Compendium of DEFR Analyses

Roger Caiazza

The organizations responsible for the New York State electricity system transition to net-zero agree that new technologies are necessary to keep the lights on during periods of extended low wind and solar resource availability.  This article references six analyses that describe a new category of generating resources called Dispatchable Emissions-Free Resources (DEFR) needed for a future grid that depends upon wind, solar, and energy storage resources.  

Compendium of DEFR Analyses

This article summarizes six analyses describing the need for DEFR: the New York Scoping Plan’s Integration Analysis, New York Department of Public Service (DPS) Proceeding 15-E-0302 Technical Conference, NYISO Resource Outlook, Richard Ellenbogen, Cornell Biology and Environmental Engineering, and Nuclear New York.  I also include the Jacobson and Howarth work that argues that no new technology is needed.

DEFR is not Required

When the Climate Action Council voted to accept the Scoping Plan draft, council members made statements justifying their positions. The statement of Robert W. Howarth, Ph.D., the David R. Atkinson Professor of Ecology & Environmental Biology at Cornell University argued that no new technologies are needed and was uncritically accepted by some members of the Council. Importantly, the leadership of the Council did not object to the following:

A decade ago, Jacobson, I and others laid out a specific plan for New York (Jacobson et al. 2013). In that peer-reviewed analysis, we demonstrated that our State could rapidly move away from fossil fuels and instead be fueled completely by the power of the wind, the sun, and hydro. We further demonstrated that it could be done completely with technologies available at that time (a decade ago), that it could be cost effective, that it would be hugely beneficial for public health and energy security, and that it would stimulate a large increase in well-paying jobs. I have seen nothing in the past decade that would dissuade me from pushing for the same path forward.

This is the reason I am compiling DEFR analyses because it simply is not consistent with any of the organizations accountable for New York energy policy.  The basis of the no new technology claim is the “Wind, Water, and Solar” work of Professor Mark Jacobson of Stanford.  In my summary of this belief, I showed that Howarth’s argument that no new technology is needed has been refuted in the peer reviewed literature.  In the remainder of this article I describe six other analyses that conclude that DEFR is required.

The Jacobson approach wass described in a widely publicized November 2009 Scientific American article by Mark Jacobson and Mark Delucchi that suggested all electrical generation and ground transportation internationally could be supplied by wind, water and solar resources as early as 2030. However, other contemporary projections were less optimistic, for example two examples disagreed: the 2015 MIT Energy and Climate Outlook has low carbon sources worldwide as only 25% of primary energy by 2050, and renewables only 16% and the International Energy Agency’s two-degree scenario has renewables, including biomass, as less than 50%.

Howarth’s statement cites a specific plan for New York (Jacobson et al. 2013) that he and Jacobson laid out a decade ago.  He says that “In that peer- reviewed analysis, we demonstrated that our State could rapidly move away from fossil fuels and instead be fueled completely by the power of the wind, the sun, and hydro.”   There was a formal rebuttal paper to this analysis by Nathaniel Gilbraith, Paulina Jaramillo, Fan Tong, and Felipe Faria. The rebuttal paper argued that: 

The feasibility analysis performed by Jacobson et al. (2013) is incomplete and scientifically questionable from both the technical and economic perspectives, and it implicitly assumes, without sufficient justification, that social criterion would not produce even larger feasibility barriers.

Jacobson et al. responded to that rebuttal claiming  that “The main limitations are social and political, not technical or economic.”  Given the significant differences between that analysis and the most recent projections by the organizations responsible for keeping the lights on, I agree with the Gilbraith et al. conclusion cited above.  I do not believe that the 2013 WWS analysis includes a defensible feasibility analysis proving that a dispatchable, emissions free resource is not needed during extended periods of low wind and solar resource availability.

Three books include analyses that also refute the Jacobson work.  Meredith Angwin’s 2020 book Shorting the Grid: The Hidden Fragility of Our Electric Grid cites academic work rebutting the Jacobson premise.  Angwin also describes two other books that directly refute it.  Roadmap to Nowhere: The Myth of Powering the Nation With Renewable Energy by Mike Conley and Tim Maloney is available as a free PDF download on the web. Mathijs Beckers, of the Netherlands, wrote The Non-Solutions Project, available as an ebook or paperback.

I conclude that the basis for the influential position that no new technology is needed is not supported by the Jacobson work.  More importantly, the following analyses all conclude new technology is needed.

