A growing wave of rooftop PV projects is starting to look ominous to some utilities. Will lawmakers accept utilities’ warnings at face value—or will they suspect they’re crying wolf?
Stabilizing California's Demand
The real reasons behind the state’s energy savings.
the United States as a whole, which has seen household size decline over the same period: In 1980 the average U.S. household size was 2.75, a little higher than for California, whereas by 2006 this figure had fallen to 2.61. Given that larger households consume less electricity per person than do smaller households, these trends in household size may have contributed to the divergence between California and the United States in terms of residential electricity consumption. 16
• Housing Mix: California has become more highly urbanized with multi-family and attached housing accounting for 39 percent of total units in 2000, compared to an average of 31 percent in the rest of the United States. 17 In addition, the state has diverged from the rest of the United States in this respect: Since 1970 the proportion of total units accounted for by multi-family and attached housing has increased in California (from 33 percent to 39 percent) whereas in the rest of the country it has remained stable. Housing mix is important to understanding per capita consumption of electricity because multi-family and attached housing units generally use less energy than detached structures due to the insulating effects of multiple units.
• California’s Conservation Ethic: While we found that annual changes in savings from EE programs do not well predict changes in per capita consumption of electricity in California, the state’s focus on EE and conservation issues, along with the impact of price differentials, may have helped to create a “conservation ethic.” Data from the 2001 Residential Energy Consumption Survey (RECS) show that California households are more likely than those in the United States overall to report that they lower their winter temperature settings when no one is at home or during sleeping hours. For example, almost 60 percent of California households reported lowering their winter temperature settings when no one is at home or during sleeping hours, compared to less than 45 percent of all U.S. households. 18 While this does not contribute significantly to reduced electricity usage, it is in keeping with other data that support the idea of a California “conservation ethic.” For example, in California a smaller proportion of households report using electricity for heating water and cooking, and fewer households have electric dryers for clothing and a freezer separate from their refrigerator, than is the case nationally. 19 These findings likely reflect the state’s efforts with regard to EE and the promotion of energy conservation.
One of the factors that can influence a state’s consumption of energy is the type of industries that dominate the economy. The manufacturing sector is second only to transportation in terms of its share of total energy consumed nationally, and so can heavily influence overall consumption levels. Thus, the mix of industries in California is likely to be a contributing factor to the state’s relatively stable electricity consumption trend. Our analysis indicates that the manufacturing sector has contributed both to the relatively low levels of per capita consumption of electricity in California, and the divergence between trends in consumption in the state and