Comments on Installed Capacity Requirement for FCA 12

Legal Document

Dated: November 28, 2017

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Authored by:

United States of America Before the Federal Energy Regulatory Commission 

ISO New England Inc. |  Docket No. ER18-263-000

Comments of the New England States Committee on Electricity 

Pursuant to the Federal Energy Regulatory Commission’s (“Commission” or “FERC”) November 8, 2017 Combined Notice of Filings #1, the New England States Committee on Electricity (“NESCOE”) hereby files these comments in the above-captioned proceeding.[1]  On November 7, 2017, ISO New England Inc. (“ISO-NE” or “ISO”) filed with the Commission the Installed Capacity Requirement (“ICR”) and related values for the 2021/2022 Capacity Commitment Period (the “ICR Filing”).[2]  The Forward Capacity Auction (“FCA”) scheduled for February 2018 (“FCA 12”) is the corresponding primary auction for the 2021/2022 Capacity Commitment Period.[3]  ISO-NE has applied the same core methodology to calculate the ICR and related values for FCA 12 as it has used in prior FCAs, with an incremental adjustment to the methodology used to account for the contributions of behind-the-meter photovoltaic (“PV”) resources (the “PV Forecast”).[4]  NESCOE supports the ICR Filing.


The ICR is intended “to ensure ISO-NE procures sufficient capacity to meet its reliability requirement.”[5]  The 2021/2022 Capacity Commitment Period will mark the third year in which ISO-NE has reflected behind-the-meter PV in its load forecast, one of the primary inputs into the ICR.[6]  The Commission has found that “the incorporation of [solar PV] resources into the load forecast more accurately defines the state of the system and prevents ISO-NE from over-procuring capacity resources.”[7]  The ICR Filing described how, through updated and more granular data, ISO-NE has improved the PV Forecast methodology by moving from a limited “Reliability Hours” approach to an “hourly profile” approach.[8]  NESCOE supports this incremental improvement to the PV Forecast and supports the ICR Filing in general.

Behind-the-meter PV is being installed at a rapid pace in New England and has had “a growing impact on system loads” in the region.[9]   ISO-NE estimated that only 40 MW of solar PV had been installed in New England as of January 2010.[10]  Just six years later, through 2016, that number had grown to 1,900 MW.[11]  ISO-NE projects almost 3,000 MW of additional solar PV installations in the region over the next decade.[12]

ISO-NE’s enhancement to the PV Forecast is consistent with the Commission’s expectation that, beginning with FCA 10, “ISO-NE would work with its stakeholders to address the incorporation of solar PV forecasts into the ICR calculation[.]”[13]  This work was never intended to be a one-time effort, with incorporation of the PV Forecast into the ICR acting as both a starting and an end point.  Instead, the work in connection with the forecast has been an ongoing, and collaborative, effort.  Since FCA 10, ISO-NE has reflected the PV Forecast in the ICR, but, given the limited data available for FCAs 10 and 11, the forecast considered the contributions of these distributed generation (“DG”) resources only during so-called “Reliability Hours” (those hours between 2:00 p.m. and 6:00 p.m. during the summer months).[14]  This Reliability Hours approach was, therefore, considered to be a placeholder pending ISO-NE’s development, working with states and stakeholders, of “a methodology that more accurately reflects the real contribution of [behind-the-meter] PV to load reduction” across a wider range of hours.[15]  NESCOE appreciates ISO-NE’s continued work to improve the accuracy of the PV Forecast.

Earlier this year, ISO-NE appropriately proposed a change to its PV Forecast methodology “as a result of improved databases of [behind-the-meter] PV production.”[16]  As ISO-NE explained, “[u]sing the latest data from the National Renewable Energy Laboratory’s National Solar Radiation Database and state-of-the-art PV modeling tools, the ISO conducted simulations of PV systems’ performance for many thousands of individual systems located throughout New England with sizes ranging from ‘rooftop’ (<10 kW) to ‘utility scale’ (MW-scale).”[17]  This data informed ISO-NE’s development of the “hourly profile” methodology, calculating the load reduction effects of behind-the-meter PV “in all hours of the day and all months of the year.”[18]

