Illustrative worked example. The inputs are assumptions, not a customer project. The arithmetic is real.
The scenario
An industrial site plans a 100 Nm³/h hydrogen plant at 99.999% purity, powered by solar and grid electricity.
What 100 Nm³/h means
| Quantity | Value |
|---|---|
| Hydrogen per hour | About 9.0 kg |
| Hydrogen per day (24 h) | About 216 kg |
| Water per hour | At least about 81 litres |
| Stack power | About 0.43 MW if the 70% efficiency is on a lower heating value basis, about 0.51 MW on a higher heating value basis |
The power line uses Eldtek's stated AEM stack efficiency above 70%. Hydrogen holds 33.3 kWh/kg (lower heating value) or 39.4 kWh/kg (higher heating value), so 9 kg/h at 70% needs about 428 or 506 kWh each hour. Whole-plant power is higher because compression, drying and water treatment add load.
Choosing between AEM and PEM
- AEM. Stack efficiency above 70% and operating pressure up to 35 bar. Stack life is confirmed for each project.
- PEM. Suited to rapid load-following, which matters if solar output swings a lot.
- Complete system. Eldtek's turnkey systems span 10 to over 1,000 Nm³/h and include the balance of plant.
What Eldtek confirms
- The efficiency basis and whole-plant power.
- Delivery pressure and storage.
- How the plant follows the solar profile.
- Water quality and supply.
See the hydrogen generation plants page for the full range.
Frequently asked questions
How many kilograms of hydrogen is 100 Nm³/h?
About 9.0 kg per hour, or roughly 216 kg per day, at a density of 0.0899 kg/Nm³.
How much water does a 100 Nm³/h plant need?
At least about 81 litres per hour, which is 9 litres per kilogram of hydrogen. A real plant needs a reliable treated-water supply.