Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Jesse Cyr makes this connection here…

 

The article titled, “Linking Reclaimed Water with Power Generation: Water Reuse and The Energy-Water Nexus” was published on the Global Water Forum website’s Energy board, July, 22, 2014. The news relates to the WRE domain of hydraulics regarding water resource distribution; it also relates to the domain of hydrology with regards to water conservation and sustainability.

 

The article, written by Dr. Ashlynn S. Stillwell, of the University of Illinois at Urbana-Champaign, is based on a study exploring the feasibility of utilizing reclaimed wastewater effluent to cool thermoelectric power plants throughout Texas. The three main factors contributing to the feasibility of linking these resources are geographic, technologic, and economic feasibility. The geographic feasibility examines the spatial distribution of these resources. For wastewater to be an effective replacement to other sources, a wastewater treatment facility must be in close proximity to the thermoelectric plant. The study found that “rules-of-thumb” were in the 10-25 mile range. The technologic constraints on utilizing effluent focused largely on the type of cooling process employed by power plant, mainly comparing between open and closed loop cooling processes, with a preference for closed loop for this application. Lastly the economic feasibility assessed the cost difference between current cooling water sources and the switch to using effluent. While the article does show one graphic that depicts water stress as represented by the thermoelectric cooling constraint index, Figure 2 below, the article does not describe the real need for this technology nor does it discuss the state of water stress in the region. And while the image uses a gradient to distinguish between areas of high and low stress it doesn’t explain how these

 

This article fits into the WRE broader context by focusing on the water energy nexus, which highlights the close relationship between water and energy resources, and has economic and environmental impacts. This close relationship can be seen when we begin to examine how water is treated and how electrical power is produced. To treat water, whether it be potable water for consumption or wastewater to be discharged, there are various energy inputs needed before the water is treated to an acceptable level. These include pumps, stirrers, aerators, UV lights, etc. Conversely, electrical power generation can utilize large quantities of water to cool production processes. This can be seen in all thermoelectric power generation facilities including methane, coal, nuclear and some solar power plants. These relationships impact economics, and the environment. Altering the source of cooling water can affect costs for both water treatment and electrical generation. Environmental impacts may be seen the watersheds surrounding both the wastewater treatment and power generation plants. If these resources are utilized positive impacts may be seen in the surface waters that were once used for cooling. What exactly these impacts would be were not discussed in this article.

 

In another article titled, “South Africa Coal Projects Collide With Water Scarcity, Financial Turmoil” from circleofblue.org, this connection between water and energy resources is similarly clearly defined. Here, the construction of a very large scale coal power plant has been halted by a lack of water for cooling, among other environmental, societal and economic factors. Both articles, while having a focus on water, also indicate a variety of other influencing factors which further tie these issues to the broader concerns at hand.

 

Images:

Figure 1: Decision-aiding map representing where power plants use of reclaimed water for cooling is feasible, source: Global Water Forum

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Figure 2: Picture Showing Indian Point Nuclear Power Plant, source: flickr

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Article URL:

http://www.globalwaterforum.org/2014/07/22/linking-reclaimed-water-with-power-generation-water-reuse-and-the-energy-water-nexus/

 

References:

Fischer, Tony. “Indian Point Nuclear Power Plant.” Flickr. Yahoo!, 9 Aug. 2008. Web. 12 Apr. 2016. https://www.flickr.com/photos/tonythemisfit/2755502911/

 

Stillwell, Ashlynn S. “Linking Reclaimed Water with Power Generation: Water Reuse and the Energy-water Nexus.” Global Water Forum. UNESCO, 22 July 2014. Web. 06 Apr. 2016. http://www.globalwaterforum.org/2014/07/22/linking-reclaimed-water-with-power-generation-water-reuse-and-the-energy-water-nexus/

 

Schneider, Keith. “South Africa Coal Projects Collide With Water Scarcity, Financial Turmoil.” Circleofblue.org. Circle of Blue, 17 Mar. 2016. Web. 06 Apr. 2016. http://www.circleofblue.org/2016/africa/south-africa-coal-projects-collide-with-water-scarcity-financial-turmoil/

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