Pure Water | Green Hydrogen
The water for your electrolyzer can come from the air over the site.
Inland hydrogen projects tend to get stuck on water long before they get stuck on power. The WaHa Vaporator® makes distilled-grade water from desert air at the point of use, so production can sit where the hydrogen is used, without a pipeline or a withdrawal permit.
The WaHa Vaporator® generates distilled-grade water from ambient air at the site of a green hydrogen project, supplying feedwater for electrolysis without a pipeline, a surface or groundwater withdrawal permit, or trucked deliveries. The system operates in humidity as low as 10% RH, which allows electrolysis to be located at remote, inland renewable energy sites where a conventional water supply is unavailable or slow to permit.
The problem
At an inland site, water is usually the slowest thing to arrange
Electrolysis consumes about 9 liters of water for every kilogram of hydrogen it makes, according to RMI's 2023 analysis of green hydrogen water use. That's a modest volume. The trouble is where it's needed. The best solar and wind resources tend to sit in dry, remote country, and a study published in Communications Sustainability in June 2026 found that nearly half of all announced large-scale electrolysis projects are in arid or water-stressed regions.
So an inland project has to move something. It can build a desalination intake on the coast and pipe the water in, which means permits, right-of-way and a long build before the first liter arrives. It can truck water in and pay more for every kilometer between the fill point and the site. Or it can move the electrolyzer to the coast and ship the hydrogen back out, which makes little sense when the hydrogen was meant to be used where it's made.
How it works
How do you supply an electrolyzer with water at a site that has none?
You make it from the air that's already there. The WaHa Vaporator® is a sealed thermodynamic engine paired with a desiccant wheel that's matched to the site's humidity profile. The desiccant is a MOF, and the platform is built on the MOF chemistry awarded the 2025 Nobel Prize in Chemistry. It pulls water vapor out of the ambient air and condenses it in a sealed chamber, isolated from the ambient air stream, so what comes out is distilled-grade water.
Two things make that useful for electrolysis. Desert air is dry, and most atmospheric water systems stop producing well before the air gets that dry, while the WaHa Vaporator® holds its rated output down to 1 gram of water per kilogram of air. And because the water starts out distilled-grade, the polishing step in front of the electrolyzer has far less to remove than it would from brackish groundwater or seawater.
Nothing is drawn from the ground or a river, so there's no withdrawal permit to apply for. The system runs on site power, the same renewable supply that runs the electrolyzer.
The economics
Where the water comes from decides what it costs
Trucked water gets more expensive with every kilometer from the fill point, and a pipeline carries its cost across every kilometer it runs. Water made from air on site costs the same next to a river as it does deep in the desert.
On the coast, or next to a cheap municipal supply, that's no advantage at all, and we'll tell you so. It pays off inland and off the grid, far from a reliable source.
No withdrawal permit
The water comes from the air, so there's no surface or groundwater draw to license and no local water users to compete with.
No pipeline to build
There's no intake, no right-of-way and no multi-year construction schedule standing between the project and its first water.
Distance drops out
The cost per liter depends on the machine and its power supply. How far the site sits from the nearest river or coastline doesn't enter into it.
A bridge to permanent supply
If a pipeline is planned for later, WaHa can supply water while it's permitted and built, then step aside when it arrives.
Adoption
Start with one site and one number
Every inland project has a water plan, even if it's a line in a spreadsheet that says "truck it in for now." The useful first step is to put that plan next to water made on site, using the real climate at your location.
Send us the site coordinates, the electrolyzer size and your current water plan. We'll run a site evaluation from the location's climate data, and where the numbers hold up, set up a pilot test so you can see logged output at your own site before committing to a full installation.
Where it applies
Where on-site water fits in hydrogen
Remote mines
Mines moving off diesel with hydrogen made on site, often far from any reliable water source.
Off-grid power units
Hydrogen power units that currently run on fuel trucked in from a central plant. Make the hydrogen on site and the fuel run goes away.
Production at the renewable resource
Projects that put the electrolyzer beside the solar or wind farm, where the site has plenty of power and no water.
Remote industrial users
Facilities in dry regions that make hydrogen for their own process use and can't get a water allocation.
Projects waiting on a pipeline
Sites where a desalination pipeline is planned but years away. On-site water lets production start now.
Electrolyzer makers and integrators
Suppliers of containerized and modular electrolyzers whose customers keep asking where the feedwater will come from.
What the platform has shown in the field
Our technology is protected in depth: explore the WaHa patent portfolio.
Questions operators ask
Green Hydrogen FAQ
How much water does green hydrogen production need?
Electrolysis consumes about 9 liters of water per kilogram of hydrogen, according to RMI's 2023 analysis. Purification and cooling add to that, and at plants with evaporative cooling, cooling can be the largest share. The WaHa Vaporator® supplies the feedwater the electrolyzer splits, and we'll work out the volume for your electrolyzer during a site evaluation.
Can an atmospheric water generator work in the desert?
Most can't. Compressor-based systems need humid air before they condense much of anything. The WaHa Vaporator® uses a desiccant wheel with a sealed thermodynamic engine, works in humidity as low as 10% RH, and holds rated output down to 1 gram of water per kilogram of air. At the utility standard it covers 83.4% of the world's water-stressed land, against 1.0% for compressor-based AWG. See where it works.
Is water from air pure enough for an electrolyzer?
It's a very good starting point. The WaHa Vaporator® produces distilled-grade water with no PFAS, no microplastics, no heavy metals, no VOCs and no bacteria, independently tested against US EPA, UAE.S 149, and GSO 149 drinking water standards. Electrolyzers still run their own final polishing to their feed spec, and that step has far less to remove from distilled-grade water than from groundwater or seawater.
Does WaHa make sense for a coastal hydrogen plant?
Usually not. On the coast, seawater desalination is cheap and well understood, and water is a small part of the plant's cost. WaHa is for sites a pipeline can't reach quickly: inland, off the grid, or both.
Do we need a water permit to use WaHa?
You won't need a withdrawal permit for the water itself, since nothing is drawn from surface water or groundwater. The usual permits for siting and installing equipment still apply.
Pure Water. Inexpensive Dry Air. Anywhere.
Tell us where your electrolyzer will sit. We'll size the water for that site.
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