Ancillary Services Marketat Watt-Ex

2

WHAT ARE ANCILLARY SERVICES?

Maintain stability of electricity grid

Dispatched by the System Controller (AESO) to balance changes in supply and demand

Supplied by facilities that meet technical specifications set out by the System Controller

Regulating Reserves

Spinning Reserves

Supplemental Reserves

3

ANCILLARY SERVICES CONTRACTS

Active StandbyMarket:

Commodity:

Instrument: Day -1 Day -2 Day -3 Day -4 Day -5

Base Load Off Peak On Peak

Regulating Spinning Supplemental

4

ANCILLARY SERVICESEXCHANGE STRUCTURE

Watt-ExAS Contracts

Load &Generation

AESOCommercial Group

AESOSystem Controller

merit order

$ $

offers bids

trade data & unit position

compliance data

compliance & settlement

dispatch & directives

response

5

NON-PERFORMANCE

Trade cancellations prior to performance

Trades in Error

Trades that do not meet AESO standards

Overcommited units

Events of Force Majuere

Non-performance

Events of Force Majuere

Non-compliance

6

QUESTIONS