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Global land and water limits to electrolytic hydrogen production using wind and solar resources

Davide Tonelli, Lorenzo Rosa, Paolo Gabrielli, Ken Caldeira, Alessandro Parente, and Francesco Contino · Nature Communications 14, 5532 · 2023

Key finding. Setting a country-by-country 2050 hydrogen demand against national land and water availability, less than 50% of that demand could be met by local production without land or water scarcity — the exact share depending on how much land is allocated to solar panels or wind turbines.

Six world maps in two rows and three columns, categorising each country as having no scarcity in green, land scarcity in yellow, water scarcity in blue, or both in red, from producing its projected 2050 hydrogen demand. The top row assumes solar and the bottom wind, and the columns assume 100%, 10% and 5% of suitable land is available. At 100% coverage most countries are green; by 5% much of Europe, South and East Asia turns yellow or red.
How much of a country turns red depends less on its hydrogen demand than on how much land it is willing to give over. Africa, South America, Canada and Australia stay green across every column — which is what makes them the likely hydrogen exporters — while Europe and South Asia run into land and water limits as soon as the land allocation is realistic. Figure 6 from Tonelli et al. (2023), Nature Communications 14, 5532. Reproduced under CC BY 4.0. Extracted from the published PDF and resized for web display.

What question did this research address?

Net-zero plans lean on a large scale-up of electrolytic hydrogen. Making it takes electricity, which takes land for panels and turbines, and it takes freshwater as feedstock — both of which are already contested in many countries.

This paper asked which countries could actually produce their own hydrogen within their own land and water endowments, and which would have to import.

What did we find?

A reference scenario for 2050 hydrogen demand is built country by country, then compared against each country's land and water availability rather than against a global total.

The headline share is sensitive to a policy choice, not just to geography: how much land a country is willing to allocate to solar or wind determines how much of its hydrogen it can make at home.

The analysis identifies which countries are constrained by their own natural resources from reaching electrolytic hydrogen self-sufficiency under a net-zero target.

Land and water abundance marks out the likely exporters — Southern and Central-East Africa, West Africa, South America, Canada and Australia.

The same result can be read as trade in industry rather than in hydrogen. A country short of land and water can import the hydrogen, or it can export the industries that would have consumed it.

Why does it matter?

It converts hydrogen from an energy question into a land and water question. Electrolysis is usually costed in dollars per kilogram; this shows the binding constraint for many countries is physical endowment, which no cost reduction relieves.

The "import hydrogen or export the industry" framing is the consequential one. It means the geography of heavy industry is at stake in how the hydrogen economy is built, not merely the geography of fuel supply.

It also names a new set of resource exporters that does not map onto today's energy exporters, which has the same strategic implications as the shift from fuels to materials.

Citation

Davide Tonelli, Lorenzo Rosa, Paolo Gabrielli, Ken Caldeira, Alessandro Parente, and Francesco Contino (2023). Global land and water limits to electrolytic hydrogen production using wind and solar resources. Nature Communications 14, 5532.

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