During the September 2, 2021 Market Subcommittee (MSC) meeting, MISO reviewed Order 2222 framework progress and new recommendations. MISO is requesting Stakeholder feedback on the following recommendations:
Please provide feedback by September 15.
TO: MISO MARKET SUBCOMMITTEE
FROM: THE ENTERGY OPERATING COMPANIES
SUBJECT: ORDER 2222-MODELING, METER AGGREGATION, DEMAND RESPONSE & TELEMETRY
DATE: SEPTEMBER 15, 2021
The following feedback is offered by the Entergy Operating Companies ("EOCs")[1] in response to the request made during the September 2, 2021 Market Subcommittee meeting concerning FERC Order 2222 policy related to modeling, meter aggregation, demand response and telemetry for Distributed Energy Resources (DERs) and Distributed Energy Resource aggregations (DERa).
1. How will DERa be represented in markets, operations, & planning models?
Overall, the EOCs agree with MISO’s Proposal to represent as an aggregate generator which can have a positive or negative capability. We agree that MISO should maintain the current representation of the Transmission/ Distribution (T/D) interface and create a new DERa market resource model with a single EPNode/ CPNode designation. However, we do have a concern with the proposal to represent the aggregate generator as having a positive or negative capability. The concern is that a heterogenous aggregation has the potential to be both a positive and a negative generator. If the positive/negative determination is made using the net nameplate rating of all resources in the aggregation, there could be times when a net negative generator becomes a positive generator because of changes to the availability mix of the resources during the day. If so, this could conflict with MISO’s current proposal to model resources as either being strictly positive or negative. Because of this, the EOCs think this part of the proposal should be further vetted.
2. What is necessary to track performance of DERs and DER aggregations in settlements?
Of the options presented, we would agree with MISO’s proposal to create a new ARC-like process for a Distributed Energy Resource Aggregator (DERA) to submit individual DER and DER Group meter data, with MISO performing the aggregation to evaluate performance. We would point out, based on our ARC experience, that this could be a very complicated process.
In this process, we think that each type of demand response would need to be kept and rolled up separately. As such, this proposal drives home the need for a data repository and should be included in the initial FERC filing.
The EOCs look forward to MISO’s measurement and verification presentation in October, as we see it as a key component in this data collection and aggregation process.
3. How should demand response in aggregations be represented to accommodate 719/745 settlement?
No Comments at this time.
4. What technologies for telemetry is MISO looking at for market operations?
The EOC’s support MISO’s proposal to continue the use of Inter Control Center Protocol (ICCP) via private Wide Area Network as the preferred technology. However, there may be cases where it would be appropriate for an individual Electric Distribution Company (EDC) to use ICCP via Internet with IPSec VPN protection for a DER that is less than 1 MW in size and that is not regulation qualified.
As provided in previous DERTF feedback, the EOC’s would reiterate that the DERA should be the party responsible for all cost and consequences related to telemetry and failure thereof.
5. How often can aggregators change the makeup of their aggregation; e.g., adding or removing individual distributed energy resources?
As also submitted via DERTF feedback, the EOCs support MISO’s proposal, that an aggregator should be able to update the list of individual Distributed Energy Resources (DERs) in their aggregation on a quarterly basis in conjunction with topology model updates. This quarterly timing strikes an appropriate balance for all involved. This approach would also benefit from aligning with other MISO processes, models, and expectations of other resources.
The EOCs appreciated the opportunity to comment.
[1] The Entergy Operating Companies are Entergy Arkansas, LLC, Entergy Louisiana, LLC, Entergy Mississippi, LLC, Entergy New Orleans, LLC, and Entergy Texas, Inc.
WPPI feedback is as follows on the MISO O2x4 recommendations listed:
(1) Representing DERa as aggregate generators while maintaining current Transmission/Distribution Interface
(2) Collecting DER and DER Group meter data for settlements
(3) Settling Demand Response portions of DERa under existing settlement rules
(4) Aligning updates to aggregation with topology model updates
(5) Utilizing existing ICCP [Inter Control Center Protocol] via WAN [private Wide Area Network] for telemetry
Representing DERa as aggregate generators while maintaining current Transmission /Distribution Interface.
DERAs should be represented in market, operation, and planning models like generators, but with positive, negative or variable capability. DERAs--especially heterogeneous DERs--may sometimes provide net curtailment, and sometimes net injection. Models must be able to handle this variability.
As Voltus and other stakeholders have repeatedly argued in task force and committee meetings, as well as in written comments, modeling should not limit DER aggregations to a single EPNode, but should instead allow aggregation at least up to the CP Node level. Precedent within MISO as well as in other RTOs demonstrates the technical feasibility of higher level aggregation, and Order 2222 requires ISOs to permit aggregation to the highest level that is geographically feasible.
MISO Collecting DER and DER Group meter data for settlements?
Voltus encourages MISO to leverage existing technology and processes as much as possible when gathering meter data and tracking performance of DERs and DER aggregations. Existing ARC data management tools, used to collect meter data and calculate load reduction relative to baselines, could work for DERAs with some slight modifications to accommodate a mix of DERs and DER Groups within a DERa and to accommodate resources that inject.
Voltus is supportive of the concept of DER Groups, and the aggregation of data for such groups. DER Groups will be most relevant for aggregations of many small loads or devices, which may lack interval metering. The existing Direct Load Control (DLC) Consumption Baseline, now available only for DRR 1s that are not interval metered, should be expanded to DERs that similarly lack interval metering but can be represented accurately with statistical sampling methods.
Baselines will be more accurate if performance is calculated first and then aggregated across the various DERs and DER groups in an aggregation, rather than aggregating data and then calculating performance.
MISO Settling Demand Response portions of DERa under existing settlement rules?
Voltus agrees with MISO’s proposed approach; the demand response portion of the meter data reported by the DERA will be settled under existing settlement rules developed for FERC Order 745 compliance.
MISO Aligning updates to aggregations with topology model updates.
No comment
MISO Utilizing existing ICCP via WAN for telemetry.
Voltus maintains that real-time telemetry should only be required for provision of products that provide fast response and require data more granular than five minutes to settle. Telemetry should not be required, for example, for capacity products that are dispatched for full hours.
Voltus has encountered many telemetry technologies across different ISOs/RTOs and has found that DNP and HTTP are more stable and less complex than ICCP. Encrypted connections over the public internet are preferable to private WAN; they provide comparable security benefits at lower cost. Private WANs are difficult to set up, complex to administer, and in our experience can lead to less stability and more downtime as a result.