As of July 2017, thirty states and the District of Columbia have adopted energy efficiency policies—either mandated requirements, voluntary goals, or pilot programs—designed to lower the growth of electricity consumption by using electricity more efficiently. Seven of these states have either created new or updated existing energy efficiency standards within the past year.

Since Texas became the first state with an energy efficiency resource standard (EERS) in 1999, 24 states have adopted an EERS. Four states have set voluntary goals, and two states established energy efficiency pilot programs. An EERS uses either financial incentives or non-performance penalties to encourage energy efficiency and reduce electricity sales. Typically, EERS targets increase over time.

Efficiency targets may be set as reductions from retail electricity sales in a base year or the average of prior years, as a cumulative reduction over a compliance period, or as a percent of a long-term forecasted consumption amount. An EERS may specify reductions for energy use, peak electricity demand, or both. Some newer policies include traditional customer-incentive programs such as lighting or cooling equipment rebates as well as utility-sponsored measures that make the electricity distribution system more efficient.

Read more. (U.S. Energy Information Administration)