The function of photovoltaic solar energy is to use sunlight as a source of electricity. The easy maintenance, the useful life of the equipment and the ecological advantage make the system worthwhile in many cases, although the initial investment value is high — and this usually weighs on most people.
And, even if on a smaller scale, production also takes place on cloudy days. So about that, you don’t have to worry.
Find out below everything you need to know about solar energy, including its advantages and disadvantages.
Solar energy: know all about it
What is solar energy?
In 1839, the French physicist Alexandre Edmond Becquerel discovered the photovoltaic effect, the potential of sunlight to generate electricity. But it was not until 1954 that the American engineer Russell shoemaker Ohl introduced the first system as it is used today.
Solar energy uses a special system to capture sunlight and convert it with two main purposes:
photovoltaic solar energy: transform sunlight into electricity (it is the most used);
Solar energy heliothermic🇧🇷 transforming light into heat for water heating (it replaces, for example, the electric shower and puts hot water in the taps).
What are photovoltaic panels?
Photovoltaic panels or modules are made from silicon, a semiconductor (conducting and insulating material that can easily change electrical conduction characteristics).
“In them, on one side you have more positive charges and, on the other, more negative charges. When the sun hits, this enormous energy causes the negative charge to change sides. The movement of electrons is the electric current”, he explains Edval Elboni, coordinator of the electrical engineering course at the Instituto Mauá de Tecnologia🇧🇷
The light falls on the photovoltaic panels, but produces electric current with voltage smaller, incompatible with the appliances in your home. Therefore, it is submitted to the inverter, which changes the voltage to 127 V or 220 V.
How to install and use solar energy at home?
The system is installed by specialized companies. The first step is to calculate consumption, based on the electricity bill, to budget the best photovoltaic model. There are two options:
- off grid: night supply is guaranteed by batteries, recharged throughout the day.
- on grid: the electrical grid is connected to the local power utility.
In the latter case, there is a storage system that redirects excess energy to the utility. This guarantees supply during the night and allows the consumption of energy directly from the network in case of any problem.
This energy generated the most used by the concessionaire becomes a kind of bonus with a period of five years to be used and you only pay a minimum monthly fee.
The off grid model is still little used in homes, because of the high cost of batteries.
What is the cost of solar energy?
The installation costs of the photovoltaic solar system depend on the standard in energy consumption. In a family with four people, for example, prices can vary between R$ 16,500 and R$ 18,000. The amount covers full support, installation and equipment.
According to experts surveyed by Tiltthe return on investment is up to five years, and the system can last up to 30 years.
“Anywhere in Brazil, the sun is very good, so the average return is four to five years. But, in the Northeast, it can be three to four years”, he says. Elboni🇧🇷
Apartments can use solar energy?
Apartments can also use solar energy systems, but the installation model must be made in accordance with the building. This makes the process bureaucratic and sometimes prevents tenants from following through with the idea.
In addition, it is necessary to analyze whether there is adequate space on the land for the efficient installation of the plates and make a shared plant for everyone.
How is the maintenance of the solar energy system?
As the plates are made to last a long time, it is essential to invest in a good project to ensure that there are no problems, such as lightning strikes, but in general, the maintenance of the photovoltaic system is simple.
On a day-to-day basis, you just need to check that there are no burnt modules and, when you notice the accumulation of dust, clean them with a damp cloth in water —accumulated dirt impairs the incidence of natural light and affects the performance of the system.
What are the disadvantages of solar energy?
The main disadvantages of solar energy are:
- High initial investment🇧🇷
- Absence of energy production during the night;
- Low power generation when compared to other models: the efficiency of the system is relatively low, because it manages to transform 20% of what it captures into energy. “That’s on the best boards, but new technologies are being developed”, says Odilon Duarte, professor of electrical engineering at the PUC-RS (Pontifical Catholic University of Rio Grande do Sul)
What are the advantages of solar energy?
- Less expenses: with the payment of the minimum fee to the concessionaire, the electricity bill reduces between 90% and 95%;
- Sustainability: the system no longer uses coal and emits gases such as CO2 (carbon dioxide) and the CH4 (methane);
- Quick installation
- reliable system🇧🇷
- Do not do noiseat least not to the point of bothering you on a daily basis;
- Simple maintenance;
- Adds resale value to the property;
- Easy installation in the citywhen compared to other models (such as wind energy, for example).
The main solar energy companies in Brazil
The market for photovoltaic systems in Brazil is expanding. Among the main companies in the country, the following stand out: Canadiansolar-Brazil🇧🇷 Avex Technology🇧🇷 Jinko solar and Neosolar🇧🇷
There is also a growth of small designers, who are not manufacturers, but help quote and hire services for those who want to adhere to solar energy.
What is the rate of use of solar energy in Brazil?
The percentage of use of solar energy in the Brazilian energy matrix is still small. The index is at 1.7%, according to data from 2021 dThe ABSOLUTE (Brazilian Association of Photovoltaic Solar Energy).
“Although it represents little, it is the one that is growing the most”, says Edval Elboni🇧🇷
Source: Edval Elboni, coordinator of the electrical engineering course at the Instituto Mauá de Tecnologia; Odilon Duarte, professor of electrical engineering at PUC-RS (Pontifical Catholic University of Rio Grande do Sul).