In the face of climate change, pollution, and the scarcity of natural resources, the clean energy Clean energy emerges as a necessary and promising alternative. But what exactly is clean energy? What are its types, advantages, and challenges? And how can it transform our future? Below, we provide all the answers.
What is clean energy?
Clean energy is energy that emits little or no pollutants and does not release CO₂ into the atmosphere, the pollutant responsible for global warming. Therefore, it is considered a low-carbon source and aligned with sustainability goals. Among the main types of clean energy are solar, wind, hydroelectric, geothermal, biomass, and, in some contexts, nuclear.
These sources are continuously regenerated and, unlike fossil fuels such as coal, oil and gas, do not depend on finite reserves, nor do they produce large amounts of CO2, thus contributing to the maintenance of a sustainable environment.
However, the label "clean" needs to be used with caution. This is because there is no rigid definition in laws or regulations. What is classified as clean energy changes according to the country, the context, and the political objectives. In Europe, for example, the classification usually follows technical criteria, such as emission limits, in addition to broad targets linked to the energy transition and the pursuit of carbon neutrality.
As a result, clean energy has become a broad concept, useful for guiding public policies, but one that requires attention to avoid losing clarity. It often appears as renewable energy or green energy, although not all clean energy is renewable; nuclear energyFor example, it does not emit CO₂, but it uses non-renewable fuel.
The concept of clean energy began to gain prominence in the 1970s, with the oil crisis and increased environmental concern. Over the years, the debate on sustainability and the effects of climate change has led governments, companies, and society to seek alternative and less polluting sources.
Solar energy is a clean energy source.
Solar energy is one of the most accessible and universal clean energy options. Although the manufacturing of solar panels can generate greenhouse gases, they become virtually emission-free once they are operational.
Solar panels capture sunlight and convert it into usable electricity. This requires available roof space or elevated, unoccupied land facing the sun. Solar thermal technology can also be used to directly heat buildings or water reservoirs.
Geothermal energy
Geothermal energy, obtained from the heat deep within the Earth, is another clean energy source, available from hot springs to volcanic zones around the world.
To generate electricity or heat spaces, the process is simple: the ground is drilled until regions are reached where the temperature is naturally high, a result of geological activity and the heat stored in the rocks. The water present underground, upon coming into contact with these hot layers, turns into steam. This steam is directed to the surface through pipes and moves turbines that generate electricity.
One of the reasons why geothermal energy is renewable is that we can extract heat from the Earth, use it, and then inject water underground to keep the process going. This makes the heat source inexhaustible, provided we manage it properly. It is underutilized in Brazil.
Hydro-electric energy
Hydropower transforms the energy of flowing water into electrical energy. This magic happens inside hydroelectric power plants, which are usually connected to large water reservoirs. When water is dammed in a reservoir, the water and the energy it contains can be stored until we need it.
The movement of water powers turbines that generate electricity. The higher the water pressure, the more energy is produced. Therefore, it depends on rainfall and river flow.
Although considered clean energy, the construction of hydroelectric power plants results in natural interventions and affects the natural landscape, as well as fish species. Due to the environmental impact, some question how ecologically sound hydroelectric power is.
wind energy
Wind energy is obtained from the kinetic energy of the wind, produced by the effect of air currents. Like solar energy, wind energy is an inexhaustible, yet intermittent, renewable energy source, as it depends on wind intensity.
Wind turbines can be installed on land or at sea. Onshore wind turbines are technically simpler to install, but offshore turbines are more efficient in terms of energy production.
Ocean energy
Ocean energy can generate large amounts of clean energy, after all, it is obtained from the waters of seas and oceans. Waves, currents, tides, and temperature variations are enormous reservoirs of energy from which, with the use of appropriate technologies, a quantity of energy can be extracted to meet global energy needs.
Despite its promise, there is no large-scale operation in Brazil. Technologies are being studied around the world.
Bioenergy
Imagine a world where food scraps and garden waste not only decompose but also light your home. This isn't science fiction; it's the promising reality of bioenergy, and it's transforming the way we think about energy and waste.
