Rosenfeld Curve

Named after the pioneering physicist Arthur H. Rosenfeld (CEC Commissioner, 2000-2010), the Rosenfeld Curve describes the trend of California’s per-capita electricity consumption staying relatively flat since the 1970s, while the rest of the U.S. experienced an increase in per-capita electricity consumption. California set the nation’s first efficiency standards for both appliances and buildings, spurring technological advances that led to significant energy savings for the state. The Rosenfeld Curve can be attributed to these innovations in energy efficiency, as well as to differences in industrial sector trends, climate conditions, and demographics.

The Rosenfeld Curve dashboard displays the historical (1970 – 2024) electricity, natural gas, and combined total consumption per capita of California, and compares that with the per capita consumption of the rest of the U.S. by year. Energy data featured in the dashboard are derived from U.S. Energy Information Administration (EIA) Data, and population data is from the U.S. Census Bureau. In the dashboard, all three comparisons are showcased and can be viewed by selecting the corresponding navigational tab. Users can select and apply filters and see the corresponding filtered data in the Rosenfeld Curve comparison. For the Electricity and Natural Gas Highlights, the highlights are noted by the corresponding arrow in the dashboards.

Dashboard is best viewed from a computer. Visit Tableau for the full page layout of dashboard or download data.

British thermal unit (Btu) is a measure of the heat content of fuels or energy sources. One Btu is the quantity of heat required to raise the temperature of one pound of liquid water by 1° Fahrenheit (F) at the temperature that water has its greatest density (approximately 39° F).

MM Btu means one million British thermal units. A therm is a unit of heat energy equal to approximately 100 cu ft of gas or one hundred thousand (100,000) British thermal units.

California’s appliance and building efficiency standards, such as those set by Title 20 and Title 24, have spurred innovation and drastically reduced California's energy consumption. Consumption patterns are not only driven by efficiency regulations but are very dynamic and influenced by a multitude of factors which include technology, weather, industry, etc.

To show this dynamic nature, the Rosenfeld Curve dashboard is formatted in multiple views that can be accessed by the navigation tabs displayed at the top of the dashboard. This format allows the user to expand from the traditional Rosenfeld Curve by focusing on one facet of consumption highlights. These include electricity and natural gas highlights over the years. When the Electricity Highlights navigation tab is selected, the Rosenfeld Curve electricity highlights over the years dashboard is displayed. When the Natural Gas highlights navigation tab is selected, the Rosenfeld Curve natural gas highlights over the years dashboard is displayed. Users can return to the Rosenfeld Curve dashboard by selecting its tab or using the navigation arrow to move between dashboards.

The Rosenfeld Effect is not a scientific law, but rather an observed trend: Since 1973, California’s per capita electricity consumption has remained significantly low, while usage across the U.S. has steadily increased. Energy analysts refer to this pattern of stabilized demand as the "Rosenfeld Curve" or "Rosenfeld Effect."

The main insight from the Rosenfeld Curve is that over the past decade, electricity consumption in California has declined by approximately 10%, compared to a modest 2% decrease across the U.S. During the same period, natural gas consumption in California dropped by about 4.6%, while it rose by around 2% nationwide. Overall, California's total energy consumption has fallen by roughly 7% in the last 10 years, whereas total energy use in the U.S. has remained relatively stable. Over the past decade, national per capita energy consumption has demonstrated an increasing trend, whereas California’s per capita energy consumption has been decreasing, leading to California’s per capita energy consumption being approximately 50% of the national average in recent years.

Data as of: December 31, 2024

Dashboard last updated: August 10, 2026

Data Collection Information

  • Electricity consumption data derived from EIA Data, Series Name: ESTXB, Electricity total end-use consumption (electricity sales to ultimate customers).
  • Natural Gas consumption data are derived from EIA Data, Series Name: NGTXB, Natural Gas total end-use consumption (including gaseous fuels).
  • EIA total end-use consumption estimates are the sum of the consumption estimates for the residential, commercial, industrial, and transportation sectors.
  • Population data is from the U.S. Census Bureau.

Related Links

Citing
Please cite use of these data and images. California Energy Commission [Year]. California Energy Commission [Rosenfeld Curve Dashboard] Data last updated [insert date last updated]. Retrieved [insert date retrieved] from [Dashboard URL]

Contact

Energy Assessments Division, Data Collection and Analysis Unit
QFERDemand@energy.ca.gov