From 2011 to 2013, the Sacramento Municipal Utility District in California automatically enrolled 174,000 households in a variable-pricing plan. The aim was to cut the expensive consumption in peak hours and days. More than 95 percent of these customers stayed in the new pricing plan, while in comparison, only 20 percent of people who were not enrolled in a variable-pricing plan joined one.
Once they joined the new plan, customers got to know it and began to use it slowly, but firmly: they cut their peak consumption by 7% during the first year, and by 12% on the following one. In comparison, people who opted in to the plans voluntarily were presumably savvier and more conscious consumers, as they reduced their consumption by respectively 25 and 23 % during the first two years of the experiment.
The initiative was such a success that the Sacramento Municipal Utility District is rolling out automatic enrollment to all its electricity customers starting in late 2018, with the goal of converting all of them by the end of 2019.