A number of nations have plans to switch to carbon-free energy technologies as a response to the urgency of addressing climate change. In addition to utilizing wind and solar power, favourable hydrogen technologies are receiving a lot of attention and have already been implemented in some regions of the world.
The idea of using hydrogen as a clean, low-carbon energy resource to meet the world's energy needs, replacing conventional fossil fuels in a variety of applications, and making up a significant portion of a clean energy portfolio is referred to as the "hydrogen economy."
In recent years, two significant developments have contributed to the expansion of hydrogen energy technologies: While the importance of reducing greenhouse gas emissions has increased, the cost of producing hydrogen from renewable energy sources has decreased and will continue to do so.
It has a particularly high energy density and powers the stars. It is non-polluting and may be of assistance to us in addressing our planet's energy crisis. However, there is only one flaw: it isn't not difficult to create. However, developments in the technology for producing it in a clean manner using renewable resources are paving the way for a new era.
Hydrogen is the lightest and most abundant of the many elements that make up matter. It is mostly gas and makes up almost 90% of the visible universe. It is a two-atom molecule (H2) that burns similarly to methane in an oxygen-rich atmosphere like ours. It has the highest energy content per unit of weight of any conventional fuel, three times higher than gasoline.
However, the star-powering nuclear fusion reactions also use hydrogen as a propellant. Therefore, the source of the sun's renewable energy that Earth receives each day is this extraordinary element. Additionally, it is combined with oxygen in fuel cells to produce water and electric energy. Due to its characteristics, green hydrogen has the potential to play a significant role in a world with zero emissions.
In terms of decarbonization, electrification using renewable energy sources will be the primary and most effective route. However, there are some end uses that have been more challenging to decarbonize through direct electrification up until this point.
Green hydrogen can enter this area to achieve complete decarbonization. These are the so-called "Hard to Abate" industries, which mostly affect the aviation, maritime, and industrial sectors.
Hydrogen that is green and has no effect, there is only one issue. Regardless of its overflow on Earth hydrogen doesn't exist normally all alone. Hydrocarbons (carbon and hydrogen) and water (molecules of hydrogen and oxygen) are the only substances in which it can be linked to other elements. Hydrogen must be extracted in order to separate it from other elements found on Earth. This separation process requires energy, which results in costs that are both financial and often environmental.
Hydrogen is regarded as an energy carrier rather than a source of energy, like solar or wind power, due to the fact that it is not found in its pure form in nature and that its production requires the contribution of another kind of energy.
Just the supposed "green hydrogen," which is gotten by isolating it from water through a course of electrolysis controlled by sustainable power, is completely zero effect, without dirtying outflows and without polishing off valuable regular assets.
The scientific and technological communities have been working for some time to simplify and reduce the cost of producing green hydrogen. As a result of the significant progress that has been made in recent years, this objective now appears to be almost within reach. As a result, many experts believe that the oil era is coming to an end and that a new energy era powered by hydrogen is beginning.
What is hydrogen's workings?
The reforming of methane or the gasification of coal, both of which produce significant carbon dioxide emissions but are currently the least expensive options, are the sources of approximately 95% of the hydrogen that is utilized on Earth today, the majority of which is utilized in industry.
However, there are additional methods for obtaining hydrogen, including thermochemical processes and, most importantly, water electrolysis. This involves electrolysers, which are systems that need a certain amount of electrical energy and must be powered by renewable sources like wind power or photovoltaic in order to be sustainable.
From a cost standpoint, large-scale hydrogen production plants are not yet competitive with conventional plants. However, the situation is rapidly changing as a result of the anticipated decrease in the price of electrolysers, the significant improvement in the efficiency of photovoltaic cells and wind generators, and the subsequent decrease in the price of kWh generated by renewable sources.
How do such plant’s function?
The electrolyser or electrolytic cell in the heart is where water is separated into its two components, hydrogen and oxygen. Two electrodes, a positively charged anode and a negatively charged cathode, are brought into contact with the water. The molecules are separated into H+ hydrogen ions and OH- hydroxide ions by the electrical current.
Through a reduction reaction at the cathode, the hydrogen ions acquire electrons and transform into gaseous hydrogen. Through oxidation, the hydroxide ions at the anode release electrons, resulting in oxygen formation.
A portion of the electricity produced—for instance, the electricity produced beyond the capacity that can be fed into the grid—can be used to power the electrolytic cell if it is situated close to a renewable energy facility .As a result, the produced hydrogen can be used as a chemical energy storage facility or as a fuel to generate high-temperature heat or as a raw material during the steel production process.
Benefits of green hydrogen is the fuel with the highest energy density: It is extremely efficient and does not produce any emissions.2.4 kg of methane or 2.8 kg of gasoline have the same amount of energy in 1 kilogram.
The capacity to convert electrical energy into hydrogen makes it the most effective energy storage medium for storing excess electricity generated by renewable sources. Hydrogen's high conversion efficiency is another valuable property. The mechanical yield of gasoline or diesel-powered combustion engines ranges from 20% to 35%, whereas up to 60% of the chemical energy of hydrogen is converted into motive power in a hydrogen fuel cell-powered automobile.