Correcting Faulty Math on Renewable Energy

July, 2011
The Great Energy Challenge
Renewable energy:  Scientists, governments, and significant elements of the business community now are in agreement that it is the basis around which we can build a low-carbon, sustainable, global energy economy. And yet, misinformation is being propagated by interests favoring the status quo.

A June 7 op-ed,  The Gas is Greener, by Robert Bryce in The New York Times is a sad example. Using rhetorical arguments and faulty calculations, Bryce argues that technologies such as wind and solar are somehow more environmentally destructive than natural gas and nuclear energy. This opinion is at odds with the findings of the several hundred analysts who developed the Intergovernmental Panel on Climate Change’s Special Report on Renewable Energy Sources released last month. It is also at odds with the community of nations who reviewed and endorsed the report and its finding that 17 to 77 percent of global energy needs could come from renewable energy by 2050.

So, what is the truth? Can we build this new energy economy?
Consider the example of California, where detailed and extensively reviewed assessments have shown that with integration and coordination we can readily meet the mandate that one-third of the state’s electricity come from renewable sources by 2020. In projecting the impact of this mandate, Bryce makes several errors, each substantially increasing his estimate of its difficulty. He first ignores the 18 percent of California electricity that already comes from renewable sources, and then inexplicably bases his calculations on peak historic demand rather than the total annual consumption that is subject to this mandate.

This selective lens allows Bryce, like many nay-sayers, to overestimate new infrastructure requirements by over 400 percent. Moreover, both wind and solar are compatible with many other land uses and neither can be said to spoil the land they sit on in any way analogous to fossil fuel extraction or nuclear waste storage. The most important innovations?  Policy and market access.  The wind and solar industries face enormous market incentives to minimize their environmental impacts and both have impressive track records of ongoing innovation in this area.

Meeting a 33 percent renewable electricity mandate nationwide would require on the order of 800 square miles (2,072 square kilometers) of total area–much of which could be on the tops of buildings or in the case of wind, integrated into existing farmland (as is already the case in many wind farms). This is less than twice the size of Edwards Air force base, and less than one third of the area of forest estimated by the U.S. Environmental Protection Agency (EPA) to have already been destroyed by mountaintop removal coal mining.

Critics of the green energy economy often omit key information from consideration in making arguments about the material requirements of energy technologies as well. Bryce, for example compares the steel used for construction of wind and natural gas turbines, neglecting to mention that a gas turbine is only a very small part of a natural gas facility. More importantly, natural gas has substantial fuel production and waste stream infrastructure and impacts. Studies from the EPA indicate that “fugitive” greenhouse gas emissions  associated with natural gas extraction may be far greater than previously thought, diminishing the advantage it is presumed to have over coal,  the dirtiest fuel in widespread use. In contrast, an operating  wind turbine or solar panel requires no fuel inputs and creates no waste stream.

Those of us who have done the math and thus are convinced that a cleaner, safer, and more durable energy infrastructure is worth pursuing, and can be achieved, know that it will be built on a diverse platform of energy technologies. In all likelihood, this will include the natural gas and nuclear power that Bryce advocates, as well as solar, wind, and other renewable energy sources that he unconvincingly criticizes.

What we need most of all is an honest discussion with clear life-cycle, or ‘cradle to grave’ criteria to evaluate the benefits, drawbacks, and roles of each technology and the policy best suited to achieving our societal goals. The most basic lesson from our national innovation and industrial capacity is that we will achieve that which we plan.  Clean energy exists as an option, if we choose to invest in it and to implement systems solutions.

This post was written with guest bloggers Sam Borgeson, who studies low-carbon energy infrastructure, and Kevin Fingerman, who serves as vice-chair of the Roundtable on Sustainable Biofuels.  Both are doctoral students in the Energy and Resources Group at the University of California, Berkeley.