Pine and fir trees are the preferred source for wooden electric poles, utility poles and telephone poles. Suitable species have tall, straight trunks and relatively small branches. These include lodge pole pine, Douglas fir, Jack pine, southern yellow pine and western red cedar. In the United States, wooden utility poles must be treated with preservative chemicals to standards set by the American Wood Protection Association.
Unlike wooden electric poles, which have a life span of 25 to 30 years, composite poles are impervious to rot, insects, fungi, woodpeckers and staples. They are light enough that even large ones can be carried by hand by three men, reducing installation costs, and are much less conductive than wood. The medium is flexible enough that composite poles are seen everywhere, from cottage lots to transformer stations.
Spun concrete has been used to make utility poles since the early 20th century. Installation costs are high, but these are the least conductive of all poles and arguably the best wearing. Spun concrete electric poles are available in everything from sophisticated period pieces suitable for an elegant driveway to transmission towers for national power grids.
All fiberglass electric poles have a composite element to them. Most composite poles have a fiberglass component. The identifying factor for a fiberglass versus a composite pole is that the outside coating of a fiberglass pole is pure fiberglass. Like composite, fiberglass is lightweight, long lasting, requires no upkeep and is adaptable to light or heavy-duty applications.
Buried metal poles are 100 percent grounded. Commonly used metals are aluminum, steel and ductile iron. Metal is used for everything from lampposts to transmission towers. The baked colors now available are highly UV resistant and compete favorably with composites and fiberglass in terms of durability.