The US Energy Efficiency Resource Standard(EERS) is also known as Energy Efficiency Portfolio Standard(EEPS) or Energy Efficiency Commitment(EEC). The mechanism aims to produce, transport and use electricity and natural gases more effectively. EERS requires energy suppliers or distributors to reduce energy through customer energy efficiency programs based on a certain percentage and an increased percentage during a certain period of time or by annual and eventually implies the duty of reducing energy usage on consumers. This policy is similar in concept to Renewable Portfolio Standards (RPS). As energy efficiency facility can also reduce energy demand and greenhouse gases, EERS can be applied to a strategy for mitigating carbon pollution and climate change. In particular, many of the American programs carry out end-use energy efficiency programs to reduce a percentage of electricity and natural gases. As load growth across the country reaches approximately two percent each year, the reduced amount accounts for about fifty percent of load growth. Majority of the US states adopted Texas Public Utility Regulatory Act for energy efficiency. The Act provides provisions on energy efficiency targets, compliance of utility administrators, a way to recover energy efficiency costs, review and evaluation on program choices by the committee, energy efficiency for the state-run energy utilities, energy efficiency for electricity utilities, a project to prove energy efficiency for a solar power system, and writing a plan and a report on energy efficiency. Meanwhile, the Act provides provisions that a energy efficiency system under § 8. 2840 of CALIFORNIA PUBLIC UTILITIES CODE should quote Waste Heat and Carbon Emissions Reduction Act. The Act provides provisions on the definition in regard of the energy efficiency system, confirmation of energy efficiency at combined heat and power plants and of waste heat, electricity fee for combined heat and power plants established by the committee, air quality fee and purchase condition, the establishment of a program on a combined heat and power plant system to reduce greenhouse gases by using waste heat that comes from electricity utilities providing to end-users in relevant areas, cost effectiveness of combined heat and power plants, Pay-As-You-Save Pilot Program, a combined heat and power plant guideline, a duty to report on greenhouse gases reduction from combined heat and power plants. Thus, the Energy Efficiency Resource Standard can play a critical role in reducing greenhouse gases and at the same time driving energy efficiency business from which we can learn. And EERS can contribute to reducing energy significantly and drive an investment in enhancing energy efficiency, which suggests a lot to consider for legislative research on Korea’s energy demand.