Is hydrogen a realistic fuel?
For some uses yes, for others almost certainly not — and the debate is confused by treating hydrogen as a single proposition when its viability differs enormously by application.
Why it is attractive. Burning hydrogen or using it in a fuel cell produces water rather than CO₂. It is energy-dense by weight, and it can be stored, which addresses the intermittency problem electricity has.
The colours, which matter more than anything else:
Grey hydrogen — produced from natural gas by steam methane reforming, releasing CO₂. This is the overwhelming majority of hydrogen produced today, and it is not a climate solution at all.
Blue hydrogen — the same process with carbon capture. Better, and dependent on capture rates that are frequently lower in practice than claimed, plus methane leakage upstream, which some analyses argue can make it worse than burning gas directly.
Green hydrogen — electrolysis of water using renewable electricity. This is the genuinely low-carbon version, and it is currently a small fraction of production and considerably more expensive.
The fundamental problem: round-trip efficiency. Making hydrogen from electricity, compressing or liquefying it, transporting it, and converting it back loses a great deal at each stage. Using electricity directly is typically two to three times more efficient than routing it through hydrogen.
This is why hydrogen loses wherever direct electrification is possible.
Where hydrogen makes little sense:
Cars. Battery electric vehicles are far more efficient, the charging infrastructure exists, and hydrogen refuelling networks have largely failed to develop.
Home heating. Heat pumps deliver several units of heat per unit of electricity; hydrogen boilers would consume far more energy for the same heat. Independent analyses have been consistently sceptical, and several proposed hydrogen heating trials have been abandoned.
Where it has a genuine case:
Industrial feedstock — fertiliser production and steelmaking, where hydrogen replaces fossil inputs chemically rather than as fuel. This is the strongest case.
Shipping and aviation, via derived fuels.
Long-duration storage and heavy industrial heat.