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Trends in Electricity Consumption, Peak Demand, and Generating Capacity in California and the Western Grid, 1977-2000. Jolanka V. Fisher Timothy P. Duane University of California, Berkeley. Purpose of the Study.
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Trends in Electricity Consumption, Peak Demand, and Generating Capacity in California and the Western Grid, 1977-2000 Jolanka V. Fisher Timothy P. Duane University of California, Berkeley
Purpose of the Study • Debate about California crisis in 2000-2001 focused on internal supply-demand balance • Availability of imports is critical to the operation of the western (WSCC) grid • Temporal and spatial (co)variation in WSCC supply and demand are important • What is the temporal relationship between the regulatory regime and new capacity?
Data Collected and Analyzed • annual consumption, installed capacity, peak demand, gross state product, population, and utility vs. non-utility installed capacity for each state: 1977-1998 • summer/winter peak demand: 1995-2000 • PWP-085 addendum (December 2001) for California: all of the above for 1998-2000
Limitations of PWP-085 Study • coarse spatial and temporal variation in peak demand and consumption patterns • operating characteristics and fuel sources of installed capacity are not distinguished • only California data for 1998-2000 period • no data for critical 2001 period in crisis • only a descriptive study offering limited exploratory insights; no statistical analysis
Primary WSCC Findings • annual consumption grew 64% in 1977-1998 (from 350,000 GWh to 570,000 GWh) • non-coincidental summer peak demand grew by 10% (13,000 MW) in 1995-1999 • temperature-driven variation in demand • new utility capacity additions dropped off throughout the WSCC in 1988-1989 • the ratio of new installed capacity to new annual consumption declined about 10%
Primary California Findings • far fewer kwh per $ GSP and per capita • 1.7%/year growth vs. 3.5% (rest of WSCC) • decreasing share of summer peak demand • increasing share of winter peak demand • non-utility = half of new installed capacity • new capacity/new annual consumption ratio increased about 10% (still below WSCC’s) • consumption: 3.7% (1999) + 5.0% (2000)
Summary of peak demand changes • Between 1982 and 1998, the Southwest experienced phenomenal growth in peak demand. Its share of the peak rose by 50%. • In recent years, the Southwest has exhibited significant growth in peak summer demand, rising nearly 40% in just 5 years. • The Northwest also experienced large absolute increases in peak summer demand. • The Southwest had significant increases in peak winter demand, rising by over 30% in 5 years. • California exhibited a surprisingly large increase in peak winter demand, accounting for nearly half the increase (though its share of the peak is only a third).
Peak incidental demand by region, 1982-1998 Source: Western Systems Coordinating Council
Peak annual incidental demand by region (megawatts) Source: Western Systems Coordinating Council
Peak summer incidental demand by region (megawatts) Source: Western Systems Coordinating Council
Peak winter incidental demand by region (megawatts) Source: Western Systems Coordinating Council
Summary of capacity changes • Capacity additions dropped off for most states around 1989. • Looking only at utility capacity, California’s installed capacity per annual consumption ratio decreased over the last 2 decades. • The inclusion of QF capacity doubles the total capacity increase of California over the last 2 decades. • When QF capacity is included, California’s new installed capacity per new annual consumption ratio was greater than every state except Montana, Utah, and Wyoming.
New utility capacity by state, 1977-1997 Source: Department of Energy
New utility capacity during five-year periods by state, 1977-1998 Source: Department of Energy
Utility and QF capacity in California, 1977-1998 Sources: Department of Energy and California Energy Commission
New utility and QF capacity in California, 1977-1997 Sources: Department of Energy and California Energy Commission
Non-utility capacity by state, 1998 Sources: Department of Energy and California Energy Commission
New installed utility capacity per new annual consumption ratio by state, 1977-1998 Sources: Department of Energy and California Energy Commission
Supply < Demand = Crisis? • “California didn’t build any new power plants in the 1990s”: 5,058 MW added • California constrained demand growth to half the annual WSCC rate in 1977-1998, but its consumption jumped in 1998-2000 (decline in 2001 puts growth back on track) • Excess capacity throughout the WSCC was eaten up by increased demand everywhere • Temporal changes altered exchange patterns
Implications for the WSCC • managing demand growth is essential due to increasing summer peak demand in the Pacific Northwest and Desert Southwest • shifts in timing of sub-regional demand (winter/summer) reduce complementarity • operation of existing installed capacity and need for new capacity is now different than historic arrangement due to these shifts • transmission system plays a different role
Future Research Topics • cause of California’s increasing winter peak • demand-management options in other states • fuel sources, availability, and operating characteristics of existing and new capacity • transmission system constraints on trades given emerging new sub-regional balances • greater spatial and temporal resolution • using the above to model 2000-2001 system