India has announced a National Hydrogen Mission that will draw up a roadmap for using hydrogen as an energy source. The initiative has the potential of transforming transportation.

Traditionally a slow mover in frontier electric vehicle (EV) technologies, India has made an uncharacteristically early entry in the race to tap the energy potential of the most abundant element in the universe, hydrogen. Less than four months after the United States Department of Energy announced an investment up to $100 million in hydrogen production and fuel cell technologies research and development, India has announced a National Hydrogen Mission.

The proposal in the Budget will be followed up with a mission draft over the next couple of months — a roadmap for using hydrogen as an energy source, with specific focus on green hydrogen, dovetailing India’s growing renewable capacity with the hydrogen economy, government officials indicated.

And while proposed end-use sectors include steel and chemicals, the major industry that hydrogen has the potential of transforming is transportation — which contributes a third of all greenhouse gas emissions, and where hydrogen is being seen as a direct replacement of fossil fuels, with specific advantages over traditional EVs.

In October, Delhi became the first Indian city to operate buses running on hydrogen spiked compressed natural gas (H-CNG) in a six-month pilot project. The buses will run on a new technology patented by Indian Oil Corp for producing H-CNG — 18 per cent hydrogen in CNG — directly from natural gas, without resorting to conventional blending.

Power major NTPC Ltd is operating a pilot to run 10 hydrogen fuel cell-based electric buses and fuel cell electric cars in Leh and Delhi, and is considering setting up a green hydrogen production facility in Andhra Pradesh.

Why hydrogen — and its types

Hydrogen’s potential as a clean fuel source has a history spanning nearly 150 years. In 1874, science fiction writer Jules Verne set out a prescient vision in The Mysterious Island — of a world where “water will one day be employed as fuel, that hydrogen and oxygen which constitute it, used singly or together, will furnish an inexhaustible source of heat and light, of an intensity of which coal is not capable”.

The most common element in nature is not found freely. Hydrogen exists only combined with other elements, and has to be extracted from naturally occurring compounds like water (which is a combination of two hydrogen atoms and one oxygen atom). Although hydrogen is a clean molecule, the process of extracting it is energy-intensive.

The sources and processes by which hydrogen is derived, are categorised by colour tabs. Hydrogen produced from fossil fuels is called grey hydrogen; this constitutes the bulk of the hydrogen produced today. Hydrogen generated from fossil fuels with carbon capture and storage options is called blue hydrogen; hydrogen generated entirely from renewable power sources is called green hydrogen. In the last process, electricity generated from renewable energy is used to split water into hydrogen and oxygen.

The case for green hydrogen

Green hydrogen has specific advantages. One, it is a clean burning molecule, which can decarbonise a range of sectors including iron and steel, chemicals, and transportation. Two, renewable energy that cannot be stored or used by the grid can be channelled to produce hydrogen.

This is what the government’s Hydrogen Energy Mission, to be launched in 2021-22, aims for. India’s electricity grid is predominantly coal-based and will continue to be so, thus negating collateral benefits from a large-scale EV push — as coal will have to be burnt to generate the electricity that will power these vehicles. In several countries that have gone in for an EV push, much of the electricity is generated from renewables — in Norway for example, it is 99 per cent from hydroelectric power. Experts believe hydrogen vehicles can be especially effective in long-haul trucking and other hard-to-electrify sectors such as shipping and long-haul air travel. Using heavy batteries in these applications would be counterproductive, especially for countries such as India, where the electricity grid is predominantly coal-fired.

How hydrogen fuel cells work

Hydrogen is an energy carrier, not a source of energy. Hydrogen fuel must be transformed into electricity by a device called a fuel cell stack before it can be used to power a car or truck. A fuel cell converts chemical energy into electrical energy using oxidising agents through an oxidation-reduction reaction. Fuel cell-based vehicles most commonly combine hydrogen and oxygen to produce electricity to power the electric motor on board. Since fuel cell vehicles use electricity to run, they are considered electric vehicles.

Inside each individual fuel cell, hydrogen is drawn from an onboard pressurised tank and made to react with a catalyst, usually made from platinum. As the hydrogen passes through the catalyst, it is stripped of its electrons, which are forced to move along an external circuit, producing an electrical current. This current is used by the electric motor to power the vehicle, with the only by-product being water vapour.

Hydrogen fuel cell cars have a near zero carbon footprint. Hydrogen is about two to three times as efficient as burning petrol, because an electric chemical reaction is much more efficient than combustion.

Source: IE