Clack CTM, Qvist SA, Apt J, Bazilian M, Brandt AR, Caldeira K, Davis SJ, Diakov V, Handschy MA, Hines PDH, Jaramillo P, Kammen DM, Long JCS, Morgan MG, Reed A, Sivaram V, Sweeney J, Tynan GR, Victor DG, Weyant JP, and Whitacre JF
A number of analyses, meta-analyses, and assessments, including those performed by the Intergovernmental Panel on Climate Change, the National Oceanic and Atmospheric Administration, the National Renewable Energy Laboratory, and the International Energy Agency, have concluded that deployment of a diverse portfolio of clean energy technologies makes a transition to a low-carbon-emission energy system both more feasible and less costly than other pathways. In contrast, Jacobson et al. [Jacobson MZ, Delucchi MA, Cameron MA, Frew BA (2015) Proc Natl Acad Sci USA 112(49):15060-15065] argue that it is feasible to provide "low-cost solutions to the grid reliability problem with 100% penetration of WWS [wind, water and solar power] across all energy sectors in the continental United States between 2050 and 2055", with only electricity and hydrogen as energy carriers. In this paper, we evaluate that study and find significant shortcomings in the analysis. In particular, we point out that this work used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions. Policy makers should treat with caution any visions of a rapid, reliable, and low-cost transition to entire energy systems that relies almost exclusively on wind, solar, and hydroelectric power., Competing Interests: Conflict of interest statement: The authors declare no conflict of interest, and with the exception of S.A.Q., none received support from sources other than normal salary from their employers for work on the preparation of this paper. With the exception of M.B. and J.C.S.L., all of the authors have recently received outside support for more general research on energy systems and renewable energy. C.T.M.C. received support in the past from NOAA. S.A.Q. was supported for analysis that supported this paper by the Rodel Foundation of Delaware and has received more general faculty funding from Uppsala University. J.A. and M.G.M. have received support from the National Science Foundation (NSF), EPRI, the Doris Duke Charitable Foundation, and members of the Carnegie Mellon Electricity Industry Center. A.R.B. has received support from the California Air Resources Board, the Carnegie Endowment for International Peace, Argonne National Laboratory, Sandia National Laboratory, NREL, Ford Motor Company, and Saudi Aramco. K.C. has received support from the Carnegie Institution for Science endowment and the Fund for Innovative Climate and Energy Research. S.J.D. has received support from the NSF. V.D. has received support from NREL. M.A.H. has received support from the NSF and DOE. P.D.H.H. has received support from the NSF and DOE. P.J. has received support from the NSF, EPA, and NOAA. D.M.K. has received support from the NSF and the Zaffaroni and Karsten Family Foundations. A.R. has received support from the NSF. V.S. has received support from the Sloan Foundation. J.S. has received funding from Jay Precourt, Bloom Energy, EPA, ExxonMobil Corporation, California Energy Commission, and DOE. G.R.T. has received support from DOE and the University of California, San Diego (UC San Diego) Deep Decarbonization Initiative. D.G.V. has received support from EPRI, the UC San Diego Deep Decarbonization Initiative, and the Brookings Institution. J.P.W. has received support from DOE, EPA, and industry affiliates of the Energy Modeling Forum. J.F.W. has received support from the NSF, DOE, DOD, Toyota, and Aquion Energy.