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