Solar photovoltaic energy or PV solar energy directly converts sunlight into electricity, using a technology based on the photovoltaic effect.
When radiation from the sun hits one of the faces of a photoelectric cell (many of which make up a solar panel), it produces an electric voltage differential between both faces that makes the electrons flow between one to the other, generating an electric current.
There are three types of solar panels:
When photovoltaic technology first began, it was used to provide electricity to satellites. According to APPA (the Spanish Association of Renewable Energy Producers), development of photovoltaic panels sped up in the 1950s and has now become an alternative to the use of fossil fuels.
Electricity generated by solar photovoltaic panels is inexhaustible and does not pollute, and thus contributes to sustainable development as well as favoring local employment.
Solar photovoltaic energy doesn't emit greenhouse gases that cause global warming in energy generation processes, making them the cleanest, most viable solution to prevent environmental degradation.
Compared to conventional energy sources such as coal, gas, oil and nuclear - reserves of which are finite - clean energies are just as available as the sun from which they originate and adapt to natural cycles, hence their name “renewables”. This makes them an essential element in a sustainable energy system that allows development today without risking that of future generations
Photovoltaic energy does not emit toxic substances or contaminants into the air, which can be very damaging to the environment and to human beings. Toxic substances can acidify land and water ecosystems, and corrode buildings. Air contaminants can trigger heart disease, cancer and respiratory diseases like asthma.
Photovoltaic energy does not generate waste or contaminate water—an extremely important factor given the scarcity of water. Unlike fossil fuels and nuclear power plants, wind energy has one of the lowest water-consumption footprints, which makes it a key for conserving hydrological resources.
Nowadays renewables, specifically wind and photovoltaic, are cheaper than conventional energies in much of the world.
The main renewable technologies – such as wind and solar photovoltaic – are drastically reducing their costs, such that they are fully competitive with conventional sources in a growing number of locations. Economies of scale and innovation are already resulting in renewable energies becoming the most sustainable solution, not only environmentally but also economically, for powering the world.
In addition, solar photovoltaic energy is a “native” energy, because it is available practically everywhere on the plant, which contributes to reducing energy imports and to creating wealth and local employment.
For these reasons, producing electricity through solar photovoltaic energy and its efficient use contributes to sustainable development.
En este vídeo didáctico podemos ver qué es la energía solar fotovoltaica y los diferentes tipos de paneles solares que existen.
Development of renewable energies is essential if we want to slow down climate change and fight for all the planet’s inhabitants to have access to electricity.
But there are still people who doubt the efficiency of clean energies. Below we debunk some of these false arguments of solar photovoltaic energy:
Today, renewable energy sources are cheaper than conventional sources in most parts of the world. More than two-thirds of the world's population lives in countries where solar and wind energy are already the most competitive sources of energy. And if the environmental and social costs of energy sources are internalized and taken into account, renewables are the most competitive energy sources worldwide.
Over the past decade, the cost of photovoltaic modules has fallen by 94%
It is not true that forests are destroyed in order to install solar plants. There is no report from solvent public or private bodies that the growth of solar energy contributes to deforestation. On the contrary, solar plants are often installed in arid environments, with little or no vegetation.
ACCIONA's experience reveals that if a specific project has required the felling of a tree or species of natural interest, this has been compensated for by the planting of new trees in far greater numbers than those affected.
The phenomenon of deforestation is internationally linked to the abusive exploitation of tree masses or to the unsustainable extension of farmland, if not to droughts caused by climate change that renewable energies, such as solar energy, help to curb.
Solar plants are often installed on land without a previous use or even in desert environments where they don’t compete with livestock or agricultural activities.
To this day, there has been no known cases of conflict of interest with the agricultural sector. On the contrary, solar energy is increasingly an ally of farms, as it allows local applications linked to water pumping, automation of irrigation systems, etc.
On the other hand, there are situations where photovoltaic plants use animals like sheep and goats to keep the land, on which they are installed, natural.
Evidently, solar plants do not usually function at night, in the same way that wind farms do not operate when there’s no wind blowing. But the progress in developing storage technologies and falling costs are making it possible, when there is no immediate demand, to store the electricity produced and supply it later, when the user needs it, even if that is at night or when there is no wind.
Also, the complementarity between different renewable technologies is one of their main virtues and they are perfectly combinable so the best solution can be arrived at in any case.
Modern photovoltaic panels are becoming more and more efficient, so that, under standard conditions, the time it takes for a panel to generate the energy used for its production is calculated in about two years, with a useful life of more than 25 years, during which it will continue to generate energy with sunlight as the only fuel, clean, free and inexhaustible. The main components of a photovoltaic panel are silicon, aluminum, glass and copper, so its manufacture does not suppose an especially polluting process that requires protection and safety measures beyond those for a conventional industrial process.
Once the photovoltaic panel’s useful life is over, its components are classified as non-hazardous waste and are recoverable at rates of up to 95% or more.
In the last decade, photovoltaic solar energy has experienced a drastic reduction in costs that has made it, along with wind power, one of the energy technologies with the most promising future.
Thus, if the installed photovoltaic capacity in the world stood at 940 GW at the end of 2021, the International Energy Agency forecasts that by 2040 it will have increased sixfold, to over 3,000 GW (and even 4,800 MW in its most sustainable scenario).
In photovoltaic solar panels, peak capacity refers to the amount of kW installed, whereas nominal capacity refers to the capacity of the inverter (the electrical equipment that converts the electricity generated by the panels so it can be used by consumers).
In principle, nominal capacity defines the limit of the plant (one cannot produce more than the inverter can convert). Nevertheless, photovoltaic facilities always install a peak capacity greater than the nominal – more panels – to assure 100% of inverter capacity is used.
A solar photovoltaic plant will be well designed if the peak capacity – panels installed – ensures the inverter can function at 100% capacity whenever it is required.
We use sunlight to produce the energy with which we’re fighting the climate emergency, leading the transition towards a low-carbon economy. We have built some of the largest photovoltaic plants on the planet