Hydrogen (H) is the first element in the periodic table of elements; with one proton in the nucleus and one electron in the shell, it is the lightest and most abundant element in the universe. It is in him that many scientists and politicians see a solution for alternative energy sources that would meet global energy needs without further environmental pollution. Since this is a largely unknown technology to the public, I believe it is of great importance to shine a light on its possibilities.
First of all, the technology used to obtain electricity from hydrogen is not new. It has been in use since the 19th century. The first hydrogen internal combustion engine was built in 1807, and the debate over the use of hydrogen from electrolysis to replace coal appeared as early as 1863. As early as the 1920s, Norway and China produced huge electrolysis devices with a capacity of more than 10 megawatts to produce fertilizers for industry using hydropower. Such and similar periods in our industrial history, in the 70s of the last century, began to be called cycles of "hype" in which enthusiasm for the potential of hydrogen as an energy source is aroused. Because of the cost of its production, everything is given up again. The last such "hype" occurred in this century, at the time of "oil peaks" and in 2003 when it was announced (especially in the US) the launch of large investment cycles in hydrogen. The International Petroleum Games have also triggered the idea of switching to hydrogen as an energy source in international sanctions. With the economic crisis of 2008, this also died down, and investments in hydrogen began to fall again during that period. A table with accurate data can be found on Carbon Brief, who conducted a huge in-depth analysis on this topic.
Contrary to the expectations of conspiracy theorists, hydrogen technology has never taken root in the mainstream - not because some elite group that secretly runs the world has not allowed technology to develop - and vice versa for those who would like to think the capital of companies for the processing and sale of fossil fuels - the technology simply did not come to life because it is too expensive and often energy inefficient. For example, to meet climate targets (stopping warming to below 2 degrees Celsius), it would be necessary to produce 36,000 terawatt-hours of electricity. That's 38 percent more electricity than is produced worldwide today. They calculated so in Bloomberg NEF.
It seems, then, that not all hydrogen is green technology. Moreover, given its availability, scientists were forced to attribute the entire long color to hydrogen. So we have green, blue, gray, pink, yellow, purple… hydrogen.
Only green hydrogen is environmentally friendly. It is created by electrolysis, a process that separates water into hydrogen and oxygen with an electric current, using energy obtained from renewable sources. On the other hand, blue hydrogen is mainly produced by reacting methane in gas with steam and then capturing and storing the resulting CO2 emissions. In the methane vapor reaction, the most common method, fossil gas is burned to stimulate the process and used as a raw material. Currently, most of the hydrogen produced by human production in the world is not green or blue, but it is obtained from fossil fuels without any capture and storage of CO2. Production methods based on carbon, lignite, and carbon-free gas are called "black", "brown," and "gray".
According to the International Energy Agency (IEA), 76% of hydrogen comes from gas and 23% from coal - the latter is mostly in China - and only 2% comes from electrolysis. Less than 0.7% of current hydrogen production comes from green or blue stocks with low carbon content. Hydrogen can also be generated by nuclear energy to drive electrolysis. According to the IEA, there is no "determined color" for hydrogen produced by nuclear energy, but reports have variously called it "yellow," "pink," and "purple." And there is "turquoise" hydrogen, created as a by-product of methane pyrolysis, which uses heat to split fossil gases into hydrogen and carbon. In addition to the basic color palette, there are a handful of other production methods - some of which are low-carbon - that could contribute to future hydrogen demand. Turquoise hydrogen has the potential for low emissions if the process is powered by renewable energy or nuclear energy, and the resulting carbon is stored. However, a recent study concluded that, like blue hydrogen, it would continue to generate significant emissions due to the production of gas used to provide the heat needed for the process.
According to the Carbon Brief, a report by consulting firm Lucid Catalyst states that the amount of hydrogen needed to achieve international climate goals is "much higher than can be produced by renewable energy sources", which makes nuclear hydrogen necessary. It is a pity that the European Union concluded that nuclear energy is not green just this year, while gas, for example, is. Nuclear energy is a risk due to the human factor and potentially catastrophic consequences. However, if the real risk of nuclear power plants were proportionally high to moral panic on the same topic, then and only then would nuclear energy be a real reason to panic. Thus, if we compare the number of nuclear power plants on the planet and the number of catastrophic accidents, it seems that you have a higher chance of dying in a car and similar examples of unsafe human practices than in a nuclear explosion.
But when we talk about the economic viability of hydrogen, it should be borne in mind that the cheapest "gray" hydrogen - the one obtained from coal. Its price is about 1 USD per kilogram - if it is obtained from Middle Eastern gas, but it reaches as much as 3 USD per kg in some regions. For China and India, which import most of their gas supplies, coal-based hydrogen is usually the cheapest option. Gray hydrogen can turn blue if the carbon capture and storage method are used, but this increases the cost by approximately $1.5 per kg, according to the IEA. For comparison, the Agency states that green hydrogen obtained from solar energy or land wind usually costs between $2.5 and $6 per kg.
Also, the Carbon Brief has conducted a meta-analysis of numerous studies on hydrogen as an energy source. The most interesting, it seems to me, is the difference they noticed when comparing the IEA and BNEF data for green hydrogen. The difference comes down to estimating the costs of installing electrolysis devices, which are twice as high in IEA forecasts, with the addition of slightly higher electricity price assumptions. In order for the investment in electrolysis devices to pay off, the result would have to be stable and relatively cheap electricity. If the machines do not work all the time, the hydrogen cost is higher than is currently commercially viable. Also, the cost of transport should be added to hydrogen's production price, which means that green hydrogen is certainly the most expensive form of hydrogen. Transport at a distance of more than 1500 km becomes completely unprofitable.
In theory, writes the Carbon Brief, "hydrogen has the potential to decarbonize everything, from the steel used to make someone's car to the gas that heats their home. However, in practice, it is unlikely that hydrogen will be used universally. Moreover, the amount needed to meet all possible low-carbon applications would probably far exceed the amount available, even if production is significantly increased. The question, then, is no longer at all whether you are for hydrogen or against it. The question is where it is necessary to use hydrogen and where it is too expensive or environmentally unsatisfactory. Transport is certainly something that could take away 25 percent of the carbon produced, and the power sector could consume 30 percent, as could industry. But buildings are likely to be heated in other ways, so according to Bloomberg research, their share of hydrogen consumption by 2050 will be just 15 percent.
Given the climate target of stopping warming to an average of 1.5 degrees Celsius per year, according to Bloomberg, hydrogen would meet only 24 percent of final global energy demand. Charts explaining this are available at this link. According to an IEA survey called Energy Technology Perspectives published in September 2020, hydrogen consumption is projected to meet less than 7% of total energy demand by 2050, of which transport (44%), industry (28%), power ( 19%) and buildings (9%). This is a much stricter estimate than Bloomberg's. The difference is infrastructural, and it relates to the cost of labor. That is, the infrastructural loads calculated by the International Energy Agency are more expensive than those that Bloomberg thinks can be built cheaper. Such assessments also contain poorly visible social policies. The very fact that public administration bodies do not go to the maximum cheap price of production testifies to us again that something has changed in Europe. This is also clear from the non-existence of the issue of the price of hydrogen technology. I guess it is calculated that investments in this will pay off through a smaller financial burden on the health system and social peace.
Comentarios