Dictionary of Energy



The proportion of the incident solar light which is diffusely reflected from the atmosphere and surface of a planet back into space. The earth's albedo varies according to the patterns of vegetation and climate, and long-term variations in it may…

Air mass

Solar radiation is attenuated by the atmosphere before reaching the earth's surface, to an extent dependent on the angle of the sun above the horizon. This dependence is measured by the 'air mass', defined as the ratio of the distance…

Air conditioning

Domestic air conditioning is common in climates where high temperatures or high humidity occur, and the energy demands of air conditioning systems in summer can be comparable to those for heating in winter. In countries such as the USA and…

Air battery

A type of electric storage cell in which one electrode is activated by the oxygen in the air.


The science of air flow across solid structures, fundamental to the design of aircraft and essential for the optimization of automobiles, wind turbines and other devices. Proper attention to aerodynamics can make a 5-10 per cent difference to the energy…


See Atomic Energy Commission.