Non-Generator Resources - Regulation Energy Management

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California Independent System Operator

Non-Generator Resources – Regulation Energy Management – Frequently Asked Questions

10/24/2011

1. "NGR can be used to model a LESR or a DDR. If a demand response resource combining with

generation ability can inject power into the grid, the combined resource shall be modeled as a

LESR. In general, a LESR is not limited to a storage resource; any resource that can operate

seamlessly from negative to positive shall register LESR." (p. 9)

a. I do not believe that this is a useful assumption. The issue is that the LESR's as defined

in the model have different characteristics than a DDR. A load that has variable

generation attached (such as a photovoltaic array) is still a load and has the response

constraints of a load, not a more typical battery. This would force load to fit into a less

compatible model.

2. "NGR does not have start up constraints while it operates to either consume or generate power or

switches between generating and consuming electrical energy. This simplifying assumption

eliminates the need for binary status variables." (p. 9)

a. I understand that the CAISO is trying to simplify the model, but this is not true in the

case of DR. Many DR resources essentially have a start up cost and constraints. Many

NGR resources may also have costs and constraints associated with switching from

generating power to consuming power.

b.

CAISO Answer to both questions 1 and 2:

If the intent is to model the variable generation attached to a load and/or there are costs and constraints

associated with switching from generation power to consuming power, CAISO‟s existing non

participating load with a pseudo generator model will be more appropriate to provide a feasible solution.

The NGR model has an assumption of continuous operation between generation and consumption and

does not fit well in this type of setup.

3. "The algebraic power output of a NGR is limited between a minimum and a maximum capacity.

The minimum or maximum capacities can be negative. The maximum capacity is greater than the

minimum capacity." (p. 9)

a. What is the definition of "algebraic" in this context?

CAISO Answer to question 3:

This is to say that, the schedule and dispatch will be limited between the minimum and maximum

capacity. The term “algebraic” is used to tell that the MW value can be moved between negative and

positive depending on the definitions. Chapter 6 (Appendix B) in our external business requirement

specification (V16) shall already provide better explanations using examples.

4. "For a LESR, the maximum capacity (positive) represents the MW inject to the grid when it is

discharging at maximum sustainable rate, minimum capacity (negative) represents the MW

withdraw from the grid when it is charging at maximum sustainable rate." (p. 9)

a. What is the CAISO defining as the maximum sustainable rate? What happens if the

LESR can do more than this for a reasonable amount of time?

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The maximum sustainable rate is the rate that the unit can maintain charging or discharging power while

within the stored energy limit. The NGR model essentially uses the stored energy limit to measure the

unit‟s capability to generate or consume energy. As long as the stored energy limit of the LESR allows,

the LESR is still assumed capable of operating in generating or consuming modes.

5. "DDR operates as negative generation. The maximum capacity (negative or zero) represents the

lowest load level to which it can be reduced; minimum capacity (negative) represents the

maximum load level at which it can consume energy." (p. 9)

a. Again, why constrain the DDR model to only be negative generation? If the underlying

model is both negative and positive generation, why constrain this instance of the model

to be negative generation?


Again, same as the answer to question 1 and 2, If the intent is to model the variable generation attached to

a load and/or there are costs and constraints associated with switching from generation power to

consuming power, CAISO‟s existing non participating load with a pseudo generator model will be more

appropriate to provide a feasible solution.

6. "LESR has distinct ramp rates for operating in a consuming mode (charging) or in a generating

mode (discharging). DDR has one ramp rate for curtailment and restoring the load." (p. 9)

a. This requirement makes simplifying assumptions that will likely not be valid for many

NGR resources. It is likely that all NGRs, both LESR and DDR, will have distinct ramp

rates for both charging and discharging and that these will vary through the NGR's

operating range.rhe DDR for the period." (p. 9)


Energy Storage Efficiency can be used to model the difference between the amount of energy charged

versus the amount of energy it can later discharge. Our external business requirement specification (V16)

has the definition of energy efficiency in Chapter 5 Appendix A and also the usage of efficiency in

various business rules.

7. "For DDR, the energy limits (MWh) constitute the maximum energy that can be curtailed from

the DDR for the period." (p. 9)

a. I believe that this seems reasonable, but I would be interested in the CAISO's reasoning

behind using this idea for DDR.


This is to allow market participants to tell CAISO that, this DDR resource can only be curtailed for

certain amount of energy during a certain period. For demand response, this feature can be important

because the curtailment limit can be impacted by multiple factors in real-time. This is different from a

conventional generator.

8. "LESR can provide ancillary services continuously while it is charging or discharging. The

dispatch of a LESR providing ancillary services must employ a Stored Energy Management



(SEM) scheme to manage the state of charge and ensure that there is sufficient stored energy in

the device to dispatch to satisfy the ancillary service award." (p. 9)

a. What is a Stored Energy Management scheme in this context?


