Noé Vitos Álvarez
Turning on the light in our room, charging the pone battery, keeping food cold in the fridge or taking a hot shower, al lof these involve the need to transport electrical energy from the electrical substations to our homes. However, on the vast majority of occasions we are unaware of the effects and impacts these conveniences have.
On the other hand, the storage of this energy cannot take place in large quantities compared to other energy sources such as gas, oil or coal. It is therefore necessary to distribute the energy generated on the spot to the consumers, a distribution network being inevitable.
This distribution is achieved thanks to the electric towers, which serve as a support for the electric conductors to distribute the energy. These vary in size depending on the use and the voltage required, and are made of wood, concrete or mostly Steel.
This type of power line involves less expense than underground lines, since the cost of excavation and the passage of a line underground can be up to 4 times that of aerial transmission. However, these cost savings lead to a greater visual, environmental and social impact.
With regard to environmental impact, the construction of an overhead power line involves the segmentation and fragmentation of the territory, affecting the soils and the tree cover. The maintenance of these lines leads to the constant elimination of vegetation, causing an increase in fires in times of drought.
There are also important impacts on birds, every year more than 30,000 birds die from electrocution or collisions in Spain, the vast majority of which are threatened species, such as the golden and Bonelli’s eagles, eagle owls or Egyptian vultures. According to a study carried out by the animal biology department of the University of Barcelona, electrocution on power lines is 50% of the unnatural death causes of Bonelli’s eagle.
It is worth noting the excess of high voltage towers that can be found on the side of the mountain of Santa Cruz de Mieres, Asturias, belonging to the Soto – Ferreros electricity substation (Figure 1 and 2). Caused by the accumulation of towers of different voltages, built in different stages of the substation. The extension of this one meant the increase of towers around the previous ones, leading to the flooding of the mountain side of these metallic masses.
Electric lines generate electromagnetic fields due to the alternating electric current that circulates through the conductors. In turn, transformers are in charge of varying the voltage by means of magnetic induction. Thus, electricity undergoes a series of processes and transfers during its journey to the consumer.
From the generating plant, the high voltage arrives through the transmission lines to intermediate power stations where it begins to be reduced, being in this stop already used by the industries. Otherwise it continues its journey to other substations, where it is reduced again by transformers to reach small industries. Finally, the current arrives at the urban centers after its last transformation to be able to be transported within the city. However, very high voltage lines can be found buried within cities and in residential neighborhoods.
This is largely due to the expansion of cities, where previously there was a considerable distance from the city to locate high voltage towers, the growth has led to the construction of buildings adjacent to these areas of high electromagnetism.
There are numerous studies that attempt to interpret and investigate the potential health effects of electromagnetic fields generated by high voltage cables, which has been a very controversial issue for more than 20 years. Studies in Sweden, Germany and New Zealand have indicated a possible link to cancer, while similar studies in the UK, Norway, Canada and the USA have found no evidence of health risks.
The conclusion we reach is that despite their uncertain effect on people’s health, power towers have a huge environmental and visual impact on both people and wildlife. This should be taken into account when evaluating alternatives and solutions to avoid the construction of these metal giants.