Sun: more than a star, an energy source
Various environmental studies conducted over the past few years point to the same trend: the aggravation of climate change. Following this awareness, the human being was forced to invest in renewable energy. Due to the impossibility of exploring all of them, the newspaper “Encontro” has tried to understand how solar PV energy works and its influence on global warming.
Solar panels very simply generate electric energy from sunlight, without movable mechanisms and without waste. Each of them consists of a set of photovoltaic cells, as explains Ricardo Aguiar, coordinator of the Energy Analysis and Networks Unit of the National Laboratory for Energy and Geology, that are able to “absorb energy of a photon that comes from solar radiation and turn it into energy for an electron which is then removed from the material to produce electricity.” In other words, they are able to transform solar radiation directly into electrical energy, through the so-called “photovoltaic effect” present in some metallic materials, with silicon being the most commonly used.
The photovoltaic effect occurs when a metal plate is exposed to an electromagnetic radiation of high frequency, for example, a beam of light that is sufficiently energetic to provoke electron ejection from the metal plate. This movement of electrons lies behind the electrical current that powers our appliances.
Nevertheless, before dealing with detailed explanations, we will zoom out, starting with Prehistorical times ... let's go back to the discovery of fire. Indeed, at this time, nobody spoke about fossil fuels and climate change and the art of lighting fires was appreciated. But the years passed and, to follow, hand in hand, the evolution of the human species, came global warming. How did it catch us? – You ask. We answer: mainly due to the burning fossil fuels.
Since the discovery of this energy source, the human being took it as if it were something inexhaustible, compromising not only environmental health but also the livelihood of future generations. Returning again to the 21st century and, as Ricardo Aguiar claims in statements to the newspaper “Encontro”, “existent climate changes cannot be reversed, that is to say, since most climate changes are due to greenhouse gas emissions during the burning of fossil fuels and this has happened on a large scale, you cannot counter their effects.” However, hope endures: Is it still possible to preserve the quality left in the blue planet, in a viable way? According to the expert, “alone, solar power does not [won´t be able to] but, within a range of renewable energy, may eventually help. Here the question of “being viable” is not only related to our knowledge of technology, but also to the sustainability of its use in economic, social and technical terms.” Casting a look at the nation, it is worth noting that Portugal is a privileged country with regards to the possibility of investing in solar energy: we are one of the European countries with more sunshine hours. And in fact, Portugal has made an effort to invest in solar energy: it is increasingly more common to hear about the installation of photovoltaic fields.
“There is still a long way to go technologically”
Still, a large number of photovoltaic panels is not enough. “It is also necessary that they have reasonable prices, it is necessary that their use does not have serious environmental impacts and they need to be reasonably efficient. These three strands are on the right track, but, there is still a long way to go technologically”, argues the researcher, who has a degree in geophysical sciences and a PhD in Physics-Meteorology. Despite positive trends, let us not forget, the crisis that shook Portugal a few years ago as an earthquake of infinite magnitude. If we want to maintain favorable levels of investment in solar energy, we are expected produce affordable solar panels but, surprisingly, the constraints are not of an economic nature. In fact, “there are more people, more families, more companies interested in installing photovoltaic solar energy at this point, than what is possible, on a technical level, to join our electric system”. Furthermore, according to Ricardo Aguiar, “the price of photovoltaic collectors is very dependent on their international price and, thus, the entry of large manufacturers, especially from China, Southeast Asia, has led to a price reduction, and even taking into account the growing capacity acquisition investment of households in Portugal, the prices are lower and lower.” In addition, the technical aspect is something to consider since replacing, at once, all power plants with renewable energy would lead to, as stated by the expert, “the breakdown in the electricity supply.”
In short, “no, there are no investment problems because the prices of photovoltaic solar energy are falling and, no, it's not an issue of trying to get lower costs that is leading, in fact, to an increase in supply and demand of photovoltaic solar energy”, as opposed to the predictions made during the economic crisis. “What is preventing, really, [the increased use of solar energy] is not a lack of demand or high prices, it is basically the lack of capital included in all this new power to produce photovoltaic electricity in our conventional network”, and therefore requiring a slow and gradual replacement of non-renewable energy by renewable energy.
Admittedly, despite the investments that have been made in this area, no country has yet managed to take full advantage of the benefits that this type of energy can offer. According to the expert, also coordinator and programmer of the SolTerm(performance analysis of solar systems) team, “there are some regions of the globe in which photovoltaic energy is already competing with other forms energy.” He adds that energy is more than just electricity, it “also includes thermal power and transport. In fact, photovoltaic energy has, as yet, a very limited application un terms of transport level.”
In conclusion, despite the recent growth of investment in renewable energy, there is still much work to be done. As ascertained by the newspaper “Encontro” and through the collaboration of Ricardo Aguiar, we understand that, although it is no longer possible to reverse climate change, it is possible to safeguard the future of the next generations. As a means to this end, renewable energies are presented, including solar photovoltaic power, which can be used not only to produce electricity, but also in several other areas already mentioned, really making a difference
The photovoltaic effect occurs when a metal plate is exposed to an electromagnetic radiation of high frequency, for example, a beam of light that is sufficiently energetic to provoke electron ejection from the metal plate. This movement of electrons lies behind the electrical current that powers our appliances.
Nevertheless, before dealing with detailed explanations, we will zoom out, starting with Prehistorical times ... let's go back to the discovery of fire. Indeed, at this time, nobody spoke about fossil fuels and climate change and the art of lighting fires was appreciated. But the years passed and, to follow, hand in hand, the evolution of the human species, came global warming. How did it catch us? – You ask. We answer: mainly due to the burning fossil fuels.
Since the discovery of this energy source, the human being took it as if it were something inexhaustible, compromising not only environmental health but also the livelihood of future generations. Returning again to the 21st century and, as Ricardo Aguiar claims in statements to the newspaper “Encontro”, “existent climate changes cannot be reversed, that is to say, since most climate changes are due to greenhouse gas emissions during the burning of fossil fuels and this has happened on a large scale, you cannot counter their effects.” However, hope endures: Is it still possible to preserve the quality left in the blue planet, in a viable way? According to the expert, “alone, solar power does not [won´t be able to] but, within a range of renewable energy, may eventually help. Here the question of “being viable” is not only related to our knowledge of technology, but also to the sustainability of its use in economic, social and technical terms.” Casting a look at the nation, it is worth noting that Portugal is a privileged country with regards to the possibility of investing in solar energy: we are one of the European countries with more sunshine hours. And in fact, Portugal has made an effort to invest in solar energy: it is increasingly more common to hear about the installation of photovoltaic fields.
“There is still a long way to go technologically”
Still, a large number of photovoltaic panels is not enough. “It is also necessary that they have reasonable prices, it is necessary that their use does not have serious environmental impacts and they need to be reasonably efficient. These three strands are on the right track, but, there is still a long way to go technologically”, argues the researcher, who has a degree in geophysical sciences and a PhD in Physics-Meteorology. Despite positive trends, let us not forget, the crisis that shook Portugal a few years ago as an earthquake of infinite magnitude. If we want to maintain favorable levels of investment in solar energy, we are expected produce affordable solar panels but, surprisingly, the constraints are not of an economic nature. In fact, “there are more people, more families, more companies interested in installing photovoltaic solar energy at this point, than what is possible, on a technical level, to join our electric system”. Furthermore, according to Ricardo Aguiar, “the price of photovoltaic collectors is very dependent on their international price and, thus, the entry of large manufacturers, especially from China, Southeast Asia, has led to a price reduction, and even taking into account the growing capacity acquisition investment of households in Portugal, the prices are lower and lower.” In addition, the technical aspect is something to consider since replacing, at once, all power plants with renewable energy would lead to, as stated by the expert, “the breakdown in the electricity supply.”
In short, “no, there are no investment problems because the prices of photovoltaic solar energy are falling and, no, it's not an issue of trying to get lower costs that is leading, in fact, to an increase in supply and demand of photovoltaic solar energy”, as opposed to the predictions made during the economic crisis. “What is preventing, really, [the increased use of solar energy] is not a lack of demand or high prices, it is basically the lack of capital included in all this new power to produce photovoltaic electricity in our conventional network”, and therefore requiring a slow and gradual replacement of non-renewable energy by renewable energy.
Admittedly, despite the investments that have been made in this area, no country has yet managed to take full advantage of the benefits that this type of energy can offer. According to the expert, also coordinator and programmer of the SolTerm(performance analysis of solar systems) team, “there are some regions of the globe in which photovoltaic energy is already competing with other forms energy.” He adds that energy is more than just electricity, it “also includes thermal power and transport. In fact, photovoltaic energy has, as yet, a very limited application un terms of transport level.”
In conclusion, despite the recent growth of investment in renewable energy, there is still much work to be done. As ascertained by the newspaper “Encontro” and through the collaboration of Ricardo Aguiar, we understand that, although it is no longer possible to reverse climate change, it is possible to safeguard the future of the next generations. As a means to this end, renewable energies are presented, including solar photovoltaic power, which can be used not only to produce electricity, but also in several other areas already mentioned, really making a difference
Work by: Inês Fernandes, Marta Loureiro, Cláudia Coelho, Mariana Pereira e Raquel Oliveira
11th Grade
Escola Secundária Francisco de Holanda (High School), Guimarães
Erratum:
No 1: Silicon, although it is often used in photovoltaic panels, does not rank as metal. It is a semiconductor element.
No 2: The burning of fossil fuels in significant quantities, does not occur since prehistoric times, but since the industrial revolution (about 250 years ago).
This work was carried out under the Flash Seminar held on the 5th and the 12th of May 2015 at Escola Secundária Francisco de Holanda (High School), in Guimarães. Students developed media content based on interviews with experts in various fields related to climate change and research on the subject.
11th Grade
Escola Secundária Francisco de Holanda (High School), Guimarães
Erratum:
No 1: Silicon, although it is often used in photovoltaic panels, does not rank as metal. It is a semiconductor element.
No 2: The burning of fossil fuels in significant quantities, does not occur since prehistoric times, but since the industrial revolution (about 250 years ago).
This work was carried out under the Flash Seminar held on the 5th and the 12th of May 2015 at Escola Secundária Francisco de Holanda (High School), in Guimarães. Students developed media content based on interviews with experts in various fields related to climate change and research on the subject.