1. Gen Maintenance w/ GridView DWG – Dec. 14, 2015 W ESTERN E LECTRICITY C OORDINATING C OUNCIL WECC System Adequacy Planning

2. Overview General concept – maintenance GridView Automatic maintenance scheduler Maintenance tuning 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

3. Maintenance - concepts Generator owners generally schedule at least one maintenance outage each year Maintenance schedules often considered proprietary Full year simulations – need to model generator availability 3 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

4. GridView Inputs for Maintenance Input Fields – Generator key – Gen Name – Duration – Schedule option – Start date – Start hour – End date – End hour – Derated cap 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

5. GV Automatic Maintenance Scheduler 5 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Thermal units Priority to low load periods One region at a time User can override

6. User Overrides Maintenance outages can be manually entered for individual units per users discretion Override candidates: – Nuclear units – Baseload units – Units with consistent outage periods (i.e. northwest thermal) Data available from public sources such as CEMS – Reason for inactive periods is not provided Regional entities could use proprietary data for their studies 6 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

7. Maintenance Tuning Have separate excel tool to tune maintenance schedules Various combinations of areas and generators reviewed NW_NWE shown 7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

8. 8 Contact Stan Holland Western Electricity Coordinating Council Senior Engineer stan@wecc.biz (801) 883-6858 Stan Holland Western Electricity Coordinating Council Senior Engineer stan@wecc.biz (801) 883-6858