Are Power Lines on the Way Out?
Alan Drew, Author of The American Lineman, Retired SVP of Research & Development at NLC
Since electric power was developed for productive use in the late 19th century, power has been delivered to consumers via overhead and underground conductors. The delivery system gradually evolved into today’s power grid, a maze of transmission and distribution lines spreading across the country. While Nikola Tesla is credited with his development of alternating current lines, he also had the vision of using electromagnetic waves to transmit electric power. To this end, he conducted extensive experiments at his Long Island, New York, laboratory.
The telegraph started the telecommunications industry in the 1840s. For decades, the telegraph and later telephone systems required physical conductors to send and receive messages. Around 1900, wireless telegraphy was developed by Guglielmo Marconi. This remarkable achievement opened the door for wireless technology in the telecommunications industry. In the 1930s, microwave technology was introduced for use in the military. More improvements in wireless transmission prompted the removal of telephone pole lines across the country.
Fiber optics were born in the early 1960s. In 1968, NASA used fiber optics in conjunction with television cameras sent to the moon. Cellular technology began in the 1970s and would be a game changer. Interestingly, while wireless technology has eliminated the need for lines with conductors, fiber optics require pole lines or underground facilities to place the cable. Most fiber-optic cable installations utilize existing wood pole lines that support electric power lines.
The Wireless Transmission of Electric Power
Wireless power transfer (WPT) is the transmission of electrical power without wires and is based on technologies using time-varying electric, magnetic, or electromagnetic fields. Most of the early efforts for wireless power transfer used microwave frequencies as used with Wi-Fi and Bluetooth. These efforts have been successful, and hold promises for future applications such as wireless device charging. However, larger volume power transfers over longer distances is beyond the capability of microwave frequency technology.
Laser-based power beaming has emerged as a promising technology for longer-distance WPT. This system uses a power supply that generates a laser beam of light energy through the air to a photovoltaic receiver, where the light energy is converted back to electricity.
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word “laser” is an acronym for “light amplification by stimulated emission of radiation.”
New Zealand’s second biggest utility, Powerco, is in the process of conducting a test of its system at a grid-connected commercial power station. The company hopes to bring energy to communities far from the grid or transmit power from remote renewable sources, like offshore wind farms. Several other research projects are experimenting with laser-based power beaming, which is the most promising technology for longer-distance electric power transmission.
The Future
There are numerous promising near-term applications for laser power beaming, such as keeping drones up in the air continuously. Radiated energy could power autonomous ground vehicles or provide a temporary power source on the battlefield or in a disaster area. It could even transmit power wirelessly from a solar or wind energy facility to a central grid.
Wireless power transfer technology can reduce the need for copper and aluminum used for electric conducting wire. Research indicates that metals used to make electric conductors will become extinct in the distant future as other materials are being explored.
The wireless power industry is expected to grow exponentially. Wireless power has a significant impact on almost all fields because it enables the Internet of Things to develop faster. Wireless in the low-voltage medium for various applications in buildings and other short-range situations will continue to evolve. Scientists predict that, someday, it may be possible to beam energy directly from the sun to each location where electric power is needed.
Conclusion
Let’s note the magnitude of power lines in the grid: The century-old U.S. electrical grid is the largest interconnected machine on Earth: 200,000 miles of high-voltage transmission lines and 5.5 million miles of local distribution lines, linking thousands of generating plants to factories, homes, and businesses. The role of the electrical grid in our economy has been so significant that it was named the “greatest engineering achievement of the last century” by The National Academy of Engineering.
In addition, with the emphasis of de-carbonizing the grid, thousands of miles of new lines are under construction or are in the planning stages. The number of transmission and distribution lines are increasing daily. Additionally, the use of electric power largely due to EV charging is projected to increase from 4,000 terawatt hours in 2020 to 7,000 terawatt hours by 2050.
So, we return to our original question: Are power lines on the way out? What is the future of linework? The answer should be centered around the fact that power lines and their components, such as structures, conductors, and transformers, will remain a vital component for the foreseeable future. Well-trained, qualified lineworkers are needed to continue constructing, maintaining, and operating the grid. There are no indications whatsoever that careers in the power and communications industries are in jeopardy. The dynamics of both industries offer more options for employment and career paths than ever before.
