The Gordian Knot Of Grid Resilience – Part 1

April 3, 2018, 7:03PMANS Nuclear CafeSherrell R. Greene

FirstEnergy's recent announcement of its intent to shutter four commercial power reactors at its Perry, Davis-Besse, and Beaver Valley sites is just the latest development in an escalating dialogue about electric Grid resilience and nuclear power's role in enabling and maintaining modern resilient societies and the resilient electricity supply systems upon which they depend. (Within this post, my definition of "Grid" is "the integrated system of U.S. generation, transmission, and distribution assets required to produce and deliver electricity to the end consumer".)

The topic of Grid resilience has attracted increasing attention since the early 2000s, with a variety of federal and private sector studies drawing attention to the vulnerability of the electric Grid, and the Grid's role as the enabler of virtually all other Critical Infrastructure functions.  The pace of the dialog quickened last year with the U.S. National Academies' publication of its report, "Enhancing the Resilience of the Nation's Electricity System."  Among other things, that report highlighted the lack of consensus regarding the basic definition of Grid resilience, and the absence of any practical metrics and predictive methods for assessing the resilience of "real world" Grid systems.

When it comes to predicting Grid resilience, it seems we are in a situation similar to that of the stock market - while a hundred talking heads can give us as many reasons why the market moved as it did just ten minutes after the change occurred, no one could tell us anything with confidence about the market's behavior ten minutes in advance of the movement. To the extent they exist at all, Grid resilience metrics today focus on forensic parameters that are almost impossible to predict, and can only be measured after a Grid disruption occurs. The prediction of Grid resilience for actual systems remains a Grand Challenge. What we need first is a practical working definition of Grid resilience.  Next, a set of Grid resilience metrics that can be employed before an event occurs to predict the resilience of the Grid in advance of an actualized hazard or threat. Then, and only then, can major progress be made toward development of simulation tools and methods to predictively quantify those resilience metrics for real Grid systems.

The dialog about Grid resilience and nuclear power stepped up another notch last September when Secretary of Energy Perry directed the Federal Energy Regulatory Commission (FERC) to execute a rulemaking process to establish electricity market rate structures to compensate "fuel secure" power plants (coal and nuclear) for the particular value they lend to Grid resilience.  FERC's response was, as we know, to decline to execute Secretary Perry's order. Rather, FERC ultimately chose to institute a new rulemaking process (FERC AD18-07) to examine Grid resilience in a "broader context."  The three goals of FERC's action (to quote the order) are: "(1) to develop a common understanding among the Commission, industry, and others of what resilience of the bulk power system means and requires; (2) to understand how each RTO and ISO assesses resilience in its geographical footprint; and (3) to use this information to evaluate whether additional Commission action regarding resilience is appropriate at this time."

Now, what about that Gordian Knot analogy? What are some of the most relevant Grid resilience issues for the nuclear power community to ponder? We'll start there in Part 2 of this post. In the mean time, you can see my (much deeper) dive into those issues in my (Open Access) article the April 2018 issue of the American Nuclear Society's journal, Nuclear Technology.

See you in Part 2!


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