Vice President Operations, Chief Operating Officer

DRAFT August 11, 2009

Ken Koslik Vice President Operations, Chief Operating Officer Independent Electricity System Operator 655 Bay Street Toronto, Ontario. M5G 2K4

Dear Mr. Kozlik;

Re: Dispatch of DR3 Resources

Further to the OPA letter of July 8, 2008 concerning dispatch of DR3 resources, please be advised of the following additional protocols, to be applied only after it has been determined by the IESO that based upon Supply Cushion triggers, issuance of either a Standby Notice or Activation Notice would have otherwise been required:

1. Concerning issuance of a Standby Notice, the IESO shall check to ensure that the forecasted price for electricity for all of the Hours of Availability, is not less than the Floor Price, whereby such Standby Notice shall be cancelled;

2. Concerning issuance of an Activation Notice, the IESO shall check to ensure that none of the following conditions are present which shall result in cancellation of such Activation Notice: - the forecasted price for power for all hours of the Contract Dispatch Period is less than the Floor Price; - nuclear units, with or without Activation of DR3, are projected to be the marginal unit during the Contract Dispatch Period; - Hydro-electric units are projected to spill water during the Contract Dispatch Period.

3. Should the IESO cancel any Standby or Activation Notice based upon any of the above protocols, the IESO shall formally notify the OPA of such decision, and the corresponding reason(s). Such correspondence shall be issued by the IESO to the OPA at the time of making such decision.

4. The OPA shall provide the IESO a Floor Price as often as may be required.

Thank you for your continued assistance in operationalizing the DR3 resources.

Sincerely; Paul Shervill Vice President Conservation

Cc; Sean Brady, OPA Cliff Poyton, OPA David Robitaille, IESO Diljeet Singh, IESO Mark Wilson, IESO