Real-Time Data Requirements for Incorporating Wind and Solar Resources into Market Rule 1

1. june 10-12, 2019 | westborough, MA Jonathan Lowell jlowell@iso-ne.com | 413-540-4658 Incorporating Wind and Solar Resource Real-Time Data Requirements into Market Rule 1 Solar Data Requirements

2. Solar Data Requirements WMPP ID: 137 Proposed Effective Date: October 2019 For situational awareness and efficient system dispatch, real-time meteorological and forced outage data telemetry from solar resources will be important as grid-connected solar penetration increases ISO is proposing to establish real-time data telemetry requirements for solar resources that are nearly identical to existing wind resource data requirements contained in the ISO-NE standard Large Generator Interconnection Agreement (LGIA) which is contained in Schedule 22 of the Open Access Transmission Tariff Requirements for both solar and wind will now be consolidated in a new location in Market Rule 1 (MR-1) Today’s presentation will focus on: • Discussion of the data and why it is required • Greater clarity on who is affected • Review of proposed tariff changes

3. Real-time data requirements for wind and solar Generator Assets will be included in MR-1 Existing wind data requirements will be deleted from the ISO-NE standard LGIA, clarified, and moved to MR-1 New, very similar data requirements will be established for solar in MR-1 FERC Order 764 (Integration of Variable Energy Resources, issued 6/22/2012) required meteorological and forced outage related data requirements to be included in the tariff The wind and solar data requirements play an important role supporting unit-specific short-term power production forecasts, which are necessary to enable these resources to be dispatched under the Do Not Exceed (DNE) approach • Wind is subject to DNE dispatch today • Solar DNE dispatch is anticipated in the 2021-23 timeframe, but no specific implementation date has yet been established

4. What changes are being proposed? The new solar data requirements will be located in MR-1 • Most new solar resources are voluntarily adhering to the proposed solar data requirements Wind data requirements will be relocated from the LGIA into MR-1 • Moving the requirements into MR-1 ensures that the requirements apply to wind resources that may not be interconnected through the ISO-NE interconnection process • Resources that interconnect through a state interconnection process would not have a standard ISO-NE LGIA • In actual practice, there are no affected existing wind resources that are not already meeting the requirements

5. Related non-tariff changes A new OP14 Appendix H (OP-14H) will be created later this year specifically for solar resources • OP-14H will be separately reviewed by the NEPOOL Reliability Committee • OP-14H will be similar to existing OP14 Appendix F for wind, which contains additional operational practices and recommendations. Examples include: • Ramp rate limitations • Recommended (not required) data collection points

6. Why is real-time data and outage information needed from solar resources? The real-time data facilitates an accurate, resource-specific forecast of power production Benefits of an accurate solar forecast: • Prior to solar DNE implementation, helps to plan the system to minimize the likelihood of the need for manual dispatch of solar resources in congested areas, or during times of minimum generation emergencies • Enables solar DNE dispatch to: • help to maximize the use of low cost renewable energy, • improve congestion management in constrained areas • set appropriate energy price signals for the market • Note that the ISO separately forecasts the impact of distributed solar facilities (e.g., rooftop solar) which is treated as a reduction in the load forecast

7. What are the operational challenges associated with grid-level solar resources? No significant challenges yet, though the ISO anticipates that expected increases in solar penetration will lead to future challenges Potential challenges (very similar to wind): • Fast ramping resources – solar resources will ramp on and off quickly. Understanding the forecasted output of these resources will be critical to ensuring the system is prepared to accommodate the rapid increase and decrease in power output • Export constrained areas – understanding of planned power injections will be critical to ensure that operating limits are not exceeded as these resources ramp online • Import constrained areas – understanding of planned reductions in power injections will be critical to ensure that operating limits are not exceeded as these resources ramp offline • Compliance with NERC balancing standards – fast ramping can cause difficulties in maintaining correct relationship between the supply-demand balance and system frequency • Overall system capacity – an accurate understanding of the expected output from intermittent solar resources helps ensure system capacity needs can be met without over- or under-commitment • 2nd contingency coverage in local reserve zones – important to understand expected output of these intermittent solar resources so the reliability needs of the local area can be met

