Controllable Generation UCAP determination

Eligibility WG – September 12, 2017

Purpose and objective

The objectives of this presentation include:

• Recap the installed capacity (ICAP) and unforced capacity (UCAP)

definitions

• Understand the data requirements for UCAP

• Compare GADs and AESO data

• Request feedback from workgroup

1

Recall – from July 4th meeting

UCAP Calculation for a Thermal Resource

Example:

• Gas Combined Cycle with a

nameplate capacity of 500 MW

• Seasonal Net Dependable

(ICAP) accounts for the impact of

ambient weather conditions

(Summer) on unit performance

• Unforced Capacity (UCAP) is the

ICAP value of the unit reduced

by its recent actual forced outage

rate during system demand

periods (EFORd)

• Generator will able to offer 396

UCAP MW into the capacity

auction

2 Public

Nameplate capacity rating = 500 MW

Nameplate capacity modified for seasonal ambient limitations (ICAP). Example: If ambient temprature reduction is 10 % of the nameplate capacity.Ex.ICAP = 500 MW * 90% = 450 MW

UCAP= ICAP * (1-EFORd)Forced outage rate = 12%UCAP = ICAP * (1- forced outage rate) Ex. If UCAP = 450 MW * (1- 0.12) = 396 MW

UCAP calculation and data requirements

• UCAP= ICAP x (1- EFORd) where

Equivalent Demand Forced Outage Rate (EFORd) is a measure of

probability that a generating unit will not be available due to forced outages

or forced derates when there is a demand on the unit to generate*

The EFORd calculation relies on reliability data that comes from the

Generation Availability Data System (GADS).

GADs data are collected by NERC and provide information about the

performance and outages / derates of generating units**

The UCAP calculation may have different data requirements for

uncontrollable and controllable generation

AESO does not have GADS data

*PJM Capacity Market/ PJM Manual 18/PJM Capacity Market Operations http://www.pjm.com/~/media/documents/manuals/m18.ashx

**http://www.nerc.com/pa/rapa/gads/pages/default.aspx

3

UCAP Calculation:

ETS data deficiencies

Information needed for calculating

UCAP based on EFORd

Do we have

this

information?

Comments

Duration of Forced outages,

Planned Outages, Forced Derates

and Planned Derates

NO ETS gives the option to the participants to leave out

the event type in their submissions within a 7 day

period before the event. In the case that they do not

submit this field, it would be automatically populated

using a logic that does not allow participants to clearly

distinguish between forced and planned events.

Therefore the event field would not be useful in

determining the type of the outages and derates.

Service Hours (The period of time

that the unit was generating

electricity)

Yes This could be extracted from the metered volumes.

Reserve Shutdown ( the period that

the unit was available, but not

dispatched)

Yes When the unit is available (AC ≠ 0) but generation is

zero.

Number of Actual Starts and

Attempted Unit Starts

NO The data are not available.

4

Based on the data currently available, calculation of UCAP based on EFORd methodology will be

time consuming and complex. This methodology needs information similar to what GADs provide.

However, this method could be used in the future if the GADS data become available.

Conceptual differences between AC and

UCAP

5

Ambient temp and

humidity

adjustment

30 MW

Planned

Outages/derates

40 MW

+

Available

100 MW

Maximum

Capability = 200

MW

ACf: is 140MWs

AC = 100 MW

AESO AC data does

not separate between

ambient, forced or

planned outages.

AC accounts for all

lost generation

ICAP = 170 MW Forced

outages/derates

30 MW

PJM based UCAP for thermal

generator = 140 MW

UCAP: ICAP after capacity reduction due to forced outages and derates

AESO ACf: ICAP after capacity reduction due to implied forced outages and implied derates

AESO AC: ICAP after capacity reduction due to forced outages and derates and planned outages

UCAP is ICAP adjusted for

performance through GADS

data

In other jurisdictions

This example is for illustrative

purposes only

PJM

Ambient temp and

humidity

adjustment

30 MW

Planned

Outages/derates

40 MW

Available

Capacity (AC in

ETS)

100 MW

Forced

outages/derates

30 MW

Alberta Maximum Capability = 200 MW

Questions for the workgroup discussion

• Which option should be used for the interim UCAP

calculation?

– A NERC mandate for 20MW and greater generators: do Alberta

generators follow this requirement and have GADS data?

• Is the quality robust enough for use for UCAP Calculation?

• Are categorization practices comparable for all generation owners?

• Approach for generators less than 20MWs?

– If In the event ETS data is used, should AESO prioritize

classifying outages earlier for the purpose of calculating more

accurate UCAP on time for delivery during the transition period?

– Should the AESO investigate GADS further?

– Use GADS, AC or ACf for UCAP calculations?

– What demand hours should be used?

