The mid to late 1880s saw the introduction of alternating current (AC) systems in Europe and the U.S. AC power had an advantage in that transformers, installed at power stations, could be used to raise the voltage from the generators, and transformers at local substations could reduce voltage to supply loads. Increasing the voltage reduced the current in the transmission and distribution lines and hence the size of conductors and distribution losses. This made it more economical to distribute power over long distances. Generators (such as hydroelectric sites) could be located far from the loads. AC and DC competed for a while, during a period called the War of Currents. The DC system was able to claim slightly greater safety, but this difference was not great enough to overwhelm the enormous technical and economic advantages of alternating current which eventually won out.
The business model behind the electric utility has changed over the years playing a vital role in shaping the electricity industry into what it is today; from generation, transmission, distribution, to the final local retailing. This has occurred prominently since the reform of the electricity supply industry in England and Wales in 1990. In some countries, wholesale electricity markets operate, with generators and retailers trading electricity in a similar manner to shares and currency. As deregulation continues further, utilities are driven to sell their assets as the energy market follows in line with the gas market in use of the futures and spot markets and other financial arrangements. Even globalization with foreign purchases are taking place. One such purchase was when the UK’s National Grid, the largest private electric utility in the world, bought New England’s electric system for $3.2 billion. Between 1995 and 1997, seven of the 12 Regional Electric Companies (RECs) in England and Wales were bought by U.S. energy companies. Domestically, local electric and gas firms have merged operations as they saw the advantages of joint affiliation, especially with the reduced cost of joint-metering. Technological advances will take place in the competitive wholesale electric markets, such examples already being utilized include fuel cells used in space flight; aeroderivative gas turbines used in jet aircraft; solar engineering and photovoltaic systems; off-shore wind farms; and the communication advances spawned by the digital world, particularly with microprocessing which aids in monitoring and dispatching.
Of course, choosing a new electricity supplier or natural gas supplier does not mean you are replacing your utility. Your utility will still deliver whatever energy supply you choose, safely and reliably. Since your utility company depends on where you live, you don't have to worry about choosing a utility company. In general, utilities are responsible for maintaining the energy infrastructure. If you experience a power outage or see a downed power line, call your utility company. These are listed in the Utility Companies column below.