Seven years ago we at the North American Electric Reliability Corporation (NERC) sprang into action to help industry understand inverter-based resource risks following the notorious Blue Cut Fire in California in 2016. Since then, I am proud to say that we have poured our hearts and souls into supporting industry as best we could. Some said we moved too slow; others said we moved too fast. But we tried really hard, and that’s something we’re very proud of.
First, I want to highlight two important documents:
- NERC Inverter-Based Resource Strategy: Our strategy document provides a guiding light and direction to ensure we remain focused on identifying, prioritizing, validating, developing, and implementing risk mitigations in this area.
- IBR Quick Reference Guide: We have a one-stop shop that provides links to all the relevant NERC work in this area such as reports, guidelines, standards activities, webinars, etc.
We often get asked what the most important takeaways and recommendations are from all the NERC work in this area. It’s a hard question, because the answer spans stakeholders ranging from inverter controls experts to regulators to policymakers. Nonetheless, I have tried to compile a set of actionable takeaways for you all to drive meaningful change in your roles in this electricity ecosystem. So, here goes…
- We need a comprehensive ride-through standard across North America.
Riding through normal grid faults is an essential reliability service. NERC PRC-024-2 (and then -3) has not served its original intent of ensuring that resources are there when needed. We need to significantly raise the bar and move past the omnipresent fear that a single-line-to-ground fault could cause a blackout because we lose thousands of MWs of generation unexpectedly. That performance is just not acceptable, especially given the rapid pace of change. NERC submitted a Standard Authorization Request after a dozen or so severe events to drive standards revisions; a Standard Drafting Team is currently working on those revisions. Industry should be leaning in with enthusiastic support from all sides.
- The root of many of these problems is in the interconnection study process.
Why are all these plants tripping unexpectedly? We see that the root of the issue is in the interconnection requirements and interconnection modeling and studies. NERC has strongly advised industry to enhance their interconnection requirements for half a decade now. Studies conducted during the interconnection process have failed to adequately identify potential risks; otherwise, those plants would have already addressed these performance shortfalls. Inadequate, inaccurate, or just flat-out bad models are the root of the problem. We cannot let these modeling and studies’ gaps occur during the interconnection process. We need significantly more attention to the quality of the models submitted and the quality of the studies conducted. FERC Order 2023 marked a “win” in this area as the Federal Energy Regulatory Commission (FERC) adopted the strong recommendations made by NERC; a necessary but not sufficient step to shore up these challenges.
- IBR commissioning practices are introducing hidden failures.
Why are the NERC recommendations not sufficient? Because of the commissioning process. We hear from system operators, transmission service providers, generator owners, developers, and even equipment manufacturers that the commissioning process is not what it used to be “back in the day.” Pressures from all sides are prioritizing speed over reliability. Further, there are handoffs that occur here – ownership (from developer to generator owner) and process (from FERC interconnection agreements and procedures to NERC Reliability Standards). So, in essence, it appears to be the Wild Wild West. We see time and again that what was studied during the interconnection process is not what was configured and installed in the field. This includes models (and studies) that don’t match reality or fail to include important protections and controls that could affect performance, and entities on both sides of the transmission/generation divide that are not following up to correct these issues. This is likely because they’re busy trying to get the next project connected as fast as possible. NERC highlighted these issues in the 2022 Odessa disturbance report, as well as in its latest disturbance report where battery energy storage facilities performed abnormally.
- We need specificity and clarity in the NERC Reliability Standards and in the FERC pro forma interconnection agreements.
We have methodically worked through the NERC risk mitigation framework over the past eight years and continue to do so as effectively and efficiently as we can. These are very hard challenges we’re facing and require significant changes to how we’ve conducted business in the past. But the time for change is now. NERC, in collaboration with industry stakeholders, has driven enhancements to numerous NERC Reliability Standards to keep up with the pace of change; there are 10+ projects focused specifically on addressing inverter-based resource (IBR)-related issues in the NERC Reliability Standards underway right now, with more on the horizon coming through the stakeholder process. This is overwhelming industry, but is something we must all help move forward collectively. If not now, then when? And this is while we’re all tackling extreme weather, security risks, electrification of everything, etc. Quite the time to be in our industry!
- IBR model quality needs a reset; inaccurate models result in inaccurate studies.
If you run a study with a model that is wrong, your study is wrong. If you run a study with a model that is missing important pieces of information, your study won’t identify risks in those areas. And that’s what we’ve observed numerous times, and published multiple reports on. We have widespread modeling issues with the existing fleet. NERC has identified these challenges through our objective and independent assessments, and industry has moved to make corrections where they can. But we really need a reset. When we ask the transmission planners whether they believe their models are accurate and we get “unknown” across the board, that should scare all of us (see Table 3.4 in 2022 Odessa report). When we’re told that the models are accurate and we do cursory reviews and identify blatant modeling errors, that should scare us even more. We need a comprehensive modeling assessment to understand where our hidden risks are due to modeling practices that could fail to identify reliability issues. NERC is initiating work in this area to help drive meaningful change across the industry, in addition to the multiple NERC Reliability Standards projects underway now.