6

Thank you

Appendix B

AC and ACf – Overview

Option 1: Use Available Capability as

UCAP

Option 2: Use Available Capability that

only includes forced outages/derates but

excludes planned outages (ACF)

For existing resources this option uses

historically submitted AC

Variable resource may use capacity factors

New resources and technologies may use

class averages either from historical available

capabilities or from sources outside the AESO

for units with no historical data

Seasons and demand hours will need to be

defined

For existing resources this option uses

historical AC submissions

ACf may be calculated using a derate factor

that only takes into account hours with forced

outages and derates

Forced outages are any outages/derates

submitted within 7 days. Any submissions

before 7 days are assumed to be planned

Variable resource may use capacity factors

New resources and technologies may use

class averages either from historical available

capabilities or from sources outside the AESO

for units with no historical data

Seasons and demand hours will need to be

defined

8

Appendix B

AC and ACf – Advantages

Option 1: Use Available Capability as

UCAP

Option 2: Use Available Capability that

only includes forced outages/derates but

excludes planned outages (ACF)

Simple to understand and implement

Availability of historical data

Provides a conservative estimate of a plant’s

true capability as it includes planned and

forced outages. Historical performance can be

measured

Rules and compliance procedures in place to

evaluate quality of AC submissions

This approach is closer in nature to way

UCAP is calculated in North American

capacity markets using GADs data

Transition to GADS may be smoother as the

difference in UCAP and ACF volumes may be

lower

9

Appendix B

AC and ACf – Disadvantages

Option 1: Use Available Capability as

UCAP

Option 2: Use Available Capability that

only includes forced outages/derates but

excludes planned outages (ACF)

Determining true availability of a unit will

require additional work as some units may

show full AC but not be dispatchable i.e. Long

lead time, Mothball, peaking units, etc.

AC data and rules were designed to meet the

needs of an energy-only market and were not

intended to fulfill the requirements of the

UCAP calculation

More complex to implement as it requires

parsing the data into planned and forced

outages, which requires assumptions

ACF will still be based on AC submissions,

which were designed to meet the needs of an

energy-only market and were not intended to

fulfill the requirements of the UCAP

calculation

Methodology requires defining an approach to

account for the impact of ambient weather

conditions

Method is still under investigation. AESO

needs to further examine AC submission data

to assess feasibility

10

Appendix B

AC and ACf – Example

11

• This example is only for illustrative purpose

• It intends to show the expected differences in magnitude between AC and

ACf

• It uses a dummy generator with a maximum capability equal to 452 MW

• The same data set was used to calculate the AC and ACf values

• For the purpose of this example, the summer season comprised months

from May to October and the winter season covered the months from

November to April

• The actual months and HEs to be used in the UCAP methodology are yet

to be decided

Appendix B

AC and ACf – Terminology

12

Forced Outage Hours - FOH

Sum of all hours experienced during Forced Outages. Forced outages are any outages submitted within 7

days.

Equivalent Forced Derated Hours – EFDH

Forced derates are any derates submitted within 7 days. Each individual Forced Derating is transformed into

equivalent full outage hour(s). This is calculated by multiplying the actual duration of the derating (hours) by

the size of the reduction (MW) and dividing by the Maximum Capacity (MC). These equivalent hour(s) are

then summed.

(Derating Hours x Size of Reduction*)/ MC

NOTE: Includes Forced Deratings during Reserve Shutdowns (RS).

Service Hours – SH

Sum of all Unit Service Hours

Equivalent Forced Derated Hours During Reserve Shutdowns – EFDHRS

Each individual Forced Derating or the portion of any Forced derating which occurred during a Reserve

Shutdown (RS) is transformed into equivalent full outage hour(s). This is calculated by multiplying the actual

duration of the derating (hours) by the size of the reduction (MW) and dividing by the Maximum Capacity

(MC). These equivalent hour(s) are then summed.

(Derating Hours x Size of Reduction*)/ MC

Appendix B

AC and ACf – Example

Option 1: Use Available Capability as

UCAP

Option 2: Use Available Capability that

only includes forced outages/derates but

excludes planned outages (ACF)

13

𝐷𝑒𝑟𝑎𝑡𝑒 𝐹𝑎𝑐𝑡𝑜𝑟 =𝐹𝑂𝐻 + 𝐸𝐹𝐷𝐻

𝐹𝑂𝐻 + 𝑆𝐻 + 𝐸𝐹𝐷𝐻𝑅𝑆× 100%

𝐴𝐶𝑓 = 𝑀𝐶 × (1 − 𝐷𝑒𝑟𝑎𝑡𝑒 𝐹𝑎𝑐𝑡𝑜𝑟)

Derate Factor AC f

Summer 2.67% 440

Winter 4.25% 433AB1

Avg AC Median AC Max AC Min AC

Summer 416 452 452 0

Winter 414 452 452 0AB1