Key Studies

(In reverse chronological order)

Response to ‘Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems’

(ScienceDirect:  Renewable and Sustainable Energy Reviews. Volume 92, July 2018, Pages 834-847)

Significance:  A recent article ‘Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems’ claims that many studies of 100% renewable electricity systems do not demonstrate sufficient technical feasibility, according to the criteria of the article’s authors (henceforth ‘the authors’). Here we analyse the authors’ methodology and find it problematic. The feasibility criteria chosen by the authors are important, but are also easily addressed at low economic cost, while not affecting the main conclusions of the reviewed studies and certainly not affecting their technical feasibility. A more thorough review reveals that all of the issues have already been addressed in the engineering and modelling literature. Nuclear power, which the authors have evaluated positively elsewhere, faces other, genuine feasibility problems, such as the finiteness of uranium resources and a reliance on unproven technologies in the medium- to long-term. Energy systems based on renewables, on the other hand, are not only feasible, but already economically viable and decreasing in cost every year.
Science, Net-zero emissions energy systems

June 29, 2018

Steven J. Davis, Nathan S. Lewis, Matthew Shaner,  Sonia Aggarwal, Doug Arent, Inês L. Azevedo, Sally M. Benson, Thomas Bradley, Jack Brouwer, Yet-Ming Chiang, Christopher T. M. Clack, Armond Cohen, Stephen Doig, Jae Edmonds, Paul Fennell, Christopher B. Field, Bryan Hannegan, Bri-Mathias Hodge, Martin I. Hoffert, Eric Ingersoll, Paulina Jaramillo, Klaus S. Lackner, Katharine J. Mach, Michael Mastrandrea, Joan Ogden, Per F. Peterson, Daniel L. Sanchez, Daniel Sperling, Joseph Stagner, Jessika E. Trancik, Chi-Jen Yang, Ken Caldeira
Significance:  It is very exciting to finally see a fully, integrated, thoughtful, and inclusive overview of the possibilities for building a zero emissions energy system.  These 32 authors do not review the social or political obstacles, rather they review  all of the existing technologies available to address the broad, interconnected system needs of getting to net zero given constraints of cost and effectiveness of the options, without consideration of the popularity or lack thereof of those options.  We have needed this solid and scientific assessment for too long.  Here, in their own words, is the overview of this paper:  

Net emissions of CO2 by human activities—including not only energy services and industrial production but also land use and agriculture—must approach zero in order to stabilize global mean temperature. Energy services such as light-duty transportation, heating, cooling, and lighting may be relatively straightforward to decarbonize by electrifying and generating electricity from variable renewable energy sources (such as wind and solar) and dispatchable (“on-demand”) nonrenewable sources (including nuclear energy and fossil fuels with carbon capture and storage). However, other energy services essential to modern civilization entail emissions that are likely to be more difficult to fully eliminate. These difficult-to-decarbonize energy services include aviation, long-distance transport, and shipping; production of carbon-intensive structural materials such as steel and cement; and provision of a reliable electricity supply that meets varying demand. Moreover, demand for such services and products is projected to increase substantially over this century. The long-lived infrastructure built today, for better or worse, will shape the future.

Here, we review the special challenges associated with an energy system that does not add any CO2 to the atmosphere (a net-zero emissions energy system). We discuss prominent technological opportunities and barriers for eliminating and/or managing emissions related to the difficult-to-decarbonize services; pitfalls in which near-term actions may make it more difficult or costly to achieve the net-zero emissions goal; and critical areas for research, development, demonstration, and deployment. It may take decades to research, develop, and deploy these new technologies.

