Hydrogen is the most energy-dense fuel in existence. One kilogram stores three times more energy than one kilogram of gasoline. It produces only water when used. It can be made from renewable electricity with zero carbon. There is one problem that has prevented it from becoming the dominant energy carrier of the 21st century: storing it is extraordinarily difficult. Solve that problem — and hydrogen becomes the fuel of the century. This letter is about the four technologies tackling it, the private capital building them, and whether hydrogen is genuinely going to stick.
Not investment advice. Data sourced from IEA Global Hydrogen Review 2025, PatSnap Innovation Intelligence, Hydrogenious LOHC Technologies, Amogy, H2SITE, Natron Energy, and market research through June 2026. All figures current as of June 2026.
Hydrogen's physical properties make it simultaneously extraordinary and exasperating. It is the lightest element in the universe. This is the source of its extraordinary energy density by weight — one kilogram of hydrogen contains 120 MJ of energy, versus 44 MJ for a kilogram of gasoline. But lightness is also the problem. Hydrogen gas is so diffuse that storing meaningful quantities at ambient pressure requires impractically large volumes. One kilogram of hydrogen at atmospheric pressure and room temperature occupies approximately 11,000 litres — a room-sized volume for what fits in a small fuel tank when compressed or liquefied.
There are three ways to force hydrogen into a manageable volume, each with significant drawbacks:
Compress it to 350–700 bar (5,000–10,000 psi). This requires heavy, expensive composite pressure vessels and consumes approximately 10–15% of the hydrogen's energy content in the compression process. The tanks can fail. The infrastructure requires special materials — hydrogen embrittles ordinary steel over time. Refuelling stations require high-pressure equipment that costs $1–3 million each. Compressed hydrogen has been the dominant storage method for fuel cell vehicles, and it works — Toyota's Mirai and Hyundai's NEXO use it — but the infrastructure cost is the primary reason hydrogen fuelling networks have not scaled like EV charging networks.
Liquefy it by cooling to -253°C (just 20 degrees above absolute zero). Liquid hydrogen has high volumetric density — similar to compressed hydrogen but in a less pressurised vessel. The problem: liquefaction consumes 25–35% of the hydrogen's energy content. And liquid hydrogen "boils off" — it gradually evaporates from even the best-insulated tanks, losing 0.1–0.5% per day. Over a two-week period at sea, a tanker can lose 2–5% of its cargo to boil-off. For transport and large-scale storage, this is an acceptable loss. For passenger vehicles parked in a garage for a week, it creates a safety hazard.
Store it chemically — binding hydrogen atoms to a carrier molecule that is stable at ambient conditions, then releasing them on demand. This is the frontier where the most interesting investment is happening. Chemical carriers solve the pressure and temperature problems simultaneously — they can be stored and transported as ordinary liquids using existing infrastructure. The challenge: releasing the hydrogen from the carrier molecule requires energy and time.
The hydrogen storage problem is not a physics problem — the physics is well understood. It is an engineering and economics problem. The question is which solution reaches acceptable cost and convenience fastest. The winner determines who wins the hydrogen economy.
The incumbent technology. High-pressure compressed tanks (700 bar for vehicles, 350 bar for industrial) are the current standard for fuel cell vehicles and small-scale industrial hydrogen use. Liquid hydrogen is the preferred method for large-volume transport — space launches, liquid hydrogen tankers, and increasingly, long-distance shipping.
Air Liquide has developed liquid hydrogen tanks with boil-off rates reduced to less than 0.25% per day — a dramatic improvement from earlier designs. Lightweight carbon-fibre composite tanks can now store 700-bar hydrogen safely enough for consumer vehicles. Toyota's Mirai, Hyundai's NEXO, and the growing fleet of hydrogen fuel cell trucks and buses use compressed tanks — demonstrating that the technology works at consumer scale.
The bottleneck is infrastructure cost. A single hydrogen refuelling station costs $1–3 million versus $50,000–150,000 for a fast EV charger. The compressed hydrogen infrastructure economics are the primary reason hydrogen fuel cell vehicles have not scaled faster — not the vehicles themselves, but the distribution network they require.
