Energy

Abstract

Energy is the capacity to cause changes in the world. It is stored in matter and force fields. The Sun produces energy by nuclear fusion. Solar irradiation, and reradiation and capture of the infrared by the greenhouse gases in the atmosphere, determine the climate on Earth and the environment for life. The combustion of coal, oil, and gas in heat engines, and non-fossil energy utilization, provide every citizen of the industrialized countries with energy services that are quantitatively equivalent to those of more than 40 hard-working men. They offer freedom from toil, comfort, mobility, information, and power. Transistors, running on electricity, work as powerful assistants to the human brain. A given energy quantity consists of a valuable part, called exergy, which can be converted into any form of physical work, and a useless part called anergy. Fossil and nuclear fuels, and solar radiation as well, are practically 100% exergy, and anergy is mostly heat at the temperature of the environment. All production processes in nature and industry decrease exergy and increase anergy. Energy consumption in this sense depletes the reserves of the easily accessible fossil fuels at a rate that, for oil, may soon culminate in peak Ooil. The potential of energy conservation and of non-fossil energy sources are assessed.