Input Parameters
Results
Enter your operating conditions above and click Calculate to see detailed hydrogen production and energy results.
Example Input and Output
Example case: 50 A, 10 V, 30 minutes, 25 °C, 101.3 kPa, 80 % efficiency, one cell in operation.
| Parameter | Value | Notes |
|---|---|---|
| Current | 50 A | Typical medium-sized laboratory stack current. |
| Voltage | 10 V | Overall stack voltage including ohmic losses. |
| Time | 30 min | Electrolysis run time converted to 1800 s. |
| Hydrogen volume (actual) | ≈ 12.9 L | With 80 % efficiency at 25 °C, 101.3 kPa. |
| Energy consumption | ≈ 2.50 kWh | Calculated from current, voltage, and operating time. |
Hydrogen Electrolysis Calculator Overview
1. Role of Hydrogen in Modern Energy Systems
Hydrogen is a versatile energy carrier for industry, mobility, and storage. Electrolysis converts renewable electricity into clean hydrogen, decoupling power generation from consumption while avoiding direct emissions at the point of use.
2. Linking Charge, Moles, and Gas Volume
The calculator applies Faraday’s law to connect electric charge with the amount of substance. From total coulombs, it determines moles of hydrogen and then uses the ideal gas law to estimate gas volume under specified pressure and temperature.
3. Using Faraday’s Law of Electrolysis
Faraday’s law states that the moles of hydrogen equal total charge divided by the product of the Faraday constant and electrons required per molecule. For hydrogen, two electrons are needed, so doubling the current or time doubles the theoretical hydrogen production rate.
4. Comparing with Dedicated Electrolysis Tools
When you need more detailed time or mass planning, you can pair this tool with the Electrolysis Time & Mass (Faraday) Calculator . Together they support laboratory design, pilot plants, and coursework in electrochemistry and green hydrogen engineering.
5. Considering Gas Properties and Compressibility
Estimating hydrogen handling requirements often requires relating volume and molar quantity. For broader gas problems, link this page with the Molar Mass of Gas Calculator , which helps convert between mass, moles, and gas volumes.
6. Energy Consumption and System Efficiency
The calculator evaluates energy use from current, voltage, and time, reporting total kilowatt-hours and specific energy per normal cubic metre. By updating efficiency, users can benchmark technology options and quantify benefits of lower cell resistance or improved catalysts.
7. Practical Workflow for Engineers and Students
Start by entering realistic stack parameters and efficiency assumptions. Review gas production and specific energy consumption values, then adjust current, operating pressure, or temperature to meet project targets. Save CSV or PDF outputs to document scenarios, homework solutions, or feasibility studies in your reports.
Formula Used
The core relation is Faraday’s law: n(H₂) = I × t / (2F), where I is current, t is time, and F is the Faraday constant. Hydrogen volume is then computed using the ideal gas law V = nRT / P at your selected pressure and temperature.
Actual volume is scaled by the efficiency you provide. Energy consumption uses E = I × V × t, converted from joules to kilowatt-hours. Specific energy divides total energy by hydrogen volume at standard conditions, giving kWh per normal cubic metre.
How to Use This Calculator
First, enter stack current, cell voltage, and operating time, then specify whether the time is in seