1. Energy-Water-Climate Change Potential Scenario(s) Gary Graham—Chair, SPSG W ESTERN E LECTRICITY C OORDINATING C OUNCIL

2. Basic Plan For the Day Use all the SPSG work to date (meetings, workshop) to frame a scenario that will be drafted by Dec. 31. Agree on a scenario focus question Frame the scenario or scenarios Prioritize risks and the time frame Identify ways to mitigate risks Define risk early indicators Plan for drafting scenario 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

3. Efficient Decision Making Today A lot of work and information to process Straw man proposals to move the conversations forward SPSG members make all decisions – All participants have equal voice – All participants need to be heard All proposals and recommendations are amendable Potential causes of carbon pollution are out of scope for today’s meeting Finish each presentation then questions. 3 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

4. Potential Scenario Focus Question What are the most significant potential risks to reliability in the Western Interconnection that could result from changes to the climate and how can those risks be reduced and/or managed? Discussion of Question: Agree Change 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

5. Recommended Scenario: Straw Man: Highest temperature projection (8.5 o F by 2100) – wetter conditions in NW, – dryer in SW, – CO projections for the Rockies Greatest potential value and can be accomplished within our timeframe Extrapolate currently recognized risks into the future 5 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

6. EPA Temperature Projections From IPCC Emission Models 6 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Highest Emissions = +3 0 F in 2034

7. Recommended Scenario: Highest Temperatures Rationale: Creates the greatest risks to grid Preparations for greatest risks can be scaled down if indicators not met Don’t focus too much on actual temperature increases although 3 o F increase by 2034 is within range for highest emission scenario No substantial new policies, technological advances, or economic factors significantly reduce rate of CO2 emissions and temperature increases 7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

8. Vs. Lowest Temperatures Increases Lowest Temperature Increases: National and international policies, effective technological advances, and economic drivers lead to a stabilization of rate of carbon increases and temperature. With effective clean energy policies and technologies reducing rate of temperature increase, this potential scenario would be similar to original scenarios 2 and 4 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

9. Becomes complicated with geographical differencesBecomes complicated with geographical differences Alternative: Temp and Water Drivers 9 Water Availability & Reliability Extreme Temp Little Water Extreme Temp/ Much Water Moderate Temp Much Water Moderate Temp Little Water Very Dry Very Wet High Temperature Increase by 2100 (3 degrees F 2034) Moderate Temperature Increase (2 degrees F in 2034)

10. Other Options: All Four Carbon Emission Models: Using all 4 temp models is too complicated Very hard to fine tune risks to the grid among the four models Multiple Drivers: Many drivers affect climate change including policies and regulations, technological advances, fuel availability and prices, and changes in economies. These drivers are directly related to the emission models and thus are not independent of the temperature and water drivers Time is limited; it may be a better use of available time to focus on one selected scenario describing a plausible future. 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

11. Risk-timing Question 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Models start separation 2030 but temperatures are increasing now Transmission expansion takes a long time (10+ yrs.) Grid infrastructure lasts a long time Much uncertainty with risk calibration as you will see Recommendation: focus on addressing risks of 3 o F by 2034 that might not be fully seen until after that time frame

12. Scenario Choice Discussion Strawman: – Max Temp, Wet NW, Dry SW, Rockies Temp X Water Matrix – Four scenarios – Complex geographical All Four Carbon Emission Models: – Using all 4 temp models is too complicated – Very hard to fine tune risks to the grid among the four models Multiple Drivers: – Basically repeat of four 2013 scenarios – Not independent of temperature 12 W ESTERN E LECTRICITY C OORDINATING C OUNCIL