Overview

Energy is an essential element for modern society for comfortable living in well-lighted, heated, and air-conditioned spaces equipped with modern appliances. The goal of an energy system is to transform primary sources into various forms of fuels and energy carriers to supply energy needs of the society. The chapter discusses the share of various sources supplied to consumers and the impacts of site energy consumption or production on natural resources and the environment. Primary sources are processed to produce fuels and energy carriers. Secondary energy sources are commodities obtained by converting primary sources into more convenient forms to supply consumers. Processed fuels, electricity, and hydrogen are the most common secondary energy sources. Energy sources are strategic commodities controlled by the essential rules of economics. Energy indicators must be interpreted carefully considering macroeconomic indicators and technical characteristics that affect the end use of energy.