Power density, energy density, cost and scale

Review by Jason Hayes, Communications Director, American Coal Coun

With the publication of Power Hungry, Robert Bryce continues in his established tradition of in-depth research and bluntly presented findings. He’s not known around the Internet, or in policy circles, as weak-kneed, or easily swayed. On the policy front, Bryce doesn’t tend to mince words. He is an equal opportunity critic, pointing out the mistakes of concepts and practices on all sides of the political spectrum.

He’s also an experienced researcher, with volumes of background material to back up his unique views. It’s therefore difficult to miss Bryce’s extensive preparation and the sizable references section in Power Hungry. It’s also easy to enjoy his generally even-handed approach, admitting problems, as well as recognizing the positive aspects of energy sources – even those that did not make the cut into his N2N (natural gas to nuclear) energy policy for the future. I was encouraged to see a book that takes a serious look at the costs of renewable energy sources. However, I was disappointed by Bryce’s willingness to overlook or omit basic facts related to coal use and the many technologies available to address coal-related environmental concerns.

Throughout the book, I was pleasantly surprised to find an author who is willing to take energy resources to task where they have real flaws, but who will also rationally assess risks and support their use when the benefits outweigh the costs. Many authors and policy wonks have fallen under the spell of the politically correct, ‘if it’s labeled green, it’s gotta be good’ mindset – they can’t muster the courage to openly admit that all energy resources, even renewables, have environmental, social, and economic costs associated with their use. That’s not Bryce; he lays bare the skeletons in the green energy closet, openly detailing the costs and environmental impacts of moving to a renewables-based energy supply. Amusingly, he even has the chutzpah to unseat the Danes as THE example the world should follow when it comes to the use of renewable energy. He exposes the well kept secret that, despite all their new wind-based electricity production, Danish coal consumption has not decreased over the past three decades.

Throughout the book, Bryce is an outspoken proponent of the continued use of hydrocarbon-based fuels, primarily because those fuels – unlike renewable options, and other so-called green fuels – meet his four-part test of power density, energy density, cost and scale.

Bryce demonstrates how renewable energy sources fail to meet both the power and energy density test. With regard to power density, renewables harness a limited amount of energy per given unit of volume, or mass. Translated into English, they require a lot of space or volume to produce the energy found in much smaller units of fossil fuels. That’s why wind farms and solar installations must be spread across large tracts of land, or why replacing just 10 percent of coal-fueled energy generation in America with wood would more than double overall U.S. wood consumption. With regard to energy density, renewables store far less energy per unit of volume than hydrocarbon-based fuels. His example is the available energy stored in a 5 gallon bucket of dried leaves is far less than that stored in the same bucket, full of gasoline. That comparison remains true if one switches out the leaves for corn ethanol, gasoline for anthracite, etc.