This is a terminology we use to indicate the state of charge management in the system to ensure that the

ancillary service we procure can be delivered when dispatched.

9. "NGR can provide regulation from anywhere within its regulation range." (p. 9)

a. This should be modified to "A certified NGR can provide regulation from anywhere

within its regulation range."


We agree. That is the intent.

10. "NGR DDR optimal schedule shall be limited by the Curtailable Energy Limits and operation

range. The remaining curtailable energy limits are maximum energy (MWh) that can be curtailed

for the optimization horizon." (p. 13)

a. What is the optimization horizon in this context and does it vary between the IFM (24

hour look ahead and co-optimization) and the RTM (4 to 6 hour look ahead and

commitment)


Depending on REM or non REM,

1. For REM DDR, this will only be enforced in RTD horizon which includes 13 to 18 5-minute

intervals;

2. For non REM DDR, this will be enforced in IFM (24 hours), RTPD (4 to 18 15-minute intervals)

and RTD (up to 13 5-minute intervals).

11. "6. Master File shall ensure NGRs have a continuous operation range. NGR cannot be a multi-

stage generator, MSG. NGR cannot have a forbidden region." (p. 13)

a. Why is MSG not allowed with NGR? There are many instances where a MSG model is

more appropriate for NGRs than the continuous generation model.


No. Introducing MSG configurations into the NGR model will significantly increase the implementation

complexity.

12. "DAM/RTM shall ensure the NGR optimal schedule and AS awards are based solely on its

energy bid curve, including penalties for self-schedule, reserved contingent operation reserve

capacity, and exceptional dispatch as applicable. DAM/RTM shall include penalties for AS

award and AS self provision as applicable; no other costs (startup, shutdown, minimum load, or

transition costs) apply to NGR." (p. 15)

a. If there are start up constraints, then this requirement will need to be altered.




Again, same as the answer to question 1 and 2, If the intent is to model the variable generation attached to

a load and/or there are costs and constraints associated with switching from generation power to

consuming power, CAISO‟s existing non participating load with a pseudo generator model will be more

appropriate to provide a feasible solution.

13. "For DDR, DAM shall optimize DDR based on the resource's bids. In DAM, the curtailable

energy limit constraint is not enforced. RTM shall optimize DDR subject to energy limits. The

curtailable energy limits will be submitted by the DDR through EMS. If the telemetry of the

DDR's curtailable energy limit is not available, the curtailable energy limit for the RTM shall be

the default value specified in the Master File." (p. 15)

a. If the IFM does not enforce the curtailable energy limit (if one is given), then it is likely

that NGR-DDR's will not bid in their entire capability into the market for fear of financial

risk. Why can this constaint not be enforced in the IFM?


If this is necessary, we can use the DA self schedule as the reference to curtail from. This will allow

CAISO to calculate the curtailment amount when observing the curtailment limit.

14. "4. EMS shall receive NGR (LESR and DDR) telemetry of the following data every four (4)

seconds:

Maximum Operating Limit (MW);

Minimum Operating Limit (MW);

Resource Instantaneous Output (MW);

Resource Charge Rate (MW/min);

Resource Discharge Rate (MW/min);

Resource Connectivity Status (On/Off);

Resource AGC Control Status (On/Off);

State of Charge (SOC), which is the actual stored energy (MWh) remaining in the device for

LESR;

Maximum Energy in MWh

Minimum Energy in MWh




There is no question to be answered here.

15. (Option) for DDR, curtailable energy limit (CEL in MWh) remaining in the resource" (p. 16)



16. The SOC should be an option only for LESR



17. "7. DDR is modeled as a generator with negative output. DDR is connected at Cnode." (p. 16)

a. What is a Cnode in this context?


A Cnode represents the individual connectivity node that we use when model the power flow in the grid.

It typically represents the injection or ejection point of the device when it connects to the CAISO

transmission grid.

18. "OMAR shall be able to recognize and support NGR as generation resources and receive revenue

meter data. OMAR shall provide the revenue meters to settlement, using generation resource

functionality." (p. 17)

a. NGRs could be aggregated meters. Does this requirement envision a distributed

aggregated NGR?


Yes, it does. This requirement is to say that, as the same requirement we have for conventional

generators, the revenue meter needs to be submitted at the same level as they participate in the market. In

other words, in the case of distributed aggregated NGR, if that NGR is participating into the CAISO

market using one resource ID, then the revenue meter is expected at the aggregated level on that resource

ID. It is the market participant‟s responsibility to aggregate those meters up.

19. "13. Ensure the portion of the demand of NGR-REM providing Regulation Energy in any

Settlement Interval is not allocated uplift costs that apply to measured demand.


This is to say that, for the DDR electing REM, the load portion providing regulation service will not be

subject to any uplift cost allocated to measured demand. However, the load portion that does not provide

regulation service will be subject to the uplift cost just like any other measured demand.



20. Ensure NGR be eligible for Bid Cost Recovery (BCR) for the energy and AS bids. NGR is not

eligible for commitment cost recovery.