During the stakeholder process, some market participants expressed concerns that the hourly profile approach did not sufficiently account for various factors that could affect the impact of behind-the-meter PV on the ICR calculation and sought to delay the implementation of the new methodology.[19]  Other stakeholders stated that the hourly profile approach “was universally viewed to be an improvement” and should not be delayed.[20]  For the reasons discussed above, NESCOE agrees that ISO-NE acted appropriately in implementing the hourly profile methodology and in rejecting the requested delay.  The methodology is grounded in ISO-NE’s analysis of new and more detailed information about solar PV resources on the system and its use of advanced modeling tools to run thousands of simulations testing system performance.  ISO-NE sufficiently demonstrated that its incremental change to the PV Forecast was not only sound but also necessary to ensure that “the load forecast more accurately defines the state of the system and prevents ISO-NE from over-procuring capacity resources.”[21]

In contrast, a delay would fictionalize the state of the system.  It would accept a false and disproven premise that behind-the-meter PV contributes to the system only during so-called Reliability Hours.  This risks ISO-NE procuring more capacity resources than the system needs, exposing consumers to unnecessary costs.  Consistent with the Commission’s guidance, ISO-NE implemented an initial PV Forecast for FCA 10 and then explored changes that would improve the accuracy of the forecast.  These efforts should not be impeded or delayed.  Instead, to the extent the Commission views any additional guidance as appropriate at this time in connection with the ICR, NESCOE respectfully suggests that it should encourage ISO-NE to work on further refinements to the load forecast to ensure that, as DG technologies are deployed in greater numbers and new data and modeling software become available, contributions from all DG resources are reflected in the ICR.


For the reasons stated herein, NESCOE respectfully requests that the Commission consider the above comments in this proceeding.

Respectfully submitted,

 /s/ Jason R. Marshall
Jason R. Marshall
General Counsel
New England States Committee on Electricity
655 Longmeadow Street
Longmeadow, MA  01106
Tel: (617) 913-0342

Date: November 28, 2017


Document Source Citations

[1]     On November 8, 2017, NESCOE filed a timely motion to intervene in this proceeding by doc-less intervention.

[2]     Capitalized terms not defined in this filing are intended to have the meaning given to such terms in the ISO-NE Transmission, Markets and Services Tariff.

[3]     ICR Filing, Transmittal Letter, at n. 7.

[4]     Id. at 4, 7.

[5]     ISO New England Inc., 155 FERC ¶ 61,145 at P 13 (2016).

[6]     See ICR Filing, Transmittal Letter, at 7-9.

[7]     ISO New England Inc., 154 FERC ¶ 61,008 at P 35 (2016) (“January 2016 Order”).

[8]     ICR Filing at 9.

[9]     ISO-NE, Details on the Use of the Solar Photovoltaic Forecast to Modify the Long-term New England Load Forecast, Planning Advisory Committee, April 19, 2017, at Slides 3 and 11, available at

[10]    See ISO-NE, Solar Power in New England: Concentration and Impact, at

[11]    Id.

[12]    Id.

[13]    January 2016 Order at P 27, citing ISO New England Inc., 150 FERC ¶ 61,003 (2015).

[14]    ICR Filing, Transmittal Letter, at 9; see ISO-NE, 2017 Regional System Plan (“2017 RSP”), at 127.

[15]    ICR Filing at 9.

[16]    2017 RSP at 127; see ICR Filing at 9.

[17]    ICR Filing, Prepared Testimony of Ms. Carissa Sedlacek on Behalf of ISO New England Inc., at 15.

[18]    Id.

[19]    See, e.g., Preliminary Minutes of October 13, 2017 New England Power Pool (NEPOOL) Participants Committee Meeting (“NEPOOL Minutes”), at 3840-3841, available at  The preliminary minutes were approved unanimously as circulated.  Noticed Actions of the NEPOOL Participants Committee, Nov. 3, 2017, available at

[20]    NEPOOL Minutes at 3841.  The NEPOOL Participants Committee voted to support the ICR and related values.  ICR Filing at 19.

[21]    January 2016 Order at P 35.