Silver Buckshot or Bullet: Is a Future “Energy Mix” Necessary? (Received: 29 November 2017 / Accepted: 17 January 2018 / Published: 24 January 2018)
Barry W. Brook, Tom Blees, Tom M. L. Wigley and Sanghyun Hong, University of Tasmania, Science Council for Global Initiatives, National Center for Atmospheric Research, School of Biological Sciences
Significance: To displace fossil fuels and achieve the global greenhouse-gas emissions reductions required to meet the Paris Agreement on climate change, the prevalent argument is that a mix of different low-carbon energy sources will need to be deployed. Here we seek to challenge that viewpoint. We argue that a completely decarbonized, energy-rich and sustainable future could be achieved with a dominant deployment of next-generation nuclear fission and associated technologies for synthesizing liquid fuels and recycling waste. By contrast, non-dispatchable energy sources like wind and solar energy are arguably superfluous, other than for niche applications, and run the risk of diverting resources away from viable and holistic solutions. For instance, the pairing of variable renewables with natural-gas backup fails to address many of the entrenched problems we seek to solve. Our conclusion is that, given the urgent time frame and massive extent of the energy-replacement challenge, half-measures that distract from or stymie effective policy and infrastructure investment should be avoided.
Nuclear Power Learning and Deployment Rates; Disruption and Global Benefits Forgone
(Received: 15 November 2017 / Accepted: 12 December 2017 / Published: 18 December 2017)
Peter A. Lang
Centre for Applied Macroeconomic Analysis, Crawford School of Public Policy, Australian National University, Canberra, Australian Capital Territory 2601, Australia
Significance:  This paper reviews what the environmental and health costs have been from the disrupted trajectory of the transition from fossil fuels to nuclear power, and finds the benefits forgone as a consequence are substantial. Had the original build out plan been realized, not only would nuclear be 90% cheaper, but the additional nuclear power could have substituted for 69,000–186,000 TWh of coal and gas generation, thereby avoiding up to 9.5 million deaths and 174 Gt CO2 emissions. In 2015 alone, nuclear power could have replaced up to 100% of coal-generated and 76% of gas-generated electricity, thereby avoiding up to 540,000 deaths and 11 Gt CO2. With the right growth policies for nuclear, reductions in deaths and in ongoing emissions could be achieved quickly.

Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems


Significance:  An effective response to climate change demands rapid replacement of fossil carbon energy sources. This must occur concurrently with an ongoing rise in total global energy consumption. While many modelled scenarios have been published claiming to show that a 100% renewable electricity system is achievable, there is no empirical or historical evidence that demonstrates that such systems are in fact feasible. Of the studies published to date, 24 have forecast regional, national or global energy requirements at sufficient detail to be considered potentially credible. We critically review these studies using four novel feasibility criteria for reliable electricity systems needed to meet electricity demand this century. These criteria are: (1) consistency with mainstream energy-demand forecasts; (2) simulating supply to meet demand reliably at hourly, half-hourly, and five-minute timescales, with resilience to extreme climate events; (3) identifying necessary transmission and distribution requirements; and (4) maintaining the provision of essential ancillary services. Evaluated against these objective criteria, none of the 24 studies provides convincing evidence that these basic feasibility criteria can be met. Of a maximum possible unweighted feasibility score of seven, the highest score for any one study was four. Eight of 24 scenarios (33%) provided no form of system simulation. Twelve (50%) relied on unrealistic forecasts of energy demand. While four studies (17%; all regional) articulated transmission requirements, only two scenarios—drawn from the same study—addressed ancillary-service requirements. In addition to feasibility issues, the heavy reliance on exploitation of hydroelectricity and biomass raises concerns regarding environmental sustainability and social justice. Strong empirical evidence of feasibility must be demonstrated for any study that attempts to construct or model a low-carbon energy future based on any combination of low-carbon technology. On the basis of this review, efforts to date seem to have substantially underestimated the challenge and delayed the identification and implementation of effective and comprehensive decarbonization pathways.

Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar
(Approved February 24, 2017, received for review June 26, 2016) 

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

Significance:  Previous analyses have found that the most feasible route to a low-carbon energy future is one that adopts a diverse portfolio of technologies. In contrast, Jacobson et al. (2015) consider whether the future primary energy sources for the United States could be narrowed to almost exclusively wind, solar, and hydroelectric power and suggest that this can be done at “low-cost” in a way that supplies all power with a probability of loss of load “that exceeds electric-utility-industry standards for reliability.” We find that their analysis involves errors, inappropriate methods, and implausible assumptions. Their study does not provide credible evidence for rejecting the conclusions of previous analyses that point to the benefits of considering a broad portfolio of energy system options. A policy prescription that overpromises on the benefits of relying on a narrower portfolio of technologies options could be counterproductive, seriously impeding the move to a cost effective decarbonized energy system. [Emphasis added.]