Since NGR resource can submit energy bid and/or ancillary service bids, they are eligible for bid cost

recovery like conventional generators. The reason NGR is not submit to any commitment cost recovery is

that, NGR resources are not allowed to have any commitment cost. For the demand resources that have

the need of commitment cost, please refer to answer to question 1 and 2.

21. The load represented by DDRs will be subject to the applicable cost allocation for Participating

Load.


This is to say that, for the DDR not electing REM, its entire load will be treated as participating load in

our market and have cost allocation as any other participating load.

22. 16. The positive or negative generation represented by an LESR is subject to applicable cost

allocation for generators." (p. 18)

a. The cost-allocation decisions for NGR-REM, NGR-DDR, and NGR-LESR are not

justified. Why can the cost-allocation mechanisms be (1) for consumption, as PL and (2)

for providing generation (as a generator). In this case, providing generation would be

providing generation versus the normal schedule, not simply if the value of resource is

negative (it could have been negative and become less negative due to CAISO

instruction, therefore providing generation to the grid.)


This is to say that, the NGR LESR resource will be treated as a generator when it comes to cost allocation.

For the cost allocation for a NGR DDR electing REM versus a NGR DDR not electing REM, refer to answers

to question 19 and 21.

The different cost allocations for NGR LESR, NGR DDR electing REM and NGR DDR not electing REM

resources are based on our existing and REM filing tariff, REM policy and existing participating load policy.



Original comments from PG&E external BRS Version

23. When a resource elects REM option, the regulation capacity awarded in the day ahead market is

evaluated as four times the regulation energy it can provide within 15 minutes.

Does this apply to NGR-DDR-REM?


Yes it does.

24. Could CAISO also provide the problem understanding / analysis for NGR Non-REM? Also, we

think that the issue of CAISO systems not being able to handle negative numbers should be

addressed in this section. The negative generation is the model to be used here.


Problem Understanding /Analysis

The ISO considered NGR-REM as part of the project to address the participation of non-generator resources

(NGR) in the ISO‟s energy and ancillary services market. The REM is designed to enable continuous limited

energy resources to meet the one hour duration of regulation purchased in the day-ahead market. It is also

important to note that, a NGR resource can provide energy, spinning and non-Spinning services in addition to

regulation service if it qualifies. REM is one market option that a NGR with 15-minute continuous MW basis

can choose to participate but not the only option for NGR resources.

The ISO believes that facilitating the provision of regulation by limited energy non-generator resources will

help address future system requirements under Renewable Portfolio Standard (RPS). The ISO‟s renewable

integration studies highlight the potential need for additional procurement of both regulation up and

regulation down.

The ISO considered NGR-REM within the scope of Renewable Integration: Market and Product Review RI-

MPR Phase 1. The NGR-REM enhancements to existing market products should be seen as reasonable

accommodations for the physical characteristics of different technologies that can provide regulation,

similarly to the ISO‟s efforts to improve modeling of multi-stage generation in the energy markets. The ISO

will address the participation of non-generator resources (NGR) in general in the ISO‟s energy and ancillary

services market. The NGR-REM will be a part of the expanded functions for non-generator resources (NGR).

25. Can DDR be considered a continuous limited energy resource? (See 2.3)


Yes. A DDR resource is considered a demand resource with a continuous energy limit on how much it can be

curtailed on a continuous base.

26. For DDR, its operation is as negative generation. The maximum capacity (negative or zero)

represents the lowest load level it can be reduced to; minimum capacity (negative) represents the

maximum load level at which it can consume energy.

It appears that CAISO assumes that NGR-DDR cannot go negative, but there may be several

situations where it could for example due to customer adoption of on-site generation such as

solar.




Assuming the question is about the following, can we combine an on-site generation with demand to provide

energy or consume energy. The answer is Yes, however it will be modeled as a LESR option under NGR, not

DDR. Please see Page 9, paragraph 2

27. LESR has distinct ramp rates for operating in a consuming mode (charging) or in a generating

mode (discharging). DDR has one ramp rate for curtailment and restoring the load.

Does this mean that an LESR can have multiple rate rates depending on the operating range? Also,

why would a DDR be limited to only one ramp rate for positive and one ramp rate for negative?

CAISO Answer to question 27: LESR is limited to one ramp-rate in the positive range and one ramp-rate in the negative range. For DDR, it is

limited to a single ramp-rate.

28. NGR is typically an Energy-Limited Resource (ELR);

For an LESR, the energy limit (MWh) is the maximum energy the device can store; it can be

discharged to generate electricity. Based on an initial stored energy, the continuous energy

consumption or generation is constrained by the Maximum Stored Energy Limit, accounting for

inherent losses while charging and discharging.

For DDR, the energy limits (MWh) are the maximum energy the DDR can be curtailed to for the

day. (p 4)

We are not certain that that this is the best measure of how DE is functionally limited in operation.

