Jul 22 2012

The Power of Renewables

Published by under Student blog entries

Not even seven percent of the energy consumed by the United States comes from renewable energy sources Matthew Wald explains in his article “The Power of Renewables” published in Scientific American.  Wind, solar, and biofuel energies barely exist when compared to production by fossil fuels (coal, oil, and natural gas).  Though renewable technologies have been making impressive gains in energy generation, coal-fired power plants are multiplying as well as working more hours.

What makes more serious footholds for renewable energy so difficult is the price.  Though investments in renewable energy increased by 60% from 2006 to 2007, the only way it is affordable for the majority ofAmericais through subsides or mandates.  Wald suggests a carbon emission tax to help aid the evening out of costs.  He says a $10 tax per ton of carbon dioxide emitted would only translate to 1 additional cent per kilowatt-hour generated at a coal-burning plant, but all those pennies would make a tremendous difference in energy production across the nation.

What strikes me interesting in Wald’s entire article though is his slight disregard for hydroelectric power.  He does mention that not including hydroelectric power renewable energy wouldn’t even make up 4.5% of theUS’s consumed energy.  Later, he clumps hydroelectric energy with nuclear, coal, and natural gas as he gives an estimate of the average price (11 cents per kilowatt-hour) of electricity produced from these sources.  I wonder how Wald calculated this price—did he lump the totals together and divide or are the prices for all those energy sources really are equal?  I was only surprised because this makes hydroelectric energy sound less renewable.

Finally, “The Power of Renewables” simply failed to acknowledge coastal energy.  The first sentence starts, “Renewable energy, such as from photovoltaic electricity and ethanol,” as if theUnited Stateshas put all our focus onto capturing energy from the sun, and crops (and wind as it later mentions).  I know theUnited Stateslacks many actual installations (especially those that are commercialized) for coastal energy—offshore wind, OTEC, tidal/current, wave, etc.—but I would’ve hoped Wald gave the ocean some recognition in our future outlook and upcoming important areas.

The one reason why I can forgive this slip-up is because Wald did mention an element which many other scientists/authors ignore—energy storage.  After harnessing the earth’s resources for some renewable energies, we face the problem of intermittence.  The electricity produced by the turbines often can only be useful when traveling a limited distance.  Wald acknowledges the possibility of converting, then using the energy for transportation in batteries or even hydrogen.  These may not be the most effective methods, but I applaud Wald for considering the necessity of conversion as we continue to develop renewable energy.

To learn about some of the devices that store and/or deliver renewable power, check out: http://www.nature.com/scientificamerican/journal/v300/n3/box/scientificamerican0309-56_BX2.html



Wald, Matthew L. The Power of Renewables. Scientific American (March 2009), 300, 56-61. 22 July 2012.

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