Exploring the Various Shades of Hydrogen on the Sustainability Spectrum
The green hydrogen industry is a fast-growing market. According to data from the consultancy LCA, this niche could add R$7 trillion to the country’s GDP by 2050. To talk about the subject, the interviewee is Pedro Luiz Côrtes, professor at the School of Communications and Arts (ECA) and the Institute of Energy and Environment (IEE) of the University of São Paulo. He says hydrogen is not always green – it can be obtained and used in a variety of ways. Two examples that the professor mentions are hydrogen on board and hydrogen through electrolysis. The first is “produced onboard vehicles through a fuel cell system that converts hydrogen and oxygen into electricity, powering an electric motor,” he says. The second, through electricity, “separates water molecules into hydrogen and oxygen. In this way, oxygen is released into the atmosphere and hydrogen is used to produce electricity”, adds Côrtes.
The meaning of colors
The colors are divisions that were made to determine the process of obtaining hydrogen. There are six different types, with gray being historically more common and used, “it is obtained from the burning of fossil fuels, mainly natural gas, and is not considered in principle a sustainable fuel exactly because of CO2 emissions”, explains the teacher.
Moving up the sustainability scale, we have blue hydrogen. It also uses fossil fuels in production, but prevents carbon from accumulating in the atmosphere. “If this CO2 is recovered, we have blue hydrogen, produced from natural gas with a process of capturing and storing this CO2”, adds Côrtes.
Other forms are pink hydrogen, produced using nuclear energy; white, obtained from geological processes, such as the release of gases from magma; and yellow, obtained from mixed sources, which is what we have in our homes, considering that Brazil has both renewable and fossil sources in its energy matrix. All of these are more sustainable than gray.
Finally, we have green hydrogen, which has the greatest potential because it has completely renewable energy as a source and does not emit any carbon. Although it is still an expensive process, the expectation is that production will become cheaper and more efficient over time. To this end, Brazil – due to its energy potential and abundance of rivers – positions itself as a future base for green hydrogen. According to the LCA, the country should have a R$70 billion surplus this decade. Beyond 2030, the expectation is that the numbers will increase even further.