CAISO Answer to question 28: For DDR, the energy limits (MWh) constitute the maximum energy that can be curtailed from the DDR for

the period. This is one limit we can use. MPs can define a continuous curtailment limit instead of daily

depending what you need there.

29. LESR and DDR can provide energy and Ancillary Services (AS).

LESR can provide Ancillary Services (AS) continuously while it is charging or discharging. The

dispatch of an LESR providing AS must employ a Stored Energy Management (SEM) to ensure

that there is sufficient stored energy in the device to dispatch the AS when they are called upon.

(p 4)

Please define Stored Energy Management. How is this different than SOC? Also this only refers

to LESRs, what about DDRs.

CAISO Answer to question 29: The definitions of Stored Energy Management and State of Charge are in the chapter 5, Appendix A of

the external business requirement specification V16.

The dispatch of a LESR providing ancillary services must employ a Stored Energy Management



(SEM) scheme to manage the state of charge and ensure that there is sufficient stored energy in the

device to dispatch to satisfy the ancillary service award.

DDR will be limited by curtailable energy limit (CEL) to ensure that there is enough energy to be curtailed to

support the ancillary services.

30. NGR resources will be subject to ancillary service No Pay based on the device energy limit.

What does this mean? How will no pay be enforced as it relates to the Energy Limit?

CAISO Answer to question 30: Please refer to REM-BRQ0920, BRQ0930, BRQ0932, BRQ0933, BRQ0935 in the external business

requirement specification V16.

Essentially, CAISO will use the state of charge value from PI to evaluate whether the awarded ancillary

service for a particular interval can be dispatched. The ancillary service amount that is not dispatch-able will

be subject to No Pay.

31. Manage the NGR-REM Energy Offset through the Stored Energy Management in Real Time

Dispatch (RTD) market for regulation, constrained by the NGR-REM energy level, i.e. State of

Charge (SOC), charge rate and efficiency.

Please define “offset” in this context.


The offset in this context refers to the need for a NGR-REM resource to consume or supply energy in order to

stay at a level of the state of charge so to maximize the available regulation capacity it can provide.

32. The NGR model applies to the resources that subject a limited energy constraint to provide

energy and ancillary services. NGR resources such as flywheels, batteries, and some demand

response resources will require a real-time energy offset; whereas, a traditional hydro or thermal

unit does not.

The NGR will be subject to the capacity and operation range limits similar to the generator. However,

the NGR operating range can be negative. The negative production from NGR represents the status

that NGR withdraw energy from the grid. In addition, the NGR ability to provide energy and ancillary

services will depend on the NGR device stored energy level (for LESR) or load curtailment limits (for

DDR) and the device ramp (charge/discharge) rate and efficiency.

This is mentioned in the context of managing LESR. Will this be available for NGR-DDR?


DDR shall be managed by enforcing the curtailment limit. Please see BRQ0720 in the external business

requirement specification V16.



33. Master File shall ensure the NGR have continuous operation range. NGR cannot be a multi-stage

generator, MSG. NGR cannot have forbidden region.


Correct. The NGR model does not allow a MSG configuration type of modeling.

34. DDR is modeled at a Cnode, the same participating load with negative generation.

What is the definition of a CNode here?


A connectivity node we use in current market design to model an injection or ejection point in the network

model. This particular statement above does not change anything that we are currently doing.

35. 3. SIBR shall support REM (defined by REM FLAG) resource to bid in or self-schedule

regulation up and regulation down in DAM/RTPD.

Did CAISO mean Self-Provide instead of self-schedule?


Yes, it means self provided regulation up or regulation down.

36. Outage Management System (OMS):

Did CAISO mean SLIC?, or is it expected that OMS will be available for the REM/NGR

implementation (including market simulation)?


Yes, it is SLIC. OMS is indeed the planned replacement of SLIC.

37. OMS shall support NGR DDR to register its unavailability. (Note that DDR unavailable does not

equivalent to DDR load offline. A DDR‟s unavailability is used to indicate that this DDR is no

longer capable of responding to economic load curtailment from the markets.

Market will set the DDR at its self-schedule level in DAM, set at telemetry in RTM and

disqualify all the AS self provision and awards.) The CAISO will use telemetry to set the

operation condition of the NGR-DDR in the RTM? Exactly what information will be used here

and how will it be used?


The DDR declared out of service means no demand response. However, the DDR can still consume energy.

There is no outage for the demand consumption. The above statement specifies how to set DDR consumption

level in the case that a DDR register out of service in SLIC.



38. In RTM, the NGR without bids or self schedules shall be modeled as unavailable, unless it has a

nonzero State Estimator (SE) solution, in which case it is subject to the No Bid and Compliance

logic, or unless it has an active Exceptional Dispatch (ED) instruction.

Please provide an example. This seems inconsistent with how the CAISO proposed to treat NGR-

DDR a few points earlier.


