October 24, 2014 Dear Stakeholder, Re: Thickwood Hills 240 kV Transmission Development and Reactive Power Reinforcement – Update I am writing to inform you about a change to some information we sent earlier this year. In April we sent out a newsletter describing the need for new transmission development in the Fort McMurray area. In the newsletter we explained that a new 240,000 volt (240 kV) substation and new 240 kV transmission lines are needed in the Thickwood Hills area to connect the Fort McMurray 500 kV Transmission project to the grid. We also explained that new equipment is needed to better manage voltage in the area. This new equipment is needed in the new Thickwood Hills substation, and also in the existing Quigley and Engstrom substations. However, after further consideration, we have determined that the new equipment needed in the Quigley and Engstrom substations will no longer be included in this application. We will include this equipment in a future application instead. Please refer to the maps on the next page for further clarification. The original newsletter we sent out in April can be found at www.aeso.ca/thickwood We plan to the file this application later this year or early in January 2015, under the new name Thickwood Hills 240 kV Transmission Development. Please contact us at 1-888-866-2959 or [email protected] if you wish to discuss this information further. Yours truly, Matt Gray Corporate Communications Page 1 Public Thickwood Hills 240 kV Transmission Development April 2014 October 2014 The map on the top appeared in our Thickwood Hills 240 kV Transmission Development and Reactive Power Reinforcement newsletter which we sent out in April of this year. The green shaded area on this map shows the approximate area where transmission developments are needed. It also shows substations south of Fort McMurray where new equipment is needed to support voltage in the area. The need for this voltage support equipment will now be removed from our Thickwood Hills application. The map on the bottom has been revised to show this change. We will apply for the voltage equipment in a future application instead. Page 2