In electrical grids, they are generally used to carry high-voltage transmission lines that transport bulk electric power from generating stations to electrical substations; utility poles are
used to support lower-voltage subtransmission and distribution lines that transport power from substations to electric customers. They come in a wide variety of shapes and sizes.
Typical height ranges from 15 to 55 m 49 to 180 ft,[1] though the tallest are the 380 m 1,247 ft towers of a 2,656 m 8,714 ft span between the islands Jintang and Cezi.
The longest span of any hydroelectric crossing ever built belongs to the powerline crossing of Ameralik fjord with a length of 5,376 m 17,638 ft. In addition to steel, other materials may be used,
including concrete and wood.