Please see BRQ0620 in the external business requirement specification V16. This is consistent with the DDR

treatment because we consistently set dispatch (DOT) equal to telemetry in such events.

39. DAM will assume LESR (non REM) SOC initial state at daily initial SOC.

Please explain. Does CAISO mean a SOC is needed every day? How will CAISO establish a SOC

every day? This seems like a fairly large assumption that will probably not be correct in actual

operations.


Daily initial SOC is submitted by MP and will be used for the IFM run. Due to the nature of day-ahead run at

10:00am prior to the actual operation day, the initial condition can be different from actual operation.

However this at least gives the MPs a chance to tell the likely outcome.

40. RTM shall receive from EMS the latest SE solution and telemetry for each NGR including the

actual SOC for each LESR, and shall use this information to calculate the initial condition for

each LESR.

This assumes that all NGR-LESR will have telemetry.


Yes, based on CAISO policy, all NGR resources providing ancillary services need to have telemetry

available.

41. SOC shall be published in the schedule payload, historical tables, and the save case along with the

schedule.

Is this for the CAISO‟s EMS consumption?


No. This requirement does not have any external impact. It is to make sure that the SOC can be

communicated to CAISO internal systems including RTM, MQS etc. to perform their individual functions.

42. What are the telemetry requirements for DDR? Are all of these required to be submitted every 4

seconds? Some of these look to be defined in the Master File.




The telemetry requirements are the same as generators. Please see BRQ0260 in the external business

requirement specification V16 for a complete list.

43. Instantaneous Output (MW) measure the operation state of NGR. The Instantaneous Output

(MW) for LESR is positive when LESR is discharging, negative when LESR is charging. The

Instantaneous Output (MW) is negative for DDR. (p12)

How is this feasible? Is it the total load of the DDR? Again, this assumes that the DDR cannot go

positive.


A NGR-DDR is assumed that such a load can be individually measured and controlled in real-time. As such,

it shall be able to do that. This is the fundamental difference from other demand response offering such as

PDR.

44. The SE solution shall include the estimated output for each NGR based on its telemetry.

Is this consistent with how other resources are estimated in the SE?


Yes.

45. DDR is modeled in SE as a generator with negative output. DDR is connected at Cnode.

What is a Cnode as defined in this context?


A Cnode is a connectivity node that represents an ejection point in the network model because it is a demand.

46. How will the ramping energy be handled?

Why would Pumping Energy not be applicable to some NGRs?


Ramping energy will be calculated in the same way for generators except that it will need to handle the cases

in which DOP and day-ahead schedules can be positive or negative. Since the DOPs are assumed to be

positive or negative and expected energy will be calculated relative to the day-ahead schedules from DOPs,

the expected energy will be derived based on the algebraic difference between those data along with the

limits. As such, the original pumping energy is not needed here. Pumping energy will continue to be

calculated for pump storage or pumps. When a NGR is consuming energy, its expected energy will be

calculated accordingly with negative sign depending on the combination of LMP, limit, DOP, etc. as in the

case of generators.



47. NGR shall be eligible for Bid Cost Recovery for its Energy/AS bids; there is no commitment cost

recovery for NGR.

Why are NGRs not available for commitment cost recovery?


At this phase of implementation, we will not model commitment cost in the market for the NGR resources

and as such, there is no BCR for commitment cost.

48. OMAR shall be able to recognize and support NGR as generation resources as revenue meters

come in and provide the revenue meters to settlement, using generation resource functionality.

This statement is unclear.


This is simply saying that the OMAR shall function the same way as it is today when dealing with metering.

In current production, a generator can have negative energy produced due to auxiliary load as well.

49. The positive or negative generation represented by LESR are subject to applicable cost allocation

same as generator.

How will ISO allocate these, will neg be a load, etc or is it net neg dev as for gen?


It will be treated as negative generation when the LESR is consuming energy. The positive and negative

generation will be allocated exactly like a generator except that the negative energy below zero can be

associated with energy bid prices.

50. REM-BRQ0001 NGR resources that operate as generation and load but have a MWh limit to

generate, curtail or consume Energy on a continuous basis must sign a PGA and a PLA.

Will all NGRs need to sign both a PGA and PLA?


NGR-LESR needs to sign PGA and PLA. NGR-DDR needs to sign PLA.

51. REM-BRQ0010 1. Only the resource that requires a real-time energy offset to provide regulation

can select REM; Such as flywheels, batteries and some demand response resources.

How will the CAISO determine which types of resources require a real-time energy offset to provide

regulation? How will this interact with a potential RTIS and the redefinition of regulation in the

Renewables Integration Initiative Phase 2? Also, why would the CAISO impose such a constraint?




CAISO will require all units with that kind of constraints to register with us as the physical constraints. This is

no different from a generator required to register their minimum up time or down time IF exists. Also please

keep in mind. This does not conflict with Renewable initiative. Under no exception, CAISO will not procure

capacity or energy knowing such energy or capacity do not exist. That is why we observe the energy limit as

constraints.

