Sometimes we hear solar energy and quickly think of electric energy produced with photovoltaic panels. And it is that photovoltaic technology has become a boom in recent years.
The accelerated decrease in manufacturing prices of the panels, together with an increase in competition and adaptation of the technology, have driven an escalation in solar installations around the world.
In Mexico, in March alone, we broke the record for electric energy generated by photovoltaic solar panels. This reached 1.6 TWh of energy settled in the National Electric System operated by CENACE; which represented 6% of the electric energy generated in the country.
However, there are other forms of use of solar energy that we rarely talk about. On the one hand, thermal heat, that is, the use of solar irradiation to produce heat that can be used in industrial processes or for domestic or commercial consumption.
Heat consumption in homes can be divided into three large groups: space heating, cooking food and heating hygienic water. Together, cooking food and heating water represent 72% of heat in homes. For this purpose, electricity, LP gas and natural gas are used, but above all firewood. This represents 46% of the total primary energy used for heat in homes.
To address this part of the demand, various types of technology have been developed that collect solar irradiation to, for example, heat water or spaces both in homes and in businesses or offices, reaching temperatures from 30º to 90º Celsius.
Photovoltaic Solar Energy and Solar Thermal Heat
In a quieter revolution than the one photovoltaic solar energy has experienced, solar thermal heat has also had significant growth. In 2017, the total area covered by collectors was 675 million square meters and a total installed capacity of 472 GWth distributed in almost 120 million installations around the world.
According to data from the International Energy Agency, the mentioned installed capacity produced 1,404 PetaJoules in 2017. It represented a reduction of greenhouse gases of 135 million tons of CO2 equivalent worldwide, particularly in China.
In Mexico, according to data from the Ministry of Energy, CONUEE, IRENA and GIZ, there is an economically profitable potential in industry, businesses and homes that amounts to almost 33 Gigawatts. This could help reduce emissions not only from homes but also from industry.
Mexican industry represents close to 31% of heat demand at the country level and requires low heat cycles —less than 150ºC— for pasteurization, cleaning, cooking or bleaching; medium heat cycles —between 150 and 400ºC— for distillation, coloring and compression; and high heat cycles —more than 400ºC— for industrial transformation processes, which solar heat technology could provide with the correct incentives and with a policy oriented toward reducing greenhouse gas emissions.
This is not all, but space is running out, and next week we will address a very interesting technology: concentrated solar energy, which allows generating electric energy by conventional means but without using fuels, using a principle and a mechanism very different from that of photovoltaic panels. Until then.
This article was originally published by Business Insider México.
Date: April 20, 2021
Original Link: https://businessinsider.mx/energia-solar-opinion-paul-alejandro-sanchez/ [offline]
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