Professor Lonnie Gamble | EnergyGrinnell / Writing Assignment

Article Review

Ending a dam nuisance: A new generation of free-standing turbines will liberate hydroelectricity from its dependence on dams

I will be reporting on �Ending a dammed nuisance: A new generation of free-standing turbines will liberate hydroelectricity from its dependence on dams�, an article from the Economist.com, posted February 19th, 2008. The premise of this article is that although hydroelectric energy has been considered a productive, forward-looking renewable energy source, its reliance on damming up rivers has cause substantial negative side effects for the local and global environmental welfare as well as that of local communities, forced to accommodate the artificial lakes these dams require. This article presents innovative technological design advances that do not rely on damming.

As a result of being quite concise, this article begins with the assertion that hydropower is not always welcomed today. This assertion glosses over the benefits that originally made hydropower so palatable and skips directly to problems with it in order to set up the rest of the article�s argument. To quickly review, hydropower is one of the most widely embraced renewable energy resources available on a large scale, claiming the title of the �largest used renewable resource for electricity in Iowa� according to one Iowa Department of Natural Resources website. By transferring the potential energy of elevated water into kinetic energy, hydropower has utilized the natural service of rivers in order to produce electricity. Furthermore, hydropower turbines can reach 80 or even 85% efficiency depending on design.

However, as we have read, efficiency is not by any means the same thing as effectiveness. The article itself, identifies many problematic aspects of currently implemented hydroelectric technology. Dams are labor intensive and costly in acquiring the necessary land, clearing it, construction, and maintenance. In blocking the rivers, dams interfere with animal life cycles, soil nutrient relocation, and cause rapid decay of vegetation producing the greenhouse gas, methane.

This article is not a total endorsement of �free-standing turbines�, however. It emphasizes heavily that these new designs are considerable more vulnerable to damage without a dam to protect them. Along that vein, they are also more difficult to access for repairs, depending on design. Most criticized though, is that they are less efficient that their predecessors. I would posit in response that efficiency is not nearly as important when the source of the energy isn�t used up and thus practically infinitely renewable.

The most ostensible advantage of free-standing turbines is the absence of a dam. The innovative designs of these turbines allows them to achieve sufficient head to produce energy without building up significant water pressure or, in some cases, even building an enclosure. The absences of a large scale enclosure like a dam removes the majority of detriments listed above; there would be no flooding, no plant decay, no housing relocation, no significant land re-management � just a free-standing turbine at the bottom of a moving body of water, even an ocean. The different design concepts also vary in their methods of addressing maintenance issues, from placing the electric generator above water to a small external housing that requires no external lubrication. Again, I would emphasize that while this article cites 25- 30% efficiency, when you can passively collect energy from a ready self-renewing natural resource with limited maintenance, efficiency becomes less important that patience and dedication.

Given this glowing praise, there are a few problems with these designs that remain at the end of the day. For me the most fundamental of these is that, when it comes down to it, instead of trying to assimilating our technology into natural services as environmental leaders such as McDonough, Lovins and Orr have suggested, we are still simply trying to utilize those resources without putting anything back out. I�m not sure what I want out of this design in this regard, but the philosophy intrinsic in it irks me lightly. Furthermore, in the forms described in this article, the designs for these free-standing turbines would need to be adapted heavily depending on the environment to which it was applied. For example the design mentioned above that requires no lubrication and infrequent maintenance would be vastly better suited for oceanic use than that which requires an above water generator. Additionally, in river usage these turbines still present the possibility of disrupting aquatic ecosystems and animal habitats, if in more subtle ways.

On the whole this article gives a generally balanced portrayal of this extremely pertinent technology, focusing more on reporting the characteristics of it and the reasons for its creation than making any judgment on its chances of success or usefulness. Nonetheless, it does lack several significant nuances that highlighted for me the application of the theories and technical information we have studied in this course.