If there is no physical energy limit for a NGR resource, then it does not have to be registered with an energy

limit and hence the market will not enforce that constraint when procuring energy and/or ancillary service

from that NGR resource.

52. REM-BRQ001. The ISO shall conduct the regulation certification process to ensure NGR-REM

is certified for provide regulation services. The NGR-REM must meet 10 minute ramping

requirement, same as generator. The regulation up capacity must meet the 15 minute continuous

energy deliver requirements when it is fully charged; and regulation down capacity must meet the

15 minute continues energy consume requirements when it is completely discharged

Did CAISO mean “Continuous”? This seems reversed. Also the storage Capacity has nothing to do

with the criteria This requirement makes the assumption that that energy charge and discharge rates

are the same across the entire range of a NGR‟s state of charge. What if the charge or discharge

rates are not the same, i.e. what if a NGR could discharge 20MW at 50% SOC and 10MW at 15%

SOC?


Yes, “Continuous”. The certification requirement of NGR-REM regulation capacity is based upon the

maximum amount of energy which can be delivered and consumed over a fifteen minute interval. No

assumptions are made for any other operation characteristics. This is based on CAISO REM policy. If a

particular device does not meet this requirement, it can still be a non-REM NGR resource to provide

regulation energy.

53. A fully charged 5 MWh storage can provide maximum 20 MW to the grid for 15 minute

continuously. The storage will be certified for 20 MW regulation up capacity.


BRQ0015 in the external business requirement specification V16 will give a better example to what are the

certified capacity under different scenarios and products.

54. REM-BRQ0012 The NGR agreement shall generally include participating generation and/or

participating load agreements for NGR. For the NGR (Non REM), they will subject to existing

ISO requirements for the traditional generator to certify the capacity for regulation, spinning,

non-spinning and maximum capacity.

Is the NGR Agreement available? Also why is a PGA, or PLA needed if there is an NGR agreement

(BRQ0001)?




BRQ0012 in the external business requirement specification V16 has corrected this. For LESR, we need both

PLA and PGA to be signed; For DDR, we need PLA to be signed. There is no separate NGR agreement there.

55. REM-BRQ0014 For DDR (Non REM), the certification criteria for generation resource is

applicable. DDR cannot inject power to the grid, therefore, the operation range will be non

positive. The Pmin will be negative, represent the maximum load level. The Pmax will be

negative or zero, represent the minimum load level can be curtailed to. Pmax =0 means the load

can be totally shut down. Pmin to Pmax will be the curtail-able load range.

CAISO should consider the case where a DDR resource can inject power to the grid.


As we explained earlier, if a demand combined with Solar, for example, is providing services to CAISO, the

whole plant can be modeled as a LESR.

56. REM-BRQ0020 Master File Resource Data Template (RDT) shall to allow Scheduling

Coordinators for NGR as a subtype (GEN_TECH) of generation resource with negative to

positive operating range. SC must submit NGR default values of the attributes to ISO using the

existing manner. The template shall include the identifier for NGR Limited Energy Storage

Resource (LESR) or Dispatch-able Demand Response (DDR) (FUEL_TYPE).

Please clarify.


Those fields are internal attributes that CAISO uses to communicate the types and relevant attributes of a

particular resource. CAISO will publish exact RDT format for market participants to use to register their

NGR resources.

57. REM-BRQ0080 Master File should ensure NGR not have start up cost, start up time, minimum

up time, minimum down time, forbidden regions, and transition time.

Why is there no start up cost? Also for forbidden regions, there are operation constraints that

should be considered. Why are forbidden region and transition time not allowed for NGR?


This is our first phase of implementation that we have the simplified assumptions. In future modeling and

release, we can contemplate more constraints if such needs are warranted.

58. REM-BRQ0090 Master File should ensure NGR not register as multi-stage generator (MSG).

Why is MSG not allowed for NGR?






59. REM-BRQ0110 NGR shall have a registered maximum capacity (Pmax); Pmax can be positive

for LESR, zero or negative for DDR.

The positive case should also be considered for DDR


As we explained earlier, if a demand combined with Solar or so is providing services to CAISO, the whole

plant can be modeled as a LESR.

60. REM-BRQ0114 Master File shall ensure that maximum operating capacity ≥ upper regulation

limit ≥lower regulation limit ≥ Minimum operating Limit.

We know that the amount could go higher.


This is the same limitation we have for regular generators.

61. REM-BRQ0120 LESR may have up to two segment ramp rate curve with Pmin (<0) to 0

(negative side) as first segment, 0 to Pmax (positive side) as second segment. An LESR can also

define a single segment from Pmin to Pmax if applicable.

Is 2 enough? Why is the CAISO limiting to 2 segment ramp rate curves?



release, we can contemplate more constraints if such needs are warranted

62. REM-BRQ0120 For the DDR, the ramp rate will be one segment curve for Pmin to Pmax

Is 1 enough? Why is CAISO limiting the number of segment curves to 1?