Integration Analysis

The Final Scoping Plan is the “official” Hochul Administration strategy description of the New York Climate Leadership & Community Protection Act (Climate Act) transition.  The Scoping Plan directly contradicts the statement that technologies available when the Howarth paper was written and today are sufficient for the transition away from fossil fuels.  In particular, the Final Scoping Plan Appendix G, Section I page 49 states:

During a week with persistently low solar and wind generation, additional firm zero-carbon resources, beyond the contributions of existing nuclear, imports, and hydro, are needed to avoid a significant shortfall; Figure 34 demonstrates the system needs during this type of week. During the first day of this week, most of the short-duration battery storage is quickly depleted, and there are still several days in which wind and solar are not sufficient to meet demand. A zero-carbon firm resource becomes essential to maintaining system reliability during such instances. In the modeled pathways, the need for a firm zero-carbon resource is met with hydrogen-based resources; ultimately, this system need could be met by a number of different emerging technologies.

The analysis also recommends technologies for this resource:

Hydrogen effectively provides a form of storage to the system on the order of hundreds of hours. Large quantities of fuel can be produced during the spring and summer and then utilized over the course of the winter provided that there is sufficient fuel storage. In addition to hydrogen-based resources, the analysis also examined the potential to meet reliability needs with a long-duration battery storage solution. In this assessment, the firm zero-carbon capacity, as well as renewable resources needed to produce hydrogen, were removed from the system, and the analysis identified a need for 25 GW of 100-hour battery storage to replace the contributions of 21 GW of a fully dispatchable hydrogen-based resource, along with 14 GW of incremental renewable resources to provide storage charging.40 A 100-hour battery resource can provide firm capacity to meet system needs over several days. However, in contrast to a hydrogen-based resource, if sufficient excess energy is not available to fully recharge the batteries following a challenging stretch, their ability to meet a similar system need in subsequent weeks of the winter is diminished. As a result, a higher amount of 100-hour battery capacity is needed to meet the same level of reliability as hydrogen-based resources.

The analyst for the Integration Analysis reiterated this need at the Zero Emissions by 2040 Technical Conference session Gap Characterization  Kevin Steinberger, Director, Energy and Environmental Economics (E3) stated that their modeling consistently showed the need for a new resource that is firm, dispatchable, and has no emissions that can power the system for days without significant recharge from wind and solar resources. 

NYISO Resource Outlook

In all the resource analyses prepared by the New York Independent System Operator (NYISO) since Climate Act implementation began, the necessity of DEFR has been mentioned.  In the spring of 2024 the Power Trends 2024 report notes:

Renewable energy generation, subject to sudden changes in weather, also provides new challenges to grid operators that must balance supply and demand in real time. These variables highlight the need for new generation technologies that can fill in when weather-dependent resources are unavailable. Such new technologies, collectively referred to as Dispatchable Emission Free Resources (DEFRs), must be dispatchable, emissions free, and able to respond quickly to changing grid conditions. Such technologies do not exist yet on a commercial scale.

The NYISO described this resource in the 2021-2040 System & Resource Outlook:

DEFRs are a classification of emission- free resources that provide the reliability attributes of synchronous generation and can be dispatched to provide both energy and capacity over long durations. DEFRs must be developed and added to the system at scale to reliably serve demand when intermittent generation is unavailable. The lead time necessary for research, development, permitting, and construction of DEFR supply will require action well in advance of 2040 if state policy mandates under the CLCPA are to be achieved.

I described the presentation by Zachary Smith that gave an overview summary presentation of the DEFR issue.  In his first slide (shown below) he gave an overview of the generating resource outlook to make the point that a large amount of new generating resources needs to be developed.  The estimates shown are from the 2021-2040 System & Resource Outlook and represent two plausible load projections.  He noted that there are “a lot of attributes that fossil fuel resources provide today that wind, solar, and energy storage simply cannot provide”.  He also made the point that the DEFR replacements do not have to be a single technology but could be several technologies that in aggregate can replace the fossil generation.

Source: New York State Department of Public Service Zero Emissions by 2040 Technical Conference Agenda

Smith listed the attributes needed by DEFR in his presentation.  In my description of his discussion I offered comments on this list of attributes.

Source: New York State Department of Public Service Zero Emissions by 2040 Technical Conference Agenda

Smith’s presentation lists the attributes of twelve sample technologies in the following slide.  This represents the NYISO opinion of the capability of different technologies to meet the attributes necessary to maintain a reliable system.  In the future grid the insistence that all fossil fired units must be shut down means that numerous technologies that meet some of the necessary attributes will be required.  The added complexity of these technologies does not increase resiliency because wind, solar, battery and demand response are all energy limited.  Ancillary support services will be a major consideration because wind, solar and battery do not provide those services.  Just from this overview, it is clear that affordability and reliability will be challenges.

