Why don't we make all the wires underground?

Moving electrical wires underground can help avoid hazards during a storm. However, the ducted underground network also has its own problems.

The first message to be transmitted through Samuel Morse's telegraph line was the question, "What hath God wrought?", Sent from Washington, DC to Baltimore, Maryland through a suspension system above houses and columns. the wood. The suspended telegraph wire was soon replaced by the telephone line of Alexander Graham Bell and the ever-expanding electrical network that connects the community. However they are not a popular option. At first, people complained about telephone poles, because they said it was ugly and unreasonable. Today, people say they carry a lot of risks.

Every year, storms, blizzards and a host of other weather events destroy utility works on the ground. Heavy snow and ice can break the cord. More commonly, intense winds overturn poles, or uproot nearby trees, pulling strings.

The cost of the blackout is huge . Many analyzes show that even an hour's blackout can cost commercial and industrial facilities tens of thousands of dollars, and blackouts often last more than a day. In specific industries such as museums, power outages can also affect the environment for preserving valuable antiques. And as we have seen after the aftermath of Hurricane Maria in Puerto Rico, damaged grid lines can take human lives.

That is why many people argue about "underground" , the process of moving from a high position to a tunnel protected underground. Proponents argue that doing so will help ensure grid safety even in stormy places like southern Florida. But Ted Kury, director of energy research at the University of Florida's Center for Public Research, says it doesn't need to be rushed. Ducting can reduce storm-related power outages in some places. But these tunnels carry their own problems and cost issues .

A photo from the National Oceanic and Atmospheric Archives (USA) shows the impact of ice and snow on telephone poles.

An expensive process is not guaranteed

There are two methods used to remove power poles and bring them underground.The cheapest method is called open digging, which is how companies dig deep into the ground, put wires in and then fill trenches afterwards. In this way, people 's traffic and transportation will be affected (even temporarily).

Many cities choose this method instead of directional drilling . Similar to an old oil drilling technique, directional drilling is a less invasive but more expensive option. From a fixed point, a pipeline is put underground for miles without affecting street activities.

For both of these, there must still be certain changes to the front line that takes them underground, most importantly the heat dissipation problem . In essence, electrical wires are very hot because they are the means of electric transport. Outdoors, this heat can dissipate, but when deep in the ground it is impossible. That's why underground wires are covered with plastic and surrounded with a layer of oil to keep things from overheating.

That sounds simple, anyone with an excavator can do it! Depending on the density of the local population and the topography, ducting can cost billions of dollars . According to Kury, many localities have outlined the costs for undergrounding and come to the conclusion that it is not "worth the money". For example, in North Carolina, the process of undergroundization lasted about 25 years and led to a 125% increase in electricity prices. Most lines are still in suspension form. Even Washington, DC, with a partial ducting decision, is expected to cost $ 1 billion.

That is not the only cost. Repairing underground systems is often more expensive than repairing overhead systems."When there was a power outage, there were two obstacles to fixing the line , " Kury said . "One, identify the error, and then the repair line" . While smart grid technology makes it easier to identify faults and accurately indicate where a system is disrupted, repairing underground systems often requires digging, which is more difficult. if the land freezes in the blizzard.

Finally , no system can be protected in every situation. During Hurricane Sandy, which struck the northeast of the United States in 2012, underground electrical equipment flooded and electrical poles on the ground collapsed. "It is almost impossible to protect the grid from damage , " Kury said.

Other advances in grid protection

Locations that do not want to invest in large underground projects may have other options. In recent years, many cities have replaced old wooden columns with durable metal frames. The ligaments can help anchor the columns to the ground. At the same time, Kury said that the management of vegetation is very important. Pruning, watering and helping plants fight pests can keep them healthier and more resistant to storms. At the same time, quickly remove weak trees to avoid the risk of them being able to destroy nearby power lines when high winds.

Many companies have also resorted to using drones. Commercial drones can help reduce the response time for customer calls. In some places, data from drones is used to share the latest information with technicians and customers about everything, from the height of the lines to the function of the internal sewer. Town. And in a difficult situation, unmanned aircraft can support aerial reconnaissance in stormy locations that are inaccessible.

The smart grid has also helped overcome the problems that arise. In recent storms, Kury said, Florida's electricity suppliers have chosen to close substations at risk of flooding and reroute energy. It is hoped that such proactive decisions will allow the grid to be restored more quickly and reduce the likelihood of causing danger across the system.

In summary "There is no solution suitable for all places". Each city must make decisions that are right for its residents, and accept the fact that no system can work perfectly when dealing with natural phenomena.