June 23, 2017
Economics, Grid, U.S.

Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar

Clack, Christopher; Qvist, Staffan; Apt, Jay; et al.

[Abstract] 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. [Proc Natl Acad Sci U S A 2015;112(49):15060–5 (ref. 11)] 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 short- comings 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.

[Introduction] Wind and solar are variable energy sources, and some way must be found to address the issue of how to provide energy if their immediate output cannot continuously meet instantaneous demand. The main options are to (i) curtail load (i.e., modify or fail to satisfy demand) at times when energy is not available, (ii) deploy very large amounts of energy storage, or (iii) provide supplemental energy sources that can be dispatched when needed. It is not yet clear how much it is possible to curtail loads, especially over long durations, without incurring large economic costs. There are no electric storage systems available today that can affordably and dependably store the vast amounts of energy needed over weeks to reliably satisfy demand using expanded wind and solar power generation alone. These facts have led many US and global energy system analyses (1–10) to recognize the importance of a broad portfolio of electricity generation technologies, including sources that can be dispatched when needed.

[Conclusions] The scenarios of ref. 11 can, at best, be described as a poorly executed exploration of an interesting hypothesis. The study’s numerous shortcomings and errors render it unreliable as a guide about the likely cost, technical reliability, or feasibility of a 100% wind, solar, and hydroelectric power system.

Christopher T. M. Clack, Staffan A. Qvist, Jay Apt, Morgan Bazilian, Adam R. Brandt, Ken Caldeira, Steven J. Davis, Victor Diakov, Mark A. Handschy, Paul D. H. Hines, Paulina Jaramillo, Daniel M. Kammen, Jane C. S. Long, M. Granger Morgan, Adam Reed, Varun Sivaram, James Sweeney, George R. Tynan, David G. Victor, John P. Weyant, and Jay F. Whitacre

Proceedings of the National Academy of Sciences of the United States of America
Published online June 19, 2017 [1]. doi: 10.1073/pnas.1610381114 [2]

Download original document: “Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar [3]

Download Supporting Information Appendix [4] containing the details of this evaluation.

Download Dataset 1 [5] and Dataset 2 [6] containing data and calculations used to produce the figures.


URL to article:  https://www.wind-watch.org/documents/evaluation-of-a-proposal-for-reliable-low-cost-grid-power-with-100-wind-water-and-solar/


URLs in this post:

[1] Published online June 19, 2017: http://www.pnas.org/content/early/2017/06/16/1610381114.full

[2] 10.1073/pnas.1610381114: https://doi.org/10.1073/pnas.1610381114

[3] Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar: https://docs.wind-watch.org/Clack-et-al-PNAS-2017.pdf

[4] Supporting Information Appendix: https://docs.wind-watch.org/Clack-et-al-appendix.pdf

[5] Dataset 1: https://docs.wind-watch.org/Clack-et-al-dataset-1.xls

[6] Dataset 2: https://docs.wind-watch.org/Clack-et-al-dataset-2.xlsx