There are two electricity line transmission systems: overhead power lines and underground cables. Overhead power lines hang in the air and are supported by pylons, while underground cables are buried beneath the earth's surface.
Each power transmission system has its advantages and shortcomings. Here is an overview of how both systems perform on important several key factors.
Underground cables currently have a limited voltage capacity and cannot carry more than 66kv. In contrast, overhead power lines can handle more than 400kv, making them ideal for serving high-energy needs such as industrial applications.
Underground cables cost more to buy, install, and maintain compared to overhead power lines. Digging trenches and installing manholes and other special equipment for underground cables is more expensive than erecting pylons for overhead power lines. Additionally, underground cables must be coated by a thick coating because of the surrounding soil, which adds to their manufacturing costs. Overhead power lines use the surrounding air as insulation, reducing costs significantly.
Underground cables are less susceptible to outages compared to overhead power lines. The latter is secured underground, but overhead power lines are exposed to destructive elements such as extreme weather, birds, and critters.
However, underground cables are difficult to repair because of their rigid structure. It may take hours or days to locate and fix the problem. Overhead power lines are easier to assess and repair.
Underground cables have approximately half the durability and lifespan of overhead power lines. They last for about 35 years, while overhead power lines can last for up to 70 years. Additionally, underground cables have a limited application scope because of their limited voltage capacity. They are recommended for crowded cities where pylons are difficult to set up.
Overhead power lines often offer more benefits than underground cables. However, they may be more susceptible to damages from critters, but this is a manageable problem using Critter Guard products. We work with numerous utility and power distribution companies to protect their equipment and prevent further access. Our Line Guard and Pole Guard products can protect power lines and power poles from pesky critters including squirrels, snakes, rats, opossums, raccoons, monkeys, and birds. Feel free to contact us for more information.