Countries and ESIs surveyed ...................192
ESI companies listed .......................... 6,600
Generating companies........................ 2,050
Transmission companies ..................... 1,200
Distribution companies ....................... 5,300
Supply or trading companies ...................950

In compiling E EES SSI II 2 220 000 005 55 Ed 11,, ABS has built up a database of information about the electricity supply industry in every country over the last 13 years. In the early years this database reflected a traditionally integrated industry, much of it state-owned. ABS classified the utilities as generators, transmission companies or distributors. In many countries there were vertically integrated utilities performing all three functions, often with only one company serving an entire nation.

In 2005 the electricity supply industry is structured as a business rather than a public service supplier, with four separate functions; generation, transmission, distribution, supply, the last consisting of the marketing and sales of energy. In many countries competition has been introduced to generation and supply, while transmission and distribution are natural monopolies, since the electricity has to be delivered physically via the same wires. Privatisation has escalated. The result is a mix of systems throughout the world, ranging from traditional single vertically integrated utilities serving an entire country, to Electricity Supply Industries with all functions operating separately and in competition.

E EES SSI II 2 220 000 005 55 is a report designed to outline the ESI clearly and concisely in every country. One table summarises the characteristics of the industry, as in the example below for Spain. Similar information is provided for all major countries and advanced economies and in more abbreviated form for the smaller developing counties.