In 2015, PNAS published a paper by Jacobson et al claiming that all of the US energy requirements could be provided by renewables (wind, hydro and solar) by 2050, and that this could be done at low cost. Jacobson had published similar claims on previous occasions, and his nonsense been promoted by irresponsible unscientific organisations such as “Scientific” American and the “Conversation”.
Jacobson’s nonsense has been widely criticised, not just by climate sceptics but by mainstream climate scientists. This article includes polite but sceptical remarks by Tom Wigley and others about his “seriously flawed” work and “unrealistic assumptions”. There was also a paper by Heard et al published earlier this year that critically reviewed several “100% renewable” papers, saying that “none of the 24 studies provides convincing evidence that these basic feasibility criteria can be met.” That paper was discussed at the Energy Matters blog in April.
Now, a new paper, Clack et al, with no less than 21 authors has been published in PNAS, Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar. On the Jacobson et al paper, they say “We find that their analysis involves errors, inappropriate methods, and implausible assumptions.” Some of the errors appear to be quite blatant arithmetic blunders, such as “This figure (figure 4B from ref. 11) shows hydropower supply rates peaking at nearly 1,300 GW, despite the fact that the proposal calls for less than 150 GW hydropower capacity.” The paper has a long section on Jacobson’s implausible assumptions, regarding the huge amount of energy storage required, the capacity factor assumed, and the vast areas of land that would have to be covered in wind turbines. Jacobson et al were allowed to write a response in PNAS.
The new paper is discussed in an article Scientists Sharply Rebut Influential Renewable Energy Plan in MIT Technology Review. In that article Jacobson is quoted as saying “They’re either nuclear advocates or carbon sequestration advocates or fossil-fuels advocates” (does that sound familiar?), a claim that is demonstrably untrue. The lead author Christopher Clack is the founder of a company called Vibrant Clean Energy, whose website promotes wind turbines and solar panels. Choosing another author at random, Paul Hines, you can see from his tweets that he is an enthusiastic proponent of renewable energy.
Jacobson repeats his false smear here (“PNAS published a paper today by nuclear and fossil fuel supporters.”) And on twitter he accuses them of smearing and pushing an agenda. Self-awareness doesn’t seem to be Jacobson’s strength. Andrew Montford notes that Jacobson seems to be following Mann’s example.