63. REM-BRQ0141 Master file shall allow NGR DDR to register the daily maximum demand

response and daily minimum consumption energy limit.

How will this be done? What does CAISO mean by daily? Does the Master file need to be updated

daily?




The daily limit can be registered. When the daily maximum demand response is registered, market will ensure

that the daily total load curtailment amount will not exceed that limit. When the daily minimum consumption

energy limit is registered, market will ensure that the daily total load consumption will be at lease at that limit.

64. REM-BRQ0150 Master File should define NGR not subject to local market power mitigation

(LMPM)

What about the consumption side?


Same. They are not subject to power mitigation.

65. REM-BRQ0160 NGR can be an aggregated resource. Master file must define the distribution

factors (GDF) for Aggregated NGR.

Will the components for the resource be in the same location? (e.g. same SLAP)


Yes. They at least have to be within the same sub LAP.

66. REM-BRQ0182 NGR AS award/self-provision optimization flag shall be set („Y‟) for final

qualification in the optimization engine

What is the purpose of this flag?


This is the same as generators. This is to tell the market systems to be able to perform the qualification

process to validate whether the AS are operational feasible.

67. REM-BRQ0211 NGR as a generation resource with positive or negative power injection; similar

way model the pump hydro generators for LESR and Pump model for DDR. The difference

between NGR and the Pump Storage model is that, the NGR will use a single GDF set for both

positive and negative.

Will there be a GDF for negative transactions?

Please describe and provide examples


Yes. There can be GDF for negative transactions. The GDF is used to distribute the power to individual nodes

when the resource itself represents an aggregate resource. Again, this is the same methodology CAISO uses

currently for aggregated generation.



68. REM-BRQ0250 For LESR, the ramp rate (discharge rate) shall apply to the LESR positive

operation range, either LESR increase MW output or decrease the MW output. The LESR shall

inject the power into the Grid, running at discharge mode.

What is the implication?


The implication is that, the resource will have the same ramp-rate for either increasing energy supply or

decreasing energy supply as long as the resource is supplying energy. This is the same method CAISO uses

for generation today. In other words, there is no difference for ramping up versus ramping down for the same

capacity range.

69. REM-BRQ0250 4.The ramp rate (charge rate) shall apply to the LESR negative operation range,

either LESR consume more MW or less MW. The LESR shall consume the power from the grid,

running at charge mode.

What is the implication?


The implication is that, the resource will have the same ramp-rate for either increasing energy consumption or

decreasing energy consumption as long as the resource is consuming energy. This is the same method CAISO

uses for generation today. In other words, there is no difference for ramping up versus ramping down for the

same capacity range.

70. REM-BRQ0250 For DDR, a regulation up will equal to load reduction and regulation down will

equal to load increase, the ramp rate shall apply to either load reduction or load increase.

Batteries can do this too.


Yes. We do plan to do that for the Battery.

71. REM-BRQ0262 DDR Instantaneous Output (MW) telemetry is negative for its load level. DDR

Instantaneous Output (MW) telemetry is zero if the load shut down totally.

If a renewable resource is “behind” the DDR, the amount can be positive


As we explained earlier, if a demand combined with Solar or so is providing services to CAISO, the whole

plant can be modeled as a LESR so to be able to provide generation or demand.

72. REM-BRQ0330 The 10-minute upward capacity shall be available to SAMC for spin/non-

Spinning No Pay calculation.

This requirement is unclear. Please clarify.




The upward capacity means regulation up, spin and non-spin.

73. Business Process: < Manage Outage Management System (OMS)>

Does CAISO mean SLIC? Is it correct to assume OMS will not be available till then?


Yes. OMS is the new application that we are planning to replace SLIC in future. The SLIC will continue to be

used to manage the outage before OMS go live.

74. REM-BRQ0362 OMS shall support input of Pmin and Pmax to accept negative value.

Please split this BRQ into one for negative Pmin and one for negative Pmax


The requirements are changed. No negative number input for OMS/SLIC. Please see BRQ0380 and

BRQ0381 in the external business requirement specification V16.

75. REM-BRQ0391 OMS shall support NGR DDR to register its unavailability. This status is in

addition to the out of service status (Y/N) to indicate the DDR is no longer capable of responding

to load curtailment.

Please add: and unavailable for load consumption for regulation down


Yes, the out of service status will do that as well. Basically the out of service status is to tell the market that

this DDR cannot provide any ancillary service or respond to energy dispatch.

76. REM-BRQ00401 The load consumption related to any NGR DDR needs to be excluded from any

DLAP or CLAP load forecast.

Does this mean a Load Serving Entity would not need to remove the NGR from its overall load

forecast and that the CAISO systems will do this automatically?


No. It means that a load serving entity shall remove it from its total load forecast just as CAISO will do as

well.



