The renewable geothermal energy source will be tested in Brazil as a way to reduce the costs of using air conditioning in commercial buildings and residences in general, which are very high throughout the country.
Making use of the thermal energy that is present in the basement, with the purpose of climatizing internal environments, is a viable alternative to reduce expenses with the use of air conditioning in buildings and commercial buildings, as well as in apartments and other types of residences. with the use of renewable energy. Surface geothermal air conditioning has been widely used in temperate countries such as Europe, the United States, Japan and Canada, and will be tested for the first time in Brazil. The test will be carried out in the laboratory building Cics Living Lab, of the Center for Innovation in Sustainable Construction (Cics) of the Polytechnic School of the University of São Paulo (Poli-USP), which is being built inside the campus of Cidade Universitária, in the west zone. from Sao Paulo.
According to Alberto Hernandez Neto, mechanical engineer at the Department of Mechanical Engineering at Poli-USP, in Brazil, air conditioning is responsible for 40% to 50% of the energy costs of a commercial building, in addition to 20% to 25% of a residence annually.
The geothermal energy system is able to reduce this high energy consumption, bringing savings and less impact to the environment, as it is a renewable energy source.
In a study carried out by Empresa de Pesquisa Energética, a service provider to the Ministry of Mines and Energy (MME), in 2018, it showed that residential energy consumption alone, due to air conditioning, reached about 18.7 terawatt-hours. (TWh) in the previous year. This data is equivalent to all photovoltaic solar energy generation in Brazil in 2021 and could reach 48.5 TWh in 2035.
Geothermal energy system test scheme by Cics
The Cics Living Lab will use heat exchange foundations during the testing of the geothermal energy system. A fluid, such as water, for example, will circulate through the tubes installed inside the piles that make up the foundations of the building, thus promoting the exchange of heat between the inside of the building and the basement area.
Civil engineer Cristina de Hollanda Cavalcanti Tsuha, from the Geotechnics Department of the São Carlos School of Engineering at USP, responsible for evaluating this technology, explained that the operation of the geothermal energy system is based on the difference in temperature between the two parts. The research developed received support from Fapesp. The energy is transported through a geothermal heat pump, responsible for carrying out the exchange of heat between the basement and the internal area of ??the building.
With this, the pump is responsible for cooling or heating the environments, very efficiently. Alberto Hernandez made a comparison, where he could say that the refrigeration cycle is very similar to that of a domestic refrigerator, but the main difference is that the geothermal heat pump can be reversible, that is, it cools or heats the internal environment. According to Alberto, a heat pump consumes about 40% less energy than a conventional air conditioner.
Use of geothermal energy is old
Despite appearing to be a super and new technology, the practice of making use of underground thermal energy is very old. It is estimated that the world’s first geothermal power plant was built in Italy in 1904.
The facilities at the time were responsible for capturing hot water or steam from the magma, inside the Earth to move the turbines that drove the generators and produced this renewable energy. However, only volcanic regions or where there are geysers are viable for maximum use of this energy.
Around 25 countries currently have geothermal energy systems to produce this renewable energy source, among them the USA, Iceland, Japan and New Zealand.
* This article has been republished from the website Pesquisa Fapesp Magazine under a Creative Commons CC-BY-NC-ND license.
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