Hydrogen fuel: The Energy Next

S K Nag

Hydrogen, the inflammable air, was discovered by eminent English natural philosopher, chemist, physicist & scientist Henry Cavendish. It is undoubtedly a potential energy source, leading to a cleaner and greener environment without consuming natural resources like Coal, Natural Gas, & Oil. The impact of Hydrogen on the environment is nothing because it emits water vapor as a byproduct along with energy. So, replacing fossil fuels to meet our primary energy demand is a lucrative and viable option. Current Energy consumption patterns across the globe are very alarming that indicates a discouraging future if not taken care now. Due to high energy demand, our natural resources are quickly depleting which needs sustainable energy alternatives to save this planet.  The world has started thinking to come out of this imminent criticality with a viable alternative to replace fossil fuels, and till the recent past solar & wind energy appeared to be a meaningful alternative. But the inherent limitations restrict their universal applications, questioning their economy of scale and compatibility of large applications. The consistency and intensity of the source are the two parameters that prohibit more comprehensive applications. Hence, this energy is considered a secondary source that complements the conventional primary energy source. For supporting critical functions independently, this may not be a feasible solution in near future. Though researchers are still trying to leverage these sources to the fullest, nevertheless as of now no breakthrough is achieved.  Therefore our dependence on Thermal power plants are still existing to support primary energy requirements consuming coal and other important natural fossil fuels. The world’s Coal reserves in various countries lie between 31 and 452 years. China is on the lower side & Russian federation is on the higher side. India has a coal reserve of 100 years, an Oil reserve of around 17 years & Natural Gas reserve of 40 Years. The formation of coal is a lengthy process that takes millions of years, so a new generation of coal is unimaginable and impossible to replenish.

So, what next?  That is why Hydrogen is gaining importance. Hydrogen gas is an active alternative to replacing coal-based energy due to its high energy content; though it has been used in space missions for a long time, its domestic use needs many challenges to overcome. Atmospheric air does not contain Hydrogen. The content of Hydrogen in air is 0.00005% (which is negligible). So, unlike other gases, Hydrogen cannot be sourced from air. Hydrogen is produced as a byproduct in some chemical processes though, still more generation is needed to meet the holistic energy demand. Therefore a planned commercial production process is essential.

Hydrogen has eight types of classifications. Green, Blue, Grey, Brown, Black, Turquoise, Yellow, & Pink basis their production method, input energy used to generate and the safe disposal of end products, CO2, & Carbon. Out of all these, only green and yellow are considered environmentally-friendly and known as renewable Hydrogen; others are not. It uses water as the primary source and renewable electricity (Solar & Wind) as input power to carry out electrolysis, which thus produces Hydrogen and oxygen without impacting the environment. The Yellow Hydrogen production line uses only solar energy. Other hydrogen generation processes release carbon dioxide or Carbon along with Hydrogen impacting the environment.

Hydrogen and power generation chemistry is simple, but the entire value chain has a lot of complicated steps and challenges that need to be overcome. These are Production challenges, transportation challenges, and storage challenges. The first criticality is to overcome the sourcing of Hydrogen. In its production process, the electricity required to electrolyze water would be 39 kWh to produce 1 kg of Hydrogen, which can produce 23 kWh of electricity. This means 39 kWh of electricity is needed to produce 23 kWh of electricity. Besides, 30% of process waste must be added extra. The electricity consumption and production mismatch make the economy of scale doubtful.

The next most significant challenge is the transportation of Hydrogen, known as inflammable air, so it needs a high accuracy level and meticulous planning to manage its logistics. The world still needs to be ready to transport Hydrogen by road. Because of high flammability, any nano degree of negligence can trigger a devastating blast impacting a wide area around it. Therefore, a dedicated pipeline corridor must travel from its source to the consumption point. Hydrogen has high embrittlement criteria which reduces the surface thickness of the holding container very fast. To make it a storage friendly chemical a chemical conversion is necessary and requires a lot of energy to convert and reverse the Hydrogen for use. Another alternative is to set up a captive hydrogen power plant (CHPP) next to its source, avoiding logistic issues. However, the quantum of hydrogen generation and setting up a CHPP is still not commercially feasible because of many technical challenges. The developed countries are working hard to fix this, but several years are still to be invested before its wide applications become a reality.

The third most significant challenge is its storage. Hydrogen has a very low density, necessitating a high-pressure and very low temperature (-253 deg C) controlled storage facility to adequately compress it, increasing safety concerns. Conclusively, unlike other gases, production, transportation, and storage have their in-built challenges.

Therefore, the sustainable energy mission and decarbonization objectives should go together and invite active application of mind without any diplomatic or political influence. Any unnecessary and unmindful act may jeopardize the entire journey, including the present and future of this mission. So, the commercial application must remember the Chemistry of Hydrogen to proceed further. We should not ignore the promise it holds as a clean alternative to fossil fuels and reduce greenhouse gas emissions. The challenges mentioned above look insurmountable, but the world must devise suitable technical solutions for widespread adoption in the long run to meet its global energy needs of 12K Million tons of oil equivalent.

(Author is Industrial Engineer, Fellow Valuer, Chartered Engineer, BEE approved Energy Expert and Industry Mentor. The views expressed are personal opinion of the author. He can be reached at saibal.iim@gmail.com)