77. REM-BRQ0441Using NGR DDR model for demand response, the MW award is for the demand

load level. The curtailment itself is implied by the difference from the energy MW award to the

Lower Economic Capacity (LEC).

Please clarify and provide examples. Isn‟t the award already a delta?


Award DOT is the load level represented as absolute MW, not the curtailment. So when a DDR is dispatched

at -5MW, it tells the load to consume energy at the 5MW level.

78. REM-BRQ0460 SIBR shall ensure DDR must submit self schedule for the lower operation limit.

We do not understand what this means Please clarify. Please define the lower operational limit

(LEC? Pmin? Absolute lowest?) What markets?


The self schedule tells the base load that the DDR can do and curtail from. Applicable to both day-ahead or

real-time. Section 6.5 in the external business requirement specification V16 gives a detail example.

79. REM-BRQ0520 Maximum Energy Limit is to tell the maximum load curtailment amount that

this DDR can respond to.

Please clarify. This is confusing as the curtailment is a delta.

Please define the two terms.


Changed, please see BRQ0720 in the external business requirement specification V16 for the exact detail.

Yes, in this rule, the limit is observed as how much maximum the load can be curtailed (as a delta).

80. REM-BRQ0541 SIBR shall support LESR to submit initial operation point SOC (MWh) for each

trading day in DAM.

How is the value used.? There may not be a correlation to RTM.

CAISO Answer to question 80: This value is used as initial condition in DAM. Yes, it is understood that this may not be the same value as to

RTM.

81. REM-BRQ0562 Minimum consumption (Emin) and Maximum Demand Response (Emax)

Please add unit of measure (MWh)



CAISO Answer to question 81: Yes, this rule in the external business requirement specification V16 has been changed to include

MWH as the unit of measure.

82. REM-BRQ0570 DAM and RTM shall support NGR as subtype (GEN_TECH) of generation

resource with negative to positive operation range.

Did you mean Lower to Higher?

Is this both for LESR and DDR?

CAISO Answer to question 82: Yes for both questions.

83. REM-BRQ0590 DAM and RTM will not model start up, minimum up time and minimum down

time constraints for NGR. No binary commitment decision variables are needed for NGR.

Please explain why start up, minimum up time and minimum down time will not be modeled for

NGR

CAISO Answer to question 83: This will be very difficult to observe given the energy limit constraint. However, we can model in the future

for future releases if there is a need.

84. REM-BRQ0600 DAM and RTM shall model NGR with energy and/or AS bids as online resource

unless it declared unavailable. There is no start up cost and no start up time associated with NGR.

Please explain why there is no start up cost and no start up time for NGR.

CAISO Answer to question 84: First phase assumption.

85. REM-BRQ0631 If DDR declared out of service from OMS, RTM shall de-commit DDR

resource.

What does the second statement mean?

CAISO Answer to question 85: This rule has been refined. Please see BRQ0631 in the external business requirement specification V16. It

means that the DDR is no longer capable of providing ancillary services or responding to energy dispatch.

86. REM-BRQ0650 AS awards for DDR with declared unavailability shall be disqualified; no matter

the existing level of load. Please explain why



“no matter the existing level of load”

CAISO Answer to question 89: By declaring out of service, DDR will not response, even the DDR still consume energy, it will not be able to

respond load increase or curtailment by CAISO to provide AS.

87. REM-BRQ0710 4. In DAM, set initial SOC(0) equal to Initial operation point (inputted through

SIBR by SC) at a State of Charge level:

What will CAISO do if the Physical value is different? This looks like a BCR exploitation

opportunity

CAISO Answer to question 87: Yes, we need to rethink a bit. The initial reason we are doing this is that, it is difficult for CAISO to know

what the SOC is on a day-ahead base. This is different from real-time in which EMS will provide that through

telemetry.

88. REM-BRQ0712 1. The SOC constraints will be enforced for all the intervals of the optimization

horizon in IFM. The initial SOC in DAM is an input by SC through SIBR.

What if the SC does not put in the initial SOC?

CAISO Answer to question 88: System will assume based on the previous IFM results on previous trade days.

89. REM-BRQ0813 The ex-post capacity formula shall be the same as for generators. It has to

accommodate the fact that NGR ‟s limits and curves can be across positive and negative, the

NGR can change from positive (discharging) to negative (charging) and reverse output

continuously between adjacent intervals.

Is this true for DDR as well?

CAISO Answer to question 89: Yes.

90. REM-BRQ0920 It is important to note that, a review of current implementation is needed to

ensure that, the business intent is met when a negative schedule and/or a negative limit are

existent.

When will this review be done?

CAISO Answer to question 90: It has been done.



91. REM-BRQ1100 REM resources and the regulation procurement from REM.

Please provide the details of this monitoring

CAISO Answer to question 91: This is about monitoring the market performance when these resources are introduced in the new market. We

can provide more details when we reach that point.

Documents

Non-Generator Resources - Regulation Energy Management