Energy Storage Interconnection Initiative

Transcription

1 Energy Storage Interconnection Initiative Stakeholder Call November 25, 2014

2 Agenda Time Agenda Item Speaker 10:00-10:10 Introduction, Stakeholder Process Tom Cuccia 10:10-10:30 Applying the GIDAP to energy storage projects Tom Flynn / Songzhe Zhu 10:30-10:50 Modifying projects to include storage Debi Le Vine 10:50-11:10 Rate treatment issues Tom Flynn 11:10-11:30 charging deliverability assessment Tom Flynn 11:30-11:35 Next Steps Tom Cuccia Page 2

3 ISO Stakeholder Initiative Process We Are Here Page 3

4 Stakeholder process schedule Step Date Event June 24 Post issue paper & straw proposal Round 1 July 1 Stakeholder web conference July 15 Stakeholder comments due Round 2 August 13 Stakeholder meeting August 20 Stakeholder comments due November 18 Post draft final proposal Round 3 November 25 Stakeholder web conference December 12 Stakeholder comments due Page 4

5 Applying the GIDAP to energy storage projects Page 5

6 General approach Interconnection requests to the ISO grid are governed by the Generator Interconnection and Deliverability Allocation Procedures (GIDAP) approved by FERC in GIDAP can accommodate interconnection of storage projects to the ISO grid that want to be treated as generators. Generator that produces positive energy during discharge mode and negative energy during charge mode (this is consistent with how storage participates in ISO wholesale markets under the NGR model). Must respond to ISO dispatch instructions, including curtailment to manage congestion, during both charge and discharge modes. Page 6

7 Reliability studies Considers both discharge and charge modes. Involves testing reliability impacts under worst-case conditions (which may differ between discharge and charge modes). Discharge mode Studied at maximum instantaneous capability in MWs. Both peak and off-peak periods are studied. Peak = summer peak load (typically 1-in-10 peak load forecast is used). Off-peak = spring weekend daytime peak load (50% to 65% of summer peak load). Page 7

8 Reliability studies (continued) Charge mode Studied at highest steady-state charging level in MWs. Both peak and off-peak periods are studied. Peak = summer peak load (typically 1-in-10 peak load forecast is used). Off-peak = night time minimum load (about 40% of summer peak load). Worst-case scenario may be partial-peak Partial-peak = average load of summer weekday two hours before and after the peak period (75% of summer peak load). Page 8

9 Reliability studies (continued) Study results will provide information regarding potential overload issues under assumed conditions. Will identify NUs needed to mitigate reliability problems that cannot be mitigated via congestion management. Any identified reliability NUs may include system protection schemes (SPS). Unlikely that any such requirements would be identified that are in addition to or beyond those required of discharge mode. Page 9

10 Deliverability studies For system and local RA qualification. Only considers discharge mode. Studied at maximum steady-state discharge output level in MWs sustainable for a four-hour period (consistent with CPUC RA counting rules). Peak period is studied Summer peak load (1-in-5 peak load forecast is used). Study results will provide information regarding potential overload issues under assumed conditions. Will identify NUs necessary for the project to achieve its requested deliverability status. Page 10

11 Modifying projects to include storage Page 11

12 Overview Developers may want to modify their projects to add storage. Two existing processes may be used to accommodate such requests. Material Modification Assessment, or The modification review Circumstances may dictate which process to use Is the project in the interconnection queue? If yes, has it achieved commercial operation? Has the project already been approved for repowering? Page 12

13 Projects in the interconnection queue Pre-COD projects should use the Material Modification Assessment process. Evaluates whether change would have material impact on cost or timing of any other interconnection request. If material, then project must submit a new interconnection request. Post-COD projects should request a modification review. Modification is approved if total capability of the project is equal to or less than its existing capability and the electrical characteristics are substantially unchanged. If not approved, then the project must submit a new interconnection request. Page 13

14 Projects already approved for repowering Whether pre- or post-cod for the repowered project, projects already approved for repowering should request a modification review. Modification is approved if the total capability is equal to or less than existing capability and the electrical characteristics are substantially unchanged. If not approved, then the project must submit a new interconnection request. Page 14

15 Rate treatment issues Page 15

16 Non-generator resources (NGR) model Developed as the initial model for energy storage devices to participate in ISO markets and implemented during NGRs are generation resources with a MWh limitation that can be seamlessly moved within an operation range consisting of positive generation only negative generation only, or positive and negative generation ISO settles the energy dispatches for positive or negative energy (i.e., when discharging or charging) at the locational marginal price (LMP). Page 16

17 Rate treatment for energy storage under the NGR model Energy Settlement price Allocated TAC? Positive gen (discharge mode) Negative gen (charge mode) Subject to measured demand uplifts? LMP No No LMP No No Round-trip efficiency losses (i.e., the charge/discharge cycle efficiency) could be argued are part of charging. Page 17

18 Station power Station power would be any energy actually consumed and not energy that is used to charge. Since NGRs are treated as generators, the rules for settlement of station power are the same as for conventional generators. It may be difficult to distinguish station power consumption from charging unless the two activities are metered separately. A project should consult with its LSE to determine how retail charges may apply to its station power consumption. ISO checks the station requirements at sync as part of the new resource implementation process. Page 18

19 charging deliverability assessment Page 19

20 A charging deliverability assessment is fundamentally different Current deliverability assessment evaluates a generator s ability to discharge under resource shortage conditions at peak load (i.e., under specified conditions). However, there is no specific system condition when energy storage must be able to charge. Presumably a charging deliverability assessment must show that full charging is impossible under any conditions. However, constructing a test to demonstrate that something is not possible under one set of conditions does not prove that it is not possible under any conditions. Page 20

21 Uncertainty about how storage will be operated Storage could operate in a manner that alleviates stress on the grid, not by exacerbating this by operating under worst-case conditions. Storage could increase utilization of transmission infrastructure and reduce the need for additional upgrades, rather than being the cause or driver for additional network upgrades. Conclusion: ISO s current path of testing that there is some reasonable window for charging available remains the most reasonable course at this time. Page 21

22 Next steps Page 22

23 Next steps Please submit comments to no later than 5pm on Friday, December 12. Following this initiative, the ISO will consider which of the clarifications contained in the draft final proposal may be appropriate to reflect in the relevant BPM. Page 23