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Journalism of Courage
For millennia, humans looked up to the Sun in awe, worshipping it as the giver of light and life. Ancient cultures built temples, calendars, and stories around its steady rise and fall. Only in the 20th century did physicists discover its true engine: a vast furnace of hydrogen, fusing atomic nuclei at extreme pressures and temperatures.
The Sun behaves like a giant nuclear-fusion reactor, Hans Bethe described in his Nobel presentation, converting mass into energy at its core. Now, humanity is attempting a mirror trick — not to fuse hydrogen under stellar pressures, but to use it as fuel here on Earth. We’re trying to take what powers stars and turn it into something that can power cars, homes, and industries.
Hydrogen is appealing because it burns cleanly: when combined with oxygen in a fuel cell, it produces electricity and releases only water vapor as exhaust. Unlike batteries, which must be recharged, hydrogen can be refueled quickly — much like petrol or diesel — making it attractive for long-haul trucks, buses, ships, and potentially even planes.
And hydrogen isn’t just about cars. Properly harnessed, it could power homes, balance electricity grids, and store renewable energy from solar and wind farms for months at a time, smoothing out supply when the sun isn’t shining and the wind isn’t blowing. In principle, it could provide a backbone for a carbon-free society.
For all its promise, hydrogen comes with headaches. The biggest is its low density. At room temperature, one kilogram of hydrogen would fill about 11 cubic meters — the size of a small bedroom. Petrol, by contrast, packs the same mass into just over a liter. This means hydrogen must be:
🖈Compressed to high pressures (up to 700 bar),
🖈Liquefied at cryogenic temperatures (–253 °C),
🖈Or absorbed onto advanced nano-materials like metal hydrides or porous carbons that act like sponges.
Compressed gas tanks are what current hydrogen vehicles use, but future trucks and buses may adopt nano-surface storage systems, which could make hydrogen easier and safer to handle.
Hydrogen stands out because, when it reacts — either by burning in oxygen or through fuel cells — it releases far more energy per kilogram than petrol or diesel. In fact, these reactions yield almost three times as much usable energy per unit of weight compared to conventional fuels. That’s why hydrogen was so valuable for rockets like Saturn V, where every kilogram mattered.
🖈Hydrogen (H₂): ~120 MJ/kg
🖈Petrol: ~44 MJ/kg
That means hydrogen carries nearly three times more energy by mass. The drawback is that hydrogen is the lightest element, so while it packs great energy for its weight, it takes up a lot of space. By volume, hydrogen poses a challenge: a kilogram (uncompressed) occupies 11 cubic meters, while petrol fits in just over a liter. So, compared to petrol, it is energy-rich by mass and energy-sparse by volume.
This tension is central to hydrogen’s engineering problems. To make it practical, it must be stored at high pressures, at extremely low temperatures as liquid hydrogen, or absorbed onto special materials.
One subtle but important difference between hydrogen fuel and electric batteries is how vehicle weight changes during a trip. A lithium-ion EV battery weighs the same whether fully charged or nearly empty — the car always carries that heavy load, increasing rolling resistance and reducing efficiency.
By contrast, hydrogen is consumed during the journey, so the vehicle’s weight gradually decreases. Combine this with hydrogen’s superior energy density by mass, and hydrogen-powered heavy transport (trucks, buses) may enjoy lower frictional losses and longer ranges in some contexts.
Hydrogen could do much more than power vehicles. Some of its potential uses:
🚀Heating and cooking: Hydrogen can be blended into natural gas pipelines or used directly in boilers and stoves designed for it.
🚀Backup and off-grid power: Fuel cells can deliver reliable electricity to hospitals, data centers, remote communities.
🚀Seasonal energy storage: Hydrogen produced from surplus solar or wind energy in summer can be stored and used in winter.
🚀Industrial processes: Steel production, cement, ammonia/fertilizer synthesis — all heavy-carbon industries that currently burn coal/natural gas — can be decarbonised by switching to hydrogen.
This broader scope shows why hydrogen is seen not just as an alternative to EVs, but as a pillar in the broader clean-energy economy.
Hydrogen’s story as a fuel is long and dramatic. Its first widespread use was not in cars or rockets but in the skies, as a lifting gas for the airships of the 19th and early 20th-century. Hydrogen’s low density made it perfect for buoyancy, but it was also dangerously flammable.
The most infamous reminder came in 1937, when the German airship Hindenburg burst into flames while docking in New Jersey. Although later studies suggested the airship’s skin coating contributed more to the fire than the hydrogen itself, the disaster seared hydrogen into the public imagination as something risky.
After the Hindenburg, hydrogen’s use as a transport fuel largely disappeared, surviving mainly in industrial applications like fertilizer production and refining. It would take decades before it re-emerged as an energy carrier of global importance. The Cold War space race provided the stage: engineers searching for fuels with the highest energy-to-weight ratio turned again to liquid hydrogen.
During the Apollo missions, NASA relied on hydrogen both to power the mighty Saturn V rockets and to run the spacecraft’s fuel cells. Astronauts even drank the water those fuel cells produced.
If hydrogen could take us to the Moon, its advocates argue, it can also help us build a sustainable energy future back home.
🇯🇵Japan has made hydrogen a national priority. It runs hydrogen buses and is pushing hydrogen supply chains and “hydrogen towns.”
🇪🇺Europe is rolling out hydrogen strategies across countries like Germany, France, and the Netherlands. The European Union has declared hydrogen central to decarbonization.
🇨🇳China is investing heavily in hydrogen production, fuel-cell vehicles, and pilot projects to integrate hydrogen with its renewables.
🇺🇸United States is boosting funding for hydrogen hubs, green hydrogen research, and deploying hydrogen infrastructure in California, Texas, and other energy states.
🇮🇳India has launched the National Green Hydrogen Mission, aiming to scale up hydrogen production, create demand, and build storage/fueling systems.
Each region is at a different stage: some are deploying networks, others are still in pilot phases. But everywhere, the energy transition is driving hydrogen from laboratory curiosity toward infrastructure ambition.
Hydrogen has the potential to beat EVs in specific niches — heavy transport, shipping, industrial energy storage — while EVs will likely dominate personal cars. The future energy mix may not be batteries or hydrogen, but batteries and hydrogen, each serving its best use.
But hydrogen still needs three major breakthroughs:
🪴Lower-cost green hydrogen produced via renewable-powered electrolysis
🪴Scalable hydrogen infrastructure, with pipelines, fueling stations, and storage
🪴Public and regulatory support, to reduce barriers and reassure about safety
The hydrogen revolution is still young. But once key pieces fall into place,hydrogen could do more than fuel cars; it could power the grids, heat our homes, support industries, and redefine how society runs on energy.
Shravan Hanasoge is an astrophysicist at the Tata Institute of Fundamental Research.
