What is the potential for producing electricity on the Mississippi River?
That is the question that will be discussed Tuesday in a daylong conference at Western Illinois University Quad-Cities, Moline, co-hosted by River Action Inc., Davenport and Western.
The Mississippi River certainly contains enough water to produce electricity; the drawback is that there is not much fall in elevation, according to a paper prepared by Western Illinois professor Roger Viadero and two graduate students in advance of the workshop.
The two exceptions are at Lock and Dam 19 at Keokuk, Iowa, where there is a commercial-scale hydropower facility, and at Lock and Dam 2 in Hastings, Minnesota, where there is a smaller one.
Any new electricity-generating structure — either a retrofit of an existing dam or the building of a new facility — would be a "low-head" facility, where the fall of the water is less than 30 feet, Viadero's paper states. These low-head systems have correspondingly low electric generating capacities.
In low-head systems, water is collected at an elevated upstream location and is conveyed via gravity through a pipe to a turbine that is situated at a lower elevation. Prior to discharge into the turbine chamber, the velocity of water is typically increased by reducing the cross-sectional area of the pipe to create one or more "nozzles," the paper states.
These systems use a small fraction of total river flow and generally don't require significant infrastructure changes to existing waterways, according to the paper.
There are many challenges, however. Among them, according to the paper:
• The lengthy licensing process.
• Coordination among levels of government, regulators and private industry.
• Costs and financing. "The upfront costs associated with the licensing and/or the license exemption processes can be prohibitive for investors," the paper states.
Topics at the workshop will include the history and future of hydropower, the latest technology in turbines, the history and future of hydroelectricity at the Rock Island Arsenal and Lock and Dam 15, environmental designs for low-head waterways, "who foots the bill" and regulations.
The conference is designed to bring together developers, dam owners, energy utilities, clean energy and environmental groups, engineers, public works professionals and city officials.