The most promising near-term solution for long-distance hydrogen transport. LOHC systems bind hydrogen atoms to an organic carrier molecule — typically dibenzyltoluene (DBT), which is an ordinary heat transfer oil used in industrial processes — creating a hydrogen-rich liquid that can be stored and transported at ambient temperature and pressure using existing tanker infrastructure.
The process: hydrogen is "loaded" onto the carrier molecule (hydrogenation) at the production site. The LOHC liquid is then shipped exactly like diesel or crude oil — using the same tankers, ports, and storage facilities. At the destination, hydrogen is released (dehydrogenation) by heating the liquid to 150–300°C. The carrier molecule is then shipped back for reloading. The carrier is not consumed — it cycles indefinitely.
Hydrogenious LOHC Technologies (Germany) is the world leader. It has deployed the first full LOHC-based hydrogen mobility chain including pilot refuelling stations in Germany. In 2025 it raised €17 million (backed by Temasek, Anglo Platinum, Chevron Technology Ventures, and Covestro) and is integrating LOHC with solid oxide fuel cells for hospital-scale power generation. The key advantage of LOHC: it requires no new infrastructure for transport. Every existing oil tanker, pipeline, and storage depot can carry LOHC immediately. The key disadvantage: the dehydrogenation process requires significant heat input, which consumes energy and adds system complexity.
Ammonia (NH₃) stores 17.6% hydrogen by weight and achieves 108 kg H₂/m³ volumetric density as a liquid — 2.7× higher than 700-bar compressed hydrogen. It has a global supply chain already in place: 200 million tonnes of ammonia are produced and transported annually for fertiliser use, with established ports, storage tanks, and shipping routes on every continent. The idea: produce green ammonia at renewable energy sites (using green hydrogen and atmospheric nitrogen), ship it using existing infrastructure, then "crack" it back to hydrogen at the destination.
Amogy (MIT spinout, backed by Amazon, Aramco Ventures, AP Ventures, Breakthrough Energy Ventures) is the leader in ammonia-to-power systems for heavy industry and maritime applications. In 2026, Amogy began commercial deployment — assembling the first modules to ship to pilot customers in commercial operational settings. Critically, green ammonia from India and China is now only 10–20% more expensive than conventional grey ammonia — a dramatic cost compression from 2–3× more expensive just 24 months ago.
H2SITE (Spain, backed by Breakthrough Energy Ventures, Hy24, Equinor Ventures) raised €36 million in January 2025 for its membrane reactor technology that enables efficient ammonia cracking at multi-tonne per day scale — addressing the dehydrogenation bottleneck. The IEA validated industrial-scale ammonia cracking as a milestone technology in 2025. First maiden voyages of ammonia-fuelled vessels with onboard cracking have occurred — the maritime hydrogen economy is real.
The most elegant solution — and the hardest to commercialise. Metal hydrides store hydrogen by chemically bonding it within a solid lattice of metal atoms (typically magnesium, titanium, or rare earth alloys). The hydrogen is released by heating. Storage occurs at low pressure and ambient temperature, with volumetric density exceeding compressed gas. The safety profile is exceptional — there is no pressurised gas to leak or explode.
61,987 active patents cover metal hydride storage as of 2026 — by far the most patent-intensive hydrogen storage technology. China leads with over 60% of metal hydride filings. Japan and South Korea have commercialised metal hydride storage for niche applications including forklift fuel cells and stationary backup power. The global solid-state hydrogen storage market was $1.6 billion in 2025 and is projected to reach $8.4 billion by 2034 at 17.8% CAGR.
The barriers: metal hydrides are heavy (adding significant weight to vehicles), release hydrogen slowly (limiting power output for dynamic applications), and require heat for release that must come from somewhere in the system. Metal-organic frameworks (MOFs) offer ultra-high surface areas for hydrogen adsorption but currently require cryogenic temperatures. Immaterial (University of Cambridge spinout) is developing advanced nanomaterials to solve the MOF temperature problem. PowiDian (France, founded by an ex-Airbus researcher) focuses on solid-state hydrogen storage power stations for stationary applications where weight and speed constraints are less critical. The applications where solid-state wins today: stationary backup power, forklifts, submarines, cold climate storage. The applications where it wins tomorrow: onboard vehicle storage if weight and kinetics improve sufficiently.
