1 Electricity Use in California: Past Trends and Present Usage Patterns Rich Brown May 2002

2 Overview n Background n Was CA’s demand growth unprecedented? n Was CA’s demand growth unforeseen? n How many houses can 1 MW supply? n Which end uses contribute most to peak? n How do we know all this? n Looking forward

3 Background n Origins in EET demand-response white paper n Mainly based on CEC and FERC data n Electricity use values cited here exclude T&D losses, but include loads served by self- generation n Further data in Brown & Koomey (2002), forthcoming in Energy Policy

4 Was demand growth unprecedented or unforeseen?

5 CA Electricity Consumption

6 CA Peak Load

7 Was Demand Growth Unprecedented? n Growth slowed in the 90s n Growth rates in 90s were lower than any time except Depression and early 70s n Absolute growth in consumption in 80s was similar to 50s and 60s

8 Was Demand Growth Unforeseen? n As early as 1988, CEC overpredicted 2000 demand n Early 90s recession led to lower growth n Root cause of power crisis was little new generation added in Western U.S. n How accurate was the CEC forecast?

Electricity Consumption Growth

Electricity Peak Load Growth Peak load in Ag sector declined by 300 MW.

11 How Many Houses Can 1 MW Supply? n Conventional wisdom says 1000 houses n On peak: 600 houses n On average: 1,200 houses n Rule of thumb can be misleading n CA ISO now uses 750 houses n Only relevant for dispatchable resources

12 CA Households per MW of Capacity Source: CEC; 1999 data

13 Which End Uses Contribute Most to Peak?

CA Building Sector Consumption and Peak Demand - Top 10 Highest-Peak End Uses

15 California 1999 Summer Peak-day Load

Residential Summer Peak-day Load

Summer Peak-day Commercial Building Load

Summer Peak-day Industry & Other Load

19

20 How have end use shares changed over time?

21 CA Residential Electricity Consumption (and Annual Growth Rate)

22 A Note About the Data n Empirical data sources –Monthly consumption at customers’ meters –Hourly loads at various points in transmission grid –Hourly use and annual consumption by end use for small samples of customers –Equipment ownership and usage n Aggregate use derived analytically n Key uncertainties: end use load shapes, diversity factors, building/equipment operation

23 Looking Forward n Improve baseline estimates –Update/improve load shape data –Incorporate data from interval meters n Reduce peak & make it more price-responsive –Which end uses/building components to target? n Big challenge: population and economic growth swamp efficiency improvements

24 For further information see:

25 Backup Slides

26 Electricity Supply Profile for Typical Hot Summer Day Source: CEC

27

28 CEC Power Plant Permit Filings 11,350 MW