Attributes of Sample DEFR Technologies

Source: New York State Department of Public Service Zero Emissions by 2040 Technical Conference Agenda

Richard Ellenbogen

I described Richard Ellenbogen’s comments as part of the record for the Department of Public Service Proceeding 15-E-0302 related to the net -zero mandate of the Climate Leadership and Community Protection Act (CLCPA). His comments discuss “a viable, affordable, and rapidly executable Plan B to assist NY State in reducing its carbon footprint using technologies that actually exist at scale, unlike the technologies proposed by the CLCPA which only exist at scale in the fantasies of its proponents.”

Ellenbogen lays out reasons that things have changed as the Climate Act is implemented that could affect the schedule and viability of the Scoping Plan list of control strategies.  He concludes that an alternative that does not go to zero provides a better solution. He argues that Interim Combined Cycle Natural Gas Generation phasing to nuclear over time is a far more cost effective and secure way to power the state than what the CLCPA is mandating. Recovering the Combined Cycle emissions in greenhouses will mitigate the negative effect of the carbon emissions. That will also provide energy security that renewables can’t, while simultaneously providing food security as climate change makes food production more challenging.

Cornell Biology and Environmental Engineering

In a post describing the Zero Emissions by 2040 Technical Conference session Gap Characterization  I summarized work by Prof. C. Lindsay Anderson, Chair of Department of Biological and Environmental Engineering Cornell.  Professor Anderson described an analysis her group did using a model they developed.  They made projections for expected loads and potential resources then used 22 years of hourly historical data to model the system.  Without considering cost constraints they assessed system vulnerabilities to evaluate periods where there was insufficient generation to meet projected loads.  Even with optimistic projections they found there will be periods during the coldest and hottest periods where there will be insufficient generation from wind, solar, and energy storage resources.  That gap must be filled with DEFR.

Nuclear New York

I described the independent analysis of the future grid found that New York State has seriously underestimated the need for DEFR. The Filling the Gap in New York’s Decarbonization Plan: A New View of the Electric Grid report was authored by Leonard Rodberg, PhD, Research Director, Nuclear New York, Inc.; Consultant, Energy Policy; Reiner Kuhr, Founder, Center for Academic Collaborative Initiatives (CAIC); and Ahmad Nofal, Co-founder, CAIC. 

The report describes the results of a new modeling tool that allows an hour-by-hour analysis of electric system behavior.  This approach enabled the authors to see details of the hourly operation of each energy source, features not disclosed by existing models.  In my opinion, the CAIC analysis treats DEFR differently than the Integration Analysis does.  I believe that when the Integration Analysis determines which resources should be applied to meet load for each hour, they use DEFR as a last resort.  On the other hand, CAIC uses DEFR much more frequently.  That could be due to a difference in the hourly projections of wind, solar, energy storage, and load for the two models or presumptions in the models.

They found that:

Our hour-by-hour analysis shows that the firm dispatchable source has to run two-thirds of the year. The total load has increased from today. The summer peak has been replaced by a much higher winter peak. That greater demand is met by the extended operation of the DEFR which runs during most evenings in the cooler portion of the year. In fact, we find a capacity factor — the fraction of potential output actually used –of 14.4%.

The report concludes:

We have shown, with a modeling tool capable of performing an hour-by-hour analysis, that dispatchable emission-free resources are essential to meeting the goal of a reliable, zero-emission grid.  Further, this clean dispatchable source must be able to run a large portion of the year. The only such source likely to be available within the next several decades is nuclear power.

Conclusion

There is extensive evidence that a new category of generating resources is necessary for a future grid that depends upon wind, solar, and energy storage resources. Most analysts of the future New York electric system agree that DEFR is necessary to keep the lights on during periods of extended low wind and solar resource availability.   At this point the only questions should be how much, what technologies can be used, and whether any technologies can provide the necessary services affordably.  Arguments that DEFR is not needed are questionable at best.  I would appreciate references to other studies that argue that this resource is needed.

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Roger Caiazza blogs on New York energy and environmental issues at Pragmatic Environmentalist of New York.  This represents his opinion and not the opinion of any of his previous employers or any other company with which he has been associated.