In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

Energy intensity is a measure of a nation's energy efficiency represented through energy use per unit of GDP (Gross Domestic Product).

Energy intensity is a measure of a nation's energy efficiency represented through energy use per unit of GDP (Gross Domestic Product).

School buildings represent 13% of commercial buildings energy use, or about 2.5% of total U.S. energy use (13% × 19%).

School buildings represent 13% of commercial buildings energy use, or about 2.5% of total U.S. energy use (13% × 19%).

School buildings represent 13% of commercial buildings energy use, or about 2.5% of total U.S. energy use (13% × 19%).

Most direct uses of primary energy are limited to generating heat and motion. Electricity, by contrast, is extremely versatile, with a wide range of complex applications. 

Most direct uses of primary energy are limited to generating heat and motion. Electricity, by contrast, is extremely versatile, with a wide range of complex applications. 

For decades, more than half of all residential energy use went  to space heating and cooling; in 1993, it accounted for nearly 60%. But EIA data show that by 2009, that share had dropped to 48%. And in the period 1993 to 2009, energy for appliances, electronics, and lighting rose from 24% to 35%, owing to the proliferation of appliances, as well as trends toward larger TVs and other devices.

Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

Carbon capture and storage will reduce energy efficiency of a coal plant, though it will decrease carbon emissions.

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot. 

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot. 

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot. 

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot.