# Presentation: 754806

## Climate Science Needs for Long-term Power Sector Investment Decisions

- Victor Niemeyer
- EPRI
- _[niemeyer@epri.com](mailto:niemeyer@epri.com)__, 650-855-2744 _

## Power System Planners See a High-level of Uncertainty for Climate Change

- Temperature uncertainty
- Time path of annual average temperature
- Seasonal distribution of temperature changes
- Distribution of changes by day types
- Change in severity of extreme days
- Change in number of extreme days
- Change in number or intensity of extreme episodes
- Regional distribution of changes
- Water for hydro generation and availability for cooling
- Change in frequency and intensity of storms
- Sea-level rise

## EPRI/CRIEPI Study Examined Potential Effects of Climate on Electric Utilities

## Impact of Climate Change on Demand Dominated All Other Pathways

**Impact of Climate Change on Demand Dominated All Other Pathways**

## Temperature Change Scenarios Result in Large Effects on Loads, Generation and Total Costs

## Utility Planning Priorities

- Avoiding poor reliability due to inadequate generation or transmission
- Avoid launching uneconomic generation due to
- Unanticipated high construction cost
- Poor fit with transmission system
- Fuel/emission price changes
- Poor fit for load shape

## Loads Highly Variable by Hour, Day and Season

## Load Uncertainty a Key Challenge for Generation Planning

- The standard deviation of forecasted loads jumps in first year due to weather uncertainty and then rises over time due to uncertainty in economic growth

## Generation Planning Practice (integrated regulated utilities)

- Assess load growth rate
- Observe loads and weather
- Create weather-adjusted load history
- Forecast weather-adjusted load growth rate
- System level and/or by “load pocket”
- Develop plan for immediate needs
- Review plan with stakeholders and execute
**Challenge – separating climate change signal from noise**

## Finding Climate Change Signals in the Noise

- What changes planners care about
- Season (summer/winter/shoulder)?
- Time of day (day/night, min/max temp changes)?
- Where (micro regions/service territory/broad regions)?
- How soon, how much?
- Possible changes highly uncertain
- High level of underlying variability
- How can planners “know” of changes requiring response?

## Planning Reserve Margins Help Avoid Reliability Risk Due to Uncertainty

**Notes:**
Changed HEPCO and SOCO numbers, table now matches Table 7-8, p. 7-13 of the final report

## Utilities Use a Mix of Peaking and Baseload Generation to Minimize Costs

- Peaking units – gas CTs and CCs
- Low fixed costs (capital + FO&M)
- Higher operating costs (fuel + emissions + O&M)
- 1-3 year lead times
- Most economic for loads < 1,500 hours/year
- Baseload units – coal, nuclear
- High fixed costs
- Lower operating costs
- 4-10 year lead times
- Most economic for loads > 1,500 hours/year

## Least-cost Generation Mix Depends on Load Shape and Generation Economics

- Baseload lower cost

- Peaking lower cost

- 1,500 hours/yr “boundary” between peaking and baseload generation

## If Temperature Increases Concentrated in Summer Season Change Least-cost Mix 

- Fuel price uncertainty has much larger effect on mix than climate change uncertainty

## Insights

- Lead times for new generation short compared to potential temperature changes that occur gradually
- Growing power system has many opportunities to adapt to changing load patterns due to climate change
- However, identifying climate change-driven shifts in load patterns extremely difficult
- Information tracking local climate variation over time may help planners adapt to changes more effectively