8. Who will be affected? Most new solar resources are already voluntarily adhering to the proposed solar data requirements The proposed tariff changes mean that “Wind and solar Generator Assets that are not Settlement Only Resources” will need to comply with the data requirements • Generator Asset is a defined term in section I.2.2 of the tariff: “Generator Asset is a device (or a collection of devices) that is capable of injecting real power onto the grid that has been registered as a Generator Asset in accordance with the Asset Registration Process.” • The proposed tariff changes do not affect Settlement Only Resources, Demand Response Assets, or Demand Capacity Resources, such as: • An end-use customer with a solar facility located behind its the Retail Delivery Point (aka “behind-the-meter”) that participates in the market as a Settlement Only Resource • An end-use customer participating in the market as a Demand Response Asset that has a solar facility located behind its Retail Delivery Point • A directly-metered solar facility that participates in the market as a Demand Capacity Resource, which is located behind the Retail Delivery Point of an end-use customer In general, rooftop solar connected at the distribution level is not going to be registered as a Generator Asset and would therefore not be affected

9. Summary of Solar Data Requirements Meteorological data – at least every 5 minutes: • Wind speed and direction • Temperature and temperature standard deviation • Relative humidity and relative humiditystandard deviation • Atmospheric pressure and atmospheric pressurestandard deviation • Irradiance Forced outage data – at least every 5 minutes: • Real-Time High Operating Limit • Solar High Limit • New defined term, analogous to Wind High Limit Other outage data: • Solar Plant Future Availability • Hourly for the next 48 hours • By 10am each day for the next 48 to 168 hours • New defined term, analogous to Wind Plant Future Availability

10. Terminology change proposed from “photovoltaic” to more general term “solar” • For consistency in terminology within the tariff, an occurrence of “photovoltaic” will be modified to say “solar” • Exception: the use of “photovoltaic” in the audit rules at MR-1 III.1.5.1.2(h) is being retained • Note that “solar” includes any resource that uses energy from the sun, including solar thermal facilities • Currently, all existing and anticipated solar resources in New England rely on photovoltaic technology to produce electricity

11. Implications of DNE Dispatch for Solar Resources The tariff language in Section III.13.6.1.6 currently requires that Do Not Exceed (DNE) Dispatchable Generators… “… with a Capacity Supply Obligation must submit offers into the Day-Ahead Energy Market for the full amount of the resource’s expected hourly physical capability as determined by the Market Participant.” Implementation of DNE dispatch for solar resources is anticipated in the 2021-23 timeframe The Day-Ahead offer requirement for DNE dispatchable solar facilities willtake effect beginning June 1, 2023 • This is the start of the Capacity Commitment Period associated with FCA14 (to be conducted in 2020) • Solar developers should consider this Day-Ahead offer requirement when preparing capacity market offers for FCA14

12. Final Note – Order 764 and LGIA Order 764 requires each public utility transmission provider to: “incorporate provisions into the pro forma Large Generator Interconnection Agreement requiring interconnection customers whose generating facilities are variable energy resources to provide meteorological and forced outage data to the public utility transmission provider for the purpose of power production forecasting.” ISO believes moving these requirements into MR-1 will • Achieve FERC’s intention of ensuring data requirements part of the ISO’s FERC-approved tariff • Avoid the need to replicate wind and solar data requirements in both the ISO-NE LGIA and the Small Generator Interconnection Agreements (SGIA) • Will address all of the solar resources for which situational awareness is going to be important • Including those interconnected through a state interconnection process (i.e., not the LGIA or SGIA)

13. Tariff Changes

14. Conclusion • Solar and wind resource data requirements will be centralized in MR-1 • Several new defined terms are added for both wind and solar resources • No change to wind resource requirements (other than tariff location), but extends tariff requirements to smaller facilities not covered by the LGIA • Solar resource requirements will replicate wind resource requirements very closely • Solar resource requirements expected to become effective in October 2019, upon FERC approval

15. Stakeholder Schedule

17. Acronyms Used in this Presentation DNE – Do Not Exceed FCA – Forward Capacity Auction FERC – Federal Energy Regulatory Commission LGIA – Large Generator Interconnection Agreement MR-1 – Market Rule 1 OP14 – ISO New England Operating Procedure No. 14; Technical Requirements for Generators, Demand Resources, Asset Related Demands and Alternative Technology Regulation Resources SGIA – Small Generator Interconnection Agreement