of that workshop, focusing on potential effects on freshwater, estuarine, and marine ecosystems, and we describe recent national and international developments. 

Author(s): 

Glenn Cada; Ahlgrimm, James; Bahleda, Michael; Bigford Tom; Stavrakas, Stefanie Damiani; Hall, Douglas; Moursund, Russell; Sale, Michael

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