A roadmap for repowering California for all purposes with wind, water, and sunlight

Received 16 December 2013
Received in revised form
21 June 2014
Accepted 26 June 2014
Available online 22 July 2014
Mark Z. Jacobson, Mark A. Delucchi, Anthony R. Ingraffea, Robert W. Howarth, Guillaume Bazouin, Brett Bridgeland, Karl Burkart, Martin Chang, Navid Chowdhury, Roy Cook, Giulia Escher, Mike Galka, Liyang Han, Christa Heavey, Angelica Hernandez, Daniel F. Jacobson, Dionna S. Jacobson, Brian Miranda, Gavin Novotny, Marie Pellat, Patrick Quach, Andrea Romano, Daniel Stewart, Laura Vogel, Sherry Wang, Hara Wang, Lindsay Willman, Tim Yeskoo
Significance: This study presents a “roadmap” for converting California’s electricity, transportation, heating/cooling, and industry energy infrastructure to one derived entirely from wind, water, and sunlight (WWS) generating electricity and electrolytic hydrogen. A survey of available WWS resources is done, along with a projection of total demand growth, after all sectors are electrified. Then, assuming only renewables are installed from 2020 on, the authors devise a mix of energy installations that they claim could replace fossil fuels, assuming neither cost nor land access is a factor, such that 80-85% of existing energy is converted by 2030, and 100% by 2050. The study assumes a reduction in California’s end-use power demand of about 44% and stabilized energy prices.


More background

A look at the controversy between pro-nuclear and anti-nuclear advocates makes it very clear that there are two very distinct positions about nuclear.  How you personally feel about nuclear probably has more to do with which camp you identify with, than with any actual facts. For many people, their minds were made up during anti-war movements, a formative phase that cemented attitudes about nuclear power merely for its associations with nuclear bombs, much like other prejudices that defy facts.  New facts and data are wildly discounted and anyone who expresses support for nuclear is rejected from the group. This makes it impossible for those within the group who do support nuclear to do so publicly.

The main question dividing climate activists is whether we can solve our climate crisis without nuclear power.  To answer this question, there are many assumptions made about how quickly wind and solar can grow in order to replace the use of fuels like coal, oil and gas.  Even those who accept very optimistic assumptions, unlimited resources and production, etc., still recognize that this transition would take multiple decades, given that solar and wind comprise less than 3% of global energy.  Also, as intermittent sources of energy, they may be able to replace some fossil fuel generation on the margins but will necessarily be reliant upon fossil fuels — primarily natural gas generation — due to their intermittency.  Unfortunately, by virtue of the priority given to renewables on the grid, utilities cannot even use more efficient “combined cycle” natural gas generation, as these cannot provide the fast ramping of the more inefficient “single cycle” generators.  Reliance on single cycle plants nearly eliminate the benefits of renewables. Renewable advocates point to the advent of large commercial storage batteries designed to connect to the grid and store up excess energy to be used at night and during bad weather, however, on top of the inefficiency of solar and wind, the replication of capacity deployed with natural gas, the additional costs of these batteries, take the total costs of deploying renewables to a multiple of the cost of generation from nuclear.

There are good reasons to be concerned about using highly contested assumptions as a rationale for  limiting our menu of options for saving the planet. If we are wrong, we simply won’t get another chance.  Nuclear power is the most powerful form of clean energy, so refusing to use it is akin to refusing to use a fire hose when fighting a forest fire.  Given that it has operated safely in the U.S. for forty-five years, even if it has been enshrouded with controversy for much of this time, the facts are clear that no one has died of nuclear power in this country.  Perhaps because of the decades of protests, those operating nuclear power have focused exclusively on safety and not innovation, so we have not benefited from any major improvements in how nuclear works.  This means that nuclear power is the only technology we have now that is still using 1960s-era designs. Clearly it is time for innovation to have a chance. Our risks as a species from climate are many magnitudes greater than any risks we face from nuclear power.

We have a good idea what the issues are with nuclear power. Now, we have reasons to be optimistic that nuclear power will improve dramatically in the next decade or two, addressing all of the issues.  Advanced nuclear designs are being pursued by teams in many countries so it won’t be that long before these newer designs will soon be replacing the 1960’s era Light Water Reactor (LWR) for domestic energy use.  These exciting advanced designs address the issues with the LWR, and some will also be able to take the stockpiles of old nuclear waste and turn that into valuable fuel, eliminating concern about stored waste.