India deserves its own section in any serious hydrogen letter — and it was missing from the first draft. That omission is now corrected. India is not a footnote in the global hydrogen story. It is one of the three most consequential hydrogen markets in the world, alongside China and the European Union — and it is moving faster than most Western analysts are tracking.
On August 13, 2025, India unveiled its first indigenously developed hydrogen train — a 10-coach, 1,200 kW hydrogen fuel cell trainset approved for the Jind–Sonipat section of Northern Railway in Haryana. The fuel cell systems were provided by Tata Advanced Systems. The hydrogen storage and refuelling facility at Jind was established with PESO (Petroleum and Explosives Safety Organisation) approval — India's first indigenous hydrogen train infrastructure. The train produces only water vapour as emission. It is designed to carry 2,500 passengers and operates at up to 75–150 km/h depending on the corridor. The Ministry of Railways has allocated approximately ₹2,800 crore for hydrogen train projects covering train development, hydrogen infrastructure, production, storage, and refuelling. Plans exist to deploy up to 35 hydrogen trains across heritage, regional, and non-electrified corridors where electrification is challenging or prohibitively expensive.
The train is the symbol. The mission is the substance. India's National Green Hydrogen Mission (launched 2023) targets 5 million tonnes of green hydrogen production per year by 2030 — requiring 125 GW of new renewable capacity to feed the electrolysers. The government has committed subsidies of approximately ₹8 lakh crore and is targeting a production cost of $1.5/kg by 2030. At that price point, green hydrogen becomes cost-competitive with grey hydrogen (produced from natural gas) in most applications. India's position is structurally advantageous: some of the cheapest solar electricity in the world, a vast domestic market for green hydrogen in steel, fertilisers, and transport, and the Faradion/Reliance Jamnagar gigafactory building indigenous sodium-ion and hydrogen storage capacity simultaneously.
India's NTPC has introduced hydrogen fuel cell buses at 11,500 feet altitude in Leh — demonstrating hydrogen's performance in extreme cold conditions that battery EVs struggle with. Kochi and Visakhapatnam ports are being developed as hydrogen bunkering hubs for maritime decarbonisation. India is not watching the hydrogen economy. It is building one.
The storage infrastructure is the critical link. India's hydrogen train at Jind uses compressed hydrogen stored on-site at the dedicated refuelling facility. For the 5 million tonne per year green hydrogen mission to work, India needs storage at every scale: compressed tanks at refuelling points, large-scale geological storage for grid balancing, and LOHC or ammonia systems for long-distance transport. Faradion (acquired by Reliance) is building the Jamnagar gigafactory to serve exactly this market. The India hydrogen storage opportunity is not peripheral — it is as large as the entire current global hydrogen storage market, and it is being built from scratch by a country with the industrial ambition and the renewable energy resource to do it.
Hydrogen has been "the fuel of the future" for fifty years. The hydrogen economy has been perpetually twenty years away — a statement that echoes the old fusion energy joke. The reasons for previous disappointments are instructive: cost of green hydrogen production was too high, storage was too difficult, infrastructure investment was too large relative to demand, and the chicken-and-egg problem (no infrastructure without demand, no demand without infrastructure) was never cracked. Each of these barriers is now materially lower than at any previous point in the technology's history.
This time is different in specific, measurable ways. Green hydrogen production costs have fallen 50–60% since 2020 and are falling further as electrolyser costs decline with scale. Green ammonia from India and China is now only 10–20% more expensive than grey ammonia — down from 200–300% more expensive 24 months ago. Salt cavern storage has been validated at industrial scale. Industrial-scale ammonia cracking has been demonstrated. The IEA's 2025 Global Hydrogen Review recorded "a record number of technologies advancing in technology readiness level" across the hydrogen value chain. The technology is genuinely maturing.
The risk that remains is the policy risk. Green hydrogen economics still require either a high carbon price (making grey hydrogen expensive) or direct subsidies (making green hydrogen competitive). The US Inflation Reduction Act's $3/kg hydrogen production tax credit and the EU Hydrogen Bank's auction programme are the primary policy supports. If those policies are reversed — as the political winds in both the US and Europe have made possible — the green hydrogen investment case weakens significantly. The technology works. The economics depend on policy architecture that is not yet permanently locked in.
Long-horizon thinking on capital, technology, and the forces shaping the next decade of wealth creation. Written from first principles. Not consensus. Not noise.