Electricity comes from various sources and types of providers.

Дата: 2025-05-01; Просмотры: 15

Оценка:

0.00 из 5.00 — оценок

Скачиваний: 0

Скачать

The origin of the electricity that consumers purchase varies. Some electric utilities generate all the electricity they sell using just the power plants they own. Other utilities purchase electricity directly from other utilities, power marketers, and independent power producers or from a wholesale market organized by a regional transmission reliability organization.

The retail structure of the electricity industry varies from region to region. The company selling you power may be a not-for-profit municipal electric utility; an electric cooperative owned by its members; a private, for-profit electric utility owned by stockholders (often called an investor-owned utility); or in some states, you may purchase electricity through a power marketer. A few federally owned power authorities—including the Bonneville Power Administration and the Tennessee Valley Authority, among others—also generate, buy, sell, and distribute power. Local electric utilities operate the distribution system that connects consumers with the grid regardless of the source of the electricity.

The process of delivering electricity.

Power plants generate electricity that is delivered to customers through transmission and distribution power lines. High-voltage transmission lines, such as those that hang between tall metal towers, carry electricity over long distances to meet customer needs. Higher voltage electricity is more efficient and less expensive for long-distance electricity transmission. Lower voltage electricity is safer for use in homes and businesses. Transformers at substations increase (step up) or reduce (step down) voltages to adjust to the different stages of the journey from the power plant on long-distance transmission lines to distribution lines that carry electricity to homes and businesses.

Evolution of the electric power grid.

At the beginning of the 20th century, more than 4,000 individual electric utilities operated in isolation from each other. As the demand for electricity grew, especially after World War II, utilities began to connect their transmission systems. These connections allowed utilities to share the economic benefits of building large and often jointly-owned electric generating units to serve their combined electricity demand at the lowest possible cost. Interconnection also reduced the amount of extra generating capacity that each utility had to hold to ensure reliable service during times of peak demand. Over time, three large, interconnected systems evolved in the United States.

3. Соедините слова в левой и правой колонке так, чтобы получились выражения, которые есть в тексте. Запишите полученные словосочетания в тетрадь с переводом.

Например: Electricity is delivered … through a complex network.

4. Прочитать текст, понять его содержание.