Although energy efficiency was already heavily emphasized in the 1970s as a key strategy for energy security, more recently it has also been recognized as one of the most cost-effective strategies for reducing environmentally harmful emissions. Energy...

Improving productivity is one of the central concerns of businesses. In buildings, energy-efficient technologies and design strategies can improve labor productivity (output of goods and services per hour worked) far in excess of the improvement in...

The large increases in energy prices during the 1970s encouraged extensive interest in reducing energy use and in using energy resources efficiently. The common belief resulting from the energy crisis was that private markets would not provide an...

The utilization of energy for human purposes is a defining characteristic of industrial society. The conversion of energy from one form to another and the efficient production of mechanical work for heat energy has been studied and improved for...

Energy efficiency is a ratio of energy input to useful energy output, often expressed as a percentage. It measures how much energy of one kind is converted into usable energy of another kind. Incandescent light bulbs convert just 5 percent of the...

Energy efficiency is a measure of how much of the input energy is useful as output energy. An automobile, for example, typically has a low efficiency, around 30%, as much of the consumed fuel is converted to heat instead of power in the driveshaft. A...

In physics and engineering, including mechanical and electrical engineering, energy efficiency is a dimensionless number, with a value between 0 and 1 or, when multiplied by 100, is given as a percentage. The energy efficiency of a process, denoted by...