IPWG: Grid-Forming Battery Energy Storage System Performance (PAC-2024-2) (20240502)

NG Renewables appreciates MISOs forward looking approach to grid forming BESS resources and ensuring that there will be a market participation model available to facilitate grid-forming BESS and the significant reliability and economic benefit it can provide to the MISO Market.  

MISOs staged approach to grid-forming BESS is appropriate given the emerging nature of this technology. NG Renewables generally supports the framework outlined on slide 5 and 7. Beginning with basic capabilities and reserving more advanced capabilities like black start for future integration prevents onerous requirements that would discourage the adoption of grid-forming BESS in MISO. In future presentations, MISO should clarify where these standards will be adopted, whether BPM, tariff, or both, and the timeline for filing if applicable.  

In general, NG Renewables would like to echo the sentiments of other stakeholders and note that grid forming technologies are a significant added cost to storage resources. In order to encourage their adoption, MISO should continue to evaluate how it will reward these resources for the valuable reliability services they provide. It would be helpful for MISO to provide a brief overview of the products and services that a grid-forming BESS resource would be eligible to provide that a standard BESS resource would not. MISO might also consider that the development of grid-forming BESS inverter market participation could be coordinated with the “System Attributes” initiative. 

NG Renewables looks forward to future discussions on this topic.  

AES Clean Energy appreciates the opportunity to provide input on MISO’s proposed Grid-Forming Inverter requirements for battery storage. MISO’s proposed framework that separates capability and performance requirements from test requirements to demonstrate conformity is in line with other approaches to compliance. However, AES will need to evaluate the specifics of each requirement and test before we can provide full support for this approach.

Overall, AES believes there may be a gap in IEEE 2800 requirements in relation to Grid-forming capabilities, and MISO should consider how performance requirements for Grid-forming and Grid-following may converge and diverge and what does this mean for each control mode? Additionally, does MISO intend to apply these requirements to all BESS projects (either PV and BESS or BESS standalone)? If not, how would the requirements differ by configuration? 

On Slide 7, AES request MISO clarify the following questions:

• Does MISO intend to test for primary frequency regulation and/or fast frequency regulation?
• What does MISO mean by oscillation damping? Does this mean damping of the plant response to a frequency event or the system/grid network post a contingency? Both have benefits from grid-forming inverters in AES’ experience operating plants with the technology.
• There are multiple testing scenarios, can MISO clarify the exact testing scenarios and provide a clearer table of these?

On Slide 10-11, AES request MISO respond to the following questions:

• What levels of SCR do you currently have or expect to see on your system?
• What specific SCRs does MISO intend to test?
• What research has MISO done on the legitimacy or feasibility of a 60 degree jump that necessitates the testing of phase jumps at this level? A 60 degree phase jump seems extreme and outside the scope of IEEE 2800. It is AES’s understanding that 25 degrees is the typical phase angle jump.

Other questions:

• Can MISO provide more clarity on the type of control method expected from Grid-forming? Do they mean Droop GFM, VSM GFM, or virtual oscillators GFM? (each of these has its pros and cons with capabilities and performance)
• Will MISO require negative current injection from GFM? And will MISO specify a certain required magnitude?
• What is MISO’s proposed timeline for implementation? AES would encourage MISO to continue their proactive adoption of requirements and only apply these requirements on DPP 2024 projects and beyond.
• Has MISO reviewed its market products, and does requiring GFM for BESS make them eligible for new products? What is MISO doing on the market side to enable BESS to be able to provide all the market products and services that these new GFM requirements could create?

DTE appreciates the opportunity to provide feedback on MISO’s proposed grid forming requirements for battery energy storage systems.  We have the following questions and concerns:

1. DTE agrees with MISO’s recommendation for grid forming capability and performance specifications to define voltage source characteristics
2. DTE would like MISO to provide detail and examples of each performance criteria that provide guidance on how inverters should be configured to provide frequency and voltage regulation as well as maintaining synchronism.

We look forward to hearing more from MISO on this topic

MISO presented recommendations for conceptual requirements on battery energy storage (BESS) grid forming controls (GFM) at the May 2 IPWG.  The MISO Transmission Owners (Owners) agree with establishing GFM requirements for BESS and generally support the framework MISO has proposed.  The Owners see value in these capabilities and support the implementation of GFM requirements for BESS as soon as practical.

Re:  Orsted Onshore North America (Orsted) Feedback on May 2 , 2024 Presentation on Grid -Forming Battery Energy Storge System Performance

Please accept the following comments in response to MISO’s May 2, 2024, presentation Grid Forming Battery Energy Storage System (BESS) Performance.  Orsted is a leader in renewable energy and, either directly or through its affiliates, develops, constructs, owns, and operates offshore and onshore wind resources, solar farms, battery storage and offshore transmission facilities.  In MISO, Orsted has 424 MW of wind generation across two wind farms in operation and another 3GW of wind, solar, and storage in various stages of MISO interconnection queue.  Given this commitment to participating in MISO, Orsted is directly impacted by any performance requirements imposed on BESS.   

MISO is proposing conceptual grid forming (GFM) requirements for BESS.  This includes proposing a framework that separate capability and performance requirements from test requirements to demonstrate conformity and GFM capability and performance specifications to define voltage source characteristics.  In developing requirements for BESS, MISO should ensure that they are consistent with existing requirements and technology. 

First, MISO needs to address the discrepancies between the IEEE 2800 requirements for all Inverter Based Resources (IBR) and the proposed GFM BESS requirements.  It is important to note at the time IEEE 2800std was drafted when the GFM technology was in its infancy and meeting some of the 2800std clauses may not be  practically feasible.  Prior to developing new requirements, MISO should resolve any discrepancy between the IEEE 2800 standards,  plant performance capability and the GFM BESS OEM (multiple vendors) performance capability.  Please refer to the General limitations clause 1.4 of the IEEE 2800 standard for detailed explanation.

Second, in the presentation MISO refers to requirements used by the National Grid electricity system operator (NGESO) in the United Kingdom (UK) and by the Australian National Electricity Market (AEMO) as possible tests to supplement verification of GFM controls active and reactive current responses.  These examples may not be reflective of what MISO is trying to achieve s they are voluntary not mandated requirements.  In addition, in both  examples, the requirements for GFM inverter technology is resource neutral (could apply to o solar, wind or BESS).  Having generic GFM, rather than resource specific, requirements, that are voluntary, could drive the market to mature different IBR technologies to meet the requirements furthering efficiencies and technology.

In the UK, it is a best practice and not a mandated requirement that is enforced by the ESO.  Similarly, AEMO has voluntary specification for GFM inverters.  Before creating enforceable technology requirements, MISO should better understand the capabilities and limitations of the technology.  For example, while  NERC’s loss of last synchronous machine simulation broadly tests grid forming performance and current responses, it is unclear how multiple GFM BESS technologies within the same vicinity will impact system stability.  To address these concerns and other possible impacts on the system, MISO should not mandate GFM BESS but rather encourage adoption of new technology through market mechanisms, following the initial adoption approaches by NGESO and the AEMO.

Respectfully Submitted, 

Lopa Parikh, lpari@orsted.com

TO: MISO

FROM: THE ENTERGY OPERATING COMPANIES

SUBJECT: IPWG: GRID-FORMING BATTERY ENERGY STORAGE SYSTEM PERFORMANCE 

DATE: MAY 22, 2024 

The Entergy Operating Companies ("EOCs")^[1] appreciate the opportunity to provide feedback to MISO on Grid-Forming Battery Energy Storage System (BESS) Performance requirements proposed by MISO during the May 2, 2024, Interconnection Process Working Group (IPWG). Entergy is supportive of MISO’s consideration of incorporating grid forming technology requirements for future interconnection requests and offers the following questions to MISO.

Questions

Does MISO intend to apply the grid forming technology requirements to stand-alone BESS only or also to battery facilities that are part of a hybrid project?

Is MISO aware of any existing large-scale transmission-connected BESS with grid forming technology in operation today in the United States mainland? What has been the operational history of these resources?

When aligning with the MISO IEEE 2800 voltage regulation requirements, will MISO require grid-forming BESS facilities to not only have the capabilities that grid forming technology offers but also be required to utilize such features?

[1] The Entergy Operating Companies are Entergy Arkansas, LLC, Entergy Louisiana, LLC, Entergy Mississippi, LLC, Entergy New Orleans, LLC, and Entergy Texas, Inc.

NEER Response to MISO Feedback Request on Grid-Forming Battery Energy Storage System Performance
Due: May 22, 2024

NextEra appreciates the opportunity to provide support for MISO’s Grid-Forming (GFM) Battery Energy Storage System Performance framework, capability requirements, and test simulation requirements. NextEra generally supports MISO’s work this area and believes this to be an important step forward for battery storage. NextEra urges MISO to ensure that the study and implementation processes do not in any way extend the interconnection timeline.  

NextEra looks forward to future engagement and discussions on this topic.

Clean Grid Alliance Comments on Grid Forming Energy Storage System Performance  (PAC 2024-2)
May 22, 2024

At the May 2, 2024, Interconnection Process Working Group (IPWG) stakeholders were invited to review and submit feedback on:

• GFM BESS requirements framework (slide 5)

• Performance and capability requirements (slides 7) centering on defining voltage source characteristics
  
  
• Four test simulation requirements (slide 10-11), including and proposed additions or removals of testing requirements

https://cdn.misoenergy.org/20240502%20IPWG%20Item%2004b%20GFM%20BESS%20Performance%20(PAC-2024-2)632699.pdf

Clean Grid Alliance appreciates the opportunity to provide feedback and generally supports MISO’s efforts. However it is essential that MISO work with stakeholders to develop compensation principles in tandem for grid forming inverters, that are fair and do not disincentivize energy storage on its system. Unfortunately, MISO has suffered from numerous policies that have artificially prevented energy storage from interconnecting to its system[1] resulting in the lost opportunity for GWs of storage that would have otherwise been connected as of today, in the absence of such policy barriers.

To prevent layering an additional financial barrier that further prevents energy storage from interconnecting on its system, MISO can work with stakeholders to develop compensation principles for grid forming inverters, and offer incentives to all inverter-based equipment, without creating mandates. This is a superior and more practical approach.

• A new non-discriminatory market product in tandem with the proposed technical specifications would be ideal
• Additionally, there is precedent for compensating resources for services that NERC recognizes to be useful. NERC has published a whitepaper acknowledging the value of grid-forming inverters, while Schedule 45 allows for Cost Recovery of NERC Recommendations or Essential Actions for Transmission Owners, who can also recover these costs through Attachment O
• MISO should work with stakeholders to develop a fixed fee payment with a performance score. Payments would be higher in locations with more need for grid formation service, as defined by MISO’s MTEP study process. Developers would be incentivized to build projects and provide grid formation at the nodes where the grid most needs this service

Finally, while Clean Grid Alliance supports an incentive approach over a punitive approach, if MISO’s seeks to implement a punitive approach/requirement, we would ask clarification that projects already entered into the MISO generator interconnection queue (having specified or ordered equipment), will be “grandfathered” and exempt from any new requirements enacted after queue entry.  

[1] Delayed implementation of Order 841 (including FERC denied request to delay to 2025), dispatching storage injection in interconnection studies contrary to its application/use leading to unnecessary upgrades, particularly in areas where storage could have addressed congestion (corrected Jan 2023), issues due to modeling of storage charging in interconnection studies contrary to how other loads are modeled, resulting in unnecessary upgrades/limitations on charging (current issue)