Bioenergy uses organic waste of plant or animal origin to produce biogas, which generates electricity. It is one of the cheapest and most environmentally friendly forms of energy generation in thermal power plants.
Biomass energy, also known as bioenergy, is considered renewable because it derives from organic sources. Unlike fossil fuels, which take millions of years to form, bioenergy sources can be grown, harvested, and regenerated in a few months or years.
Read also What are fugitive emissions?
Clean energy in Brazil
Approximately 80% of Brazil's electricity comes from renewable sources. The country typically includes sources such as hydroelectric, wind, solar, and biomass under the umbrella of clean energy. As a result, Brazil occupies a prominent position in the clean energy transition within the G20. The country stands out as one of the main examples demonstrating that it is possible to rapidly expand renewable generation, reduce emissions, and meet the growing demand for electricity. This assessment comes from the International Energy Agency (IEA).
The industrial sector appears to be one of the sectors that most incorporates clean energy sources in the country. The National Energy Balance (BEN) for 2025, released by the Ministry of Mines and Energy (MME) and EPE, indicates that... manufacturing In 2024, the country used 64,4% renewable energy, a similar rate to 2023 (64,7%). Electricity accounted for 22% of industrial consumption, with 88,2% coming from renewable sources. Sugarcane bagasse was the second main source used (21,3%). Other sources included black liquor (9%), firewood (8,8%), coal (11,9%), natural gas (9,4%), charcoal (4%), fuel oil (1,3%), and other sources (12,3%).
How the country operates:
- hydroelectric plantsMost of the energy produced in Brazil continues to come from hydroelectric plants. The main plants are located in regions with large river basins, such as the North and the Central-West. Belo Monte (PA), Tucuruí (PA), Jirau (RO), Santo Antônio (RO), and Itaipu (PR/Paraguay) lead the way.
- WindWind energy has become a symbol of "new" clean energy in the country. The Northeast dominates production, with Rio Grande do Norte, Bahia, Ceará, and Piauí standing out. Rio Grande do Norte alone concentrates one of the largest wind farms in the world. There is also expansion in the South, mainly in Rio Grande do Sul.
- SolarSolar energy has skyrocketed in states with high levels of solar radiation. Minas Gerais is now one of the national leaders, followed by Bahia, Piauí, Pernambuco, and Goiás. The sector is growing both in large power plants and in distributed generation systems installed in homes, businesses, and condominiums.
- Biomass e biofuelsBiomass, primarily derived from sugarcane bagasse, is concentrated in the Central-South region, especially in São Paulo, Minas Gerais, Goiás, Paraná, and Mato Grosso do Sul. These states lead in ethanol and biodiesel production and form the basis of RenovaBio, a policy that classifies biofuels as clean energy due to their lower lifecycle emissions.
Alutal and the future of clean energy
Alutal's vision aligns with what humanity needs most: the urgent shift from dependence on non-renewable energy sources to clean and sustainable energy sources. This commitment guides every solution we offer in the market.
The company provides high-precision solutions, such as industrial thermocouples, 4–20 mA temperature transmitters, PT100 sensorsSpecial pressure switches and thermowells, all designed to ensure efficiency, safety and reliability in renewable generation operations.
Thermal sensors from the TRP line and transmitters from the ATT series, for example, are used to monitor temperature in solar panels, wind turbines, hydroelectric turbines, and biomass boilers—critical steps in maintaining the stability and performance of these plants.
With a portfolio focused on the energy transition, Alutal positions itself as a strategic supplier for projects seeking to reduce emissions and operate with greater technical precision.
FAQ
Solar energy is considered the cleanest energy source because it does not produce harmful emissions or pollution during electricity generation. However, it is worth noting that the production, transportation, and disposal of solar panels can have an environmental impact, but this is generally considered minimal compared to other energy sources, such as fossil fuels.
Hydropower is a clean energy source because it generates electricity without emitting greenhouse gases or other pollutants: it helps reduce the consumption of fossil fuels, thus reducing air pollution and mitigating climate change. Furthermore, it provides renewable and unlimited energy over time.
Biodiesel is a liquid fuel produced from renewable sources, such as new and used vegetable oils and animal fats, and is a cleaner substitute for petroleum-derived diesel.