- We have a single point of failure problem in this industry right now.
That single point of failure is the original equipment manufacturers (OEMs). And it has nothing to do with them – they’re great! We recently issued a Level 2 NERC Alert that required solar generator owners to report data about their facility to NERC: reactive capability, protection settings, control modes, etc. What we heard nearly unanimously was that the owners had to go to their OEM for information, which created a bottleneck for a small handful of folks at the OEMs to gather data for hundreds of facilities. Deadlines were extended (a rare occurrence) because the initial response rate was very low. We really need change here, so that basic things like access to data (oscillography data, fault codes, settings, parameters, etc.) is not all inside some black box. Generator owners should understand where and how to gather necessary data when requested.
- Data equals information, information equals knowledge, knowledge equals technology innovation.
This one may sound fluffy but it is overlooked. People these days are saying we’ve had little impact, and I counter with this. Our event analysis process helps us (NERC) gather data and information to do high-quality engineering analysis. Those analyses help us understand more about the inverter-based fleet, and we share information widely across North America and the world. After every event, we sit down with the affected OEMs and specifically ask, “how are you addressing these issues in your fleet?” A ton of changes are made proactively to new product development, and affected owners are asked to make changes at their facilities to correct issues. We also push the OEMs as much as we can to proactively address these issues across their existing fleet; however, multiple OEMs have stated that corrections will only be rolled out when generator owners approach them to implement fixes. This type of behind-the-scenes technical leadership across the ERO Enterprise (NERC and its Regional Entities) is a little-known success story.
- The boom of batteries presents an opportunity, but only if we act now (not later).
We are seeing an exponential growth of battery energy storage systems (BESS) connecting to the bulk power system, with exponential growth projected in the years to come. BESS offer a unique opportunity for us to harness multiple value streams. But I want to focus on the one that gets both all the attention and little attention: grid- forming (GFM) technology. We hear from across the industry that leveraging GFM technology in BESS is a “no-brainer” – yet nearly every BESS being interconnected is not enabling this grid-stabilizing feature. Why? We must break the “chicken and egg” cycle and unlock this societally valuable functionality across the board.
The future grid dominated with IBRs will need as much grid-stabilizing capability as possible. Let’s stop getting bogged down in the “how much” and “by when” and “how do you know” arguments. We lack interconnection-wide electromagnetic transient (EMT) modeling capability. So it’s like driving in a snowstorm with your eyes closed. We must open our eyes, put on the snow chains (GFM tech), and proceed forward – because there’s no turning back. Check out NERC’s recent white paper developed by industry experts that establishes a functional specification and test procedures for GFM in BESS moving forward.
- We have to move past the complaint that electromagnetic transient (EMT) studies are “too hard” or “slow down the process.”
EMT is still in its nascent phase in the transmission planning process. Some entities are starting to really conduct EMT studies more broadly, but mostly we are behind. We all acknowledge that we lack the skills, resources, people, technology, and tools to run the EMT studies needed for future IBR interconnections. Yet we all seemingly agree that it is absolutely necessary for us to be running these studies. The positive sequence tools still serve a purpose, but for IBR interconnection/reliability studies, we need significantly more EMT study work going on. Otherwise we run the risk of missing important risks. In walks Blue Cut Fire holding hands with Odessa #1 and Odessa #2. You’ve heard this story before. But we cannot let “it’s too hard” or “it’s too slow” get in the way of the necessary end vision.
- Those who engage, reap the rewards; those who do not, fall behind.
The last thing I will say is GET ENGAGED. The NERC Inverter-Based Resource Performance Subcommittee (IRPS) and NERC Electromagnetic Transient Task Force (EMTTF) are incredibly impactful and empowering forums for industry to learn, share, and stay up-to-date on the latest industry findings. Both are excellent forums for developers and generator owners to gather useful insights as they work through the interconnection process and during commercial operation. ESIG also has working groups and task forces producing really valuable work. And I know many other industry forums are also driving meaningful content. But what I’ve noticed is that people who really get engaged (ask questions, share thoughts, etc.) are the ones that get the most out of it. Don’t dial in to listen, dial in to learn and connect. Otherwise you’re missing out on all that our incredible engineering community has to offer.
I hope this was useful, informative, and mildly entertaining. If you’re new to this space, hopefully this is a call to action. If you’ve been around since the early days, this all probably resonates strongly and I thank you for being part of this saga.
Director, Engineering and Security Integration
North American Electric Reliability Corporation (NERC)
The views expressed in this post are my own and do not represent those of the North American Electric Reliability Corporation.