This is how energy is produced thanks to the sun
Solar panels use a very simple technology for their operation. Its components are few and the sun makes them work at full capacity. There are cities that have even prepared their own roof map and its characteristics to make it easier for its inhabitants to install solar panels. All with the aim of promoting sustainability.
This is how energy is produced thanks to the sun
Self-consumption of photovoltaic energy is acquiring such a leading role that there are already cities in Spain such as Vitoria (Álava) or municipalities such as Alpedrete (Madrid) that have maps that indicate what each of their buildings has to generate energy through solar panels depending on the orientation of their roofs.
But of course, it does not only happen in Spain, nor is this energy only used for self-consumption. A Belgian tunnel incorporates some 16,000 solar panels on its roof with which all the trains that go from Antwerp to the Netherlands are supplied. In total, three kilometers of plates that allow the trains to work thanks to sunlight.
Examples of successful experiences with solar energy are becoming more and more numerous.
Spain, a country with many hours of sunshine
The reason for this success is none other than the ease of starting up a solar installation, its low cost due to its rapid amortization and the number of hours of sunshine per year in Spain. For example, Madrid is the sunniest European capital, with almost 3,000 hours a year.
Soon even the windows in our homes and offices will function as transparent solar panels. A team of researchers in chemical engineering and material sciences from Michigan State University, USA, wants to turn any piece of flat glass into a solar panel: windows, car windshields, mobile screens…
For that moment to come, we will still have to wait, but solar energy is not slowing down, nor is its market. The annual market growth rate will be 24.2% until 2022, according to a report by the International Renewable Energy Agency.
Thermal and photovoltaic installations: this is how they work
The really interesting thing about all this is to see how something with such a simple operation has such great productivity. Solar installations can be thermal and photovoltaic.
The first have a relatively simple operation. The basic elements involved in an installation of this type are: solar panels that capture solar radiation and heat the fluid that circulates through them, a hydraulic circuit to transport the water heated in the collectors, copper pipes for the primary hydraulic circuit of solar thermal energy and a heat exchanger.
Thermal solar energy is not consumed in its entirety instantly, since it depends on the existing demand at any given time, so in order not to waste it, it is necessary to accumulate it. For this reason, we need a system for the accumulation of hot water for consumption so that it can be supplied as it is demanded.
This is achieved with accumulators, which are nothing more than tanks with sufficient capacity and insulation to avoid, as far as possible, energy losses.
As the time comes when window panes become common photovoltaic power sources, we have solar panels. “The basic unit of energy transformation is the solar cell, which is usually 10 by 10 centimeters in size. A panel unites several of these cells on a plate, which are then covered with plastic to protect them”, explains photovoltaic energy researcher Íñigo Ramírez González.
Silicon in wafer form
The cell, made of silicon, works like a battery that is encapsulated in these plastics to protect it from inclement weather or dust in suspension. They are grouped in series to gain voltage and intensity of electrical current (a cell generates about 4 watts, while a module of about 60 cells, which is usually the standard, generates 250).
The silicon that makes up the cell is cut into a wafer shape. The chemical process to convert one of these wafers into cells is probably the most complicated part of the entire installation and of the operation itself. To measure whether a cell is good or bad, its voltage is measured one by one and they are placed in a balanced manner on the panels so that some do not have more voltage than others.
The upper layers of the silicon cells are loaded with electrons that, when they receive the energy of photons from sunlight, recombine and become current. The current that these cells generate is continuous, so an inverter is needed to convert it to alternating current, which is what we use.
It is necessary to have a battery to store energy if we want to use it at night, although this accumulation system is not the most common, especially in homes.
An installation of solar panels for four people would cost approximately 15,000 euros, although the final price depends on many factors.
