An explainer on Green Hydrogen: Will it become the “fuel of the future”?

An explainer on Green Hydrogen: Will it become the “fuel of the future”?

If you have been following the news lately, you must have come across the visuals of the Union Transport Minister Nitin Gadkari going to the parliament on a Toyota Mirai, a hydrogen-powered car in late March. We have heard of electric cars but the concept of hydrogen-powered cars was new to everyone’s ears and it created an instant buzz in response to the claims that it can reduce fuel expenditure from ₹100 to ₹10 per litre.

So what exactly is green hydrogen and why is there so much buzz about it?

Firstly let’s understand the scientific process of obtaining green hydrogen. It’s fairly simple – take loads of water, pass electricity through it, and voila! You’ll get the constituent Hydrogen and Oxygen and you can bottle them up after liquefying.

But why is it called green hydrogen? Well if the electricity required for the electrolysis of water comes from renewable sources, we call it ‘Green Hydrogen’. The thing to note here is that the electricity required for this electrolysis has to be strictly sourced from renewable sources like solar, wind etc. to make it eligible to be called ‘Green Hydrogen’. It cannot be sourced from electricity generated by burning coal.

Now you must be thinking what can you do with this hydrogen and how can it propel cars? Well, just like you have fuel tanks in conventional internal combustion engine vehicles, for Hydrogen-powered cars you have a similar fuel tank that can fill up hydrogen in less than 4 minutes. What is special about a hydrogen-powered car is the fuel cell. The fuel cell converts the hydrogen to electricity which in turn powers the motor. We call hydrogen-powered cars ‘FCEVs’ or Fuel Cell Electric Vehicles.

Now you must be thinking, we are first converting electricity to produce Green Hydrogen and converting the same Hydrogen to electricity to propel cars. Is it really worthwhile to do so? So let’s compare hydrogen-powered cars with normal EVs. For every kilogram of lithion-ion, a modern car battery can store 250 watt-hours. A kilogram of Hydrogen, on the other hand, can store around 33,200 watt-hours of energy. Yes, you read that right, it is more than 10 times what a lithium-ion battery can hold per kilogram. Also, a semi-trailer in the US with a 500-mile range powered by hydrogen will take 15 mins to refuel compared to 6 hours recharging time for a similar EV semi-trailer.

So if indeed, green hydrogen is so efficient, why is Elon Musk vehemently rejecting the possibility of using hydrogen as a fuel?

Well firstly, the problem that Elon Musk has with hydrogen is storage. Now it can be interpreted in two ways-storage of large tanks of hydrogen or storage of hydrogen in fuel cells to propel cars. Reports suggest that he is referring to the latter.

So what is the problem with storing hydrogen in cars? Well, the biggest risk is that Hydrogen is a highly inflammable gas. You may say ‘So is Petrol and Diesel, what’s the difference?’. The Minimum Ignition Energy(MIE) for the hydrogen-air mixture is 0.019mJ whereas for petrol it is 0.1mJ. The other way to say it is that Hydrogen is almost 5 times as inflammable as petrol. Was Musk referring to this or the logistical challenges of storing Hydrogen? We can’t say. But definitely, he is not okay with the idea of storing hydrogen.

Now that we have fairly understood the risks and advantages of using Hydrogen as a fuel, let’s understand India’s aspirations and policies on the same. Last year, the Power Ministry of India released its National Green Hydrogen Policy which aimed at producing 5 Million tons of Hydrogen fuel by 2030. We already produce a lot of hydrogen, but it’s not ‘green’ but ‘grey’.

Grey hydrogen is basically the hydrogen that is obtained from Natural Gas through a process called Steam Methane Reforming(SMR) in which Methane from Natural Gas is heated with steam to produce a mixture of Hydrogen and Carbon Monoxide. The problem here is that all the emissions from this process in the form of Carbon Monoxide are released into the air whereas, for green hydrogen, the only emission is water. Unfortunately, grey hydrogen accounts for approximately 95% of the total Hydrogen produced in the world at this time.

India imports $8 Billion worth of Natural Gas and 50% of natural gas in India is consumed for the production of grey hydrogen. So for India, switching to Green Hydrogen will not just reduce emissions but also significantly bring down the import bill. Secondly, to produce Green Hydrogen you just need water and electricity and we have a long coastline to access seawater and ample sunlight. So green hydrogen does make sense to us. Whether it is fuel for cars or for producing steel is a question that can be answered later but in principle, we can explore this option for future energy needs.

Experts suggest that in India, green hydrogen can be used to decarbonize heavy industries like steel, cement, oil refineries, and fertilizers, etc. Conglomerates like the Adani and Reliance Groups have already announced investments in green hydrogen of over $70 Billion each by 2030. But is it really viable? How will the hydrogen be stored? What are the costs involved? Will it be financially viable for future energy demands? Green Hydrogen production in India is still in its infancy and it will take a minimum of 5 years to answer all these questions.

Now coming to the topic of discussion – will it really be the fuel of the future? Well for starters, let’s just say there is ample scope in the long-range heavy vehicles(trucks) space primarily because of two reasons – it can refuel in 15 minutes and can also store more energy as compared to EVs. For cars? Well, Toyota Mirai is expected to cost around ₹60 Lakhs and unless the price of such FCEVs goes down anywhere to ₹20 Lakhs we will not see a lot of them on the roads. Moreover, it will be directly competing with EVs and it will be a tough fight for FCEVs to sustain. So, to sum it up, green hydrogen is definitely a good option for our country but whether we’ll be able to see hydrogen-powered cars in the mid-term future- only time will tell!

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