Description: American Clean Energy and Security Act of 2009 has created a cap-and-trade mechanism, a market-based incentive to reduce carbon emissions. It mandated a combined renewable electricity and energy efficiency standard (RES/EERS) requiring that 20% of electricity sales by 2020 be met by renewable energy and energy efficiency. The bill also included a number of key policies designed to increase savings from energy efficiency, including improved building codes, appliance and lighting. Although, the American Council for an Energy-Efficient Economy (ACEEE) has estimated that the bill could have delivered net energy bill savings of $350 billion by 2030, while also generating more than 424,000 additional jobs by 2030, the bill has not been accepted as a law. In 2013, the Department of Energy (DOE) published a series of protocols for estimating savings from energy efficiency programmes, titled Methods for Determining Energy Efficiency Savings for Specific Measures. The protocols, developed in collaboration with leading technical experts, provide a straightforward method for evaluating gross energy savings for a number of the most common residential and commercial measures and programmes offered by utility ratepayer-funded energy efficiency programmes in the United States. On the other hand, USA has substantially improved its fuel efficiency standards and has set goals for all class of vehicles for 2025.