Tracking energy efficiency performance in the United States
Energy productivity is a simple and widely measured metric. Productivity is the amount of service or useful work produced by a unit of energy. At the national level, energy productivity is gross domestic product (GDP) per unit of total primary energy consumed by the country. This broad metric may be affected by economic factors (such as the amount of manufacturing), climate, access to energy, and other conditions, as well as by efficiency. President Obama announced a goal, now supported by a Department of Energy (DOE) initiative, to double energy productivity over 2010 levels by 2030. The productivity is increasing but not fast enough to reach the goal. The small peak in 2012 was caused in part, by lower energy use due to the mild winter of that year. Note that energy productivity is the inverse of energy intensity, which is the energy consumed per unit of work done. We can track energy efficiency using either of these two metrics.
Energy use per person can vary widely with income level, geography, climate, and demographics. The graph shows energy use per capita in all the economic sectors in the United States in recent years. The decrease is mostly due to reduction in residential energy consumption in recent years.
Energy efficiency programs require upfront costs. Among a number of financing strategies, small charges levied on customer utility bills are the single largest source of funding for US energy efficiency programs. Administered by utilities or contracted to third parties, these energy efficiency programs involve customers in projects ranging from simple lighting replacements to whole-building retrofits. The graph shows annual customer-funded expenditures on US electricity and natural gas efficiency programs, which have been rising since a low in 1998.
Ratepayer-funded energy efficiency programs have saved billions of kilowatt-hours (kWh) for customers over the years. This indicator looks at electricity and natural gas savings from these efficiency programs, aggregated at the national level. The graph represents first-year energy savings from efficiency programs in each year as reported in our state scorecards. The SEE Action Network led by the Environmental Protection Agency (EPA) and DOE also provides resources to measure the benefits of energy efficiency.
One way to measure energy efficiency in residential buildings is to evaluate the total primary energy or source energy consumed per household. Primary energy includes the energy consumed directly in the buildings along with the losses incurred in the generation, transmission, and distribution of that energy. Delivered or site energy is the energy consumed by buildings on site, as reflected by a utility bill. About 50% of the energy used in residential buildings goes toward space heating, cooling, and water heating, which are influenced by climate and the size of the house, as well as energy efficiency. The graph shows primary and delivered energy per household in residential buildings.
Commercial buildings include office, retail, education, storage, services, food sales, religious worship, and healthcare buildings. While these range widely in their energy consumption, heating, lighting, and cooling take close to half of the energy consumed by all commercial buildings. We express energy efficiency in these buildings as energy used per unit of floor area (called energy use intensity or EUI). We can report EUI either for primary or delivered energy as discussed above for residential buildings.
Model energy codes establish the minimum energy standards for the design and construction of new buildings. Thus they facilitate and standardize building energy efficiency practices. From 1992 through 2012, these codes saved over $44 billion dollars in energy costs through the avoided use of 4 quads of energy. A quad is a quadrillion British thermal units (Btu). By way of comparison, 4 quads is more than all the energy consumed by Australia in 2013. Energy codes are set by states and sometimes local governments based on model codes from ASHRAE and the IECC, and are revised periodically. The graphs show an increasing number of US states with updated state-level building codes in 2010, 2012, 2013, and 2015 for residential and commercial buildings.
Appliances and equipment
Efficiency performance standards for appliances, equipment, and lighting have saved the United States a total of 55 quads of primary energy cumulatively since 1987. Savings in 2015 alone were almost 6 quads. In comparison, the United States consumed about 98 quads of primary energy in 2015. Performance standards ensure that all products sold in the country meet a minimum level of efficiency. The United States has set standards for more than 60 products that are expected to save consumers $1.9 trillion on their energy bills cumulatively by 2030. The graph shows annual savings from appliance standards in recent years.
The US industrial sector includes manufacturing, agriculture, mining, and construction. Energy intensity is the energy consumed per each dollar of goods produced by industry. A number of factors influence industrial energy intensity, including the type of manufacturing, industry structure, and energy efficiency. As the graph shows, US industrial energy intensity has been improving steadily. A lower number indicates that less energy is needed per dollar of goods produced.
Heat is a byproduct when a power plant burns fuel to produce electricity. This heat is typically released into the environment as waste. But a CHP facility (also called a cogeneration facility), captures the waste heat and uses it to heat or cool nearby buildings and industrial processes. Industries currently represent over 80% of all installed CHP capacity in the United States. Some hospitals, universities, and large office and housing complexes also use CHP to generate part of their electricity and heat on site.
Roughly a third of transportation energy in the United States is used to move goods rather than people. Although the sector is complex, the largest energy use is by long-haul tractor trucks, the large freight-hauling trucks with sleeper cabs. For simplicity we look at the average fuel economy required for those trucks. The first fuel economy standards for trucks and buses, adopted in 2011, took effect in 2014, as shown in the graph. The next increase in the standard will be in 2017. In August 2016 the U.S. Environmental Protection Agency and the Department of Transportation issued a second set of standards for trucks and buses through 2027. We estimate that under these standards long-haul tractor truck fuel economy will increase to 8.2 mpg by that year. The fuel efficiency of other freight modes (rail, air, ships) also is increasing, but more slowly.
Fuel economy measures how far cars and light trucks can travel on each gallon of fuel. Small gains in average miles per gallon lead to large savings nationally. Thanks to regulation and improved technology, the fuel economy of the average vehicle has been on the upswing since the mid-2000s after decades of stagnation. The fuel economy of diesel, gasoline, electric, and hybrid vehicles differs greatly. The graph shows the average fuel economy of all new passenger cars and light trucks sold in a given year. The fuel economy numbers differ from automaker standards compliance levels; they are adjusted to reflect real-world performance.
When we use it well, public transportation is generally more energy efficient than passenger cars. Large groups of people can ride together instead of everyone driving their own car to the same destination. The number of public transportation trips in the United States has been increasing by millions in recent years, generally because of changes in demographics and population as well as a better use of public transportation. The graph shows the number of recorded trips taken on public transportation vehicles per capita in the United States.
Other related metrics
Fuel efficiency and less driving have helped keep US oil consumption almost at the same level since 2000. At the same time, most of the oil reserves in the world exist outside the United States. Our domestic oil production has been rising, thus we currently import about 25% of the oil we consume, down from 49% in 2010. Energy efficiency can go a long way to help reduce dependence on imports by helping vehicles travel farther on each drop of oil.
We released billions of tons of greenhouse gases (GHG) into the atmosphere over the past hundred years, and we continue to release them. Over 77% of these emissions come from burning fossil fuels to produce energy for heating, cooling, lighting, transportation, industry, and other uses. Improving energy efficiency in buildings, vehicles, and industrial processes reduces emissions while providing the same or better products and services.
The EPA has a long history of addressing GHG emissions. In 2015, President Obama and the EPA announced the Clean Power Plan (CPP), which aims to reduce carbon pollution by setting the first-ever national carbon emission standards for power plants in all US states. Energy efficiency policies and technologies are proven, cost-effective strategies to help states meet their CPP targets by reducing energy demand.
Welcome to ACEEE’s national indicators of energy efficiency in the United States. This web page shows energy efficiency trends by sector. More information on ACEEE’s work in each sector can be found in the related links. The page will be updated on a yearly basis as new data become available. For questions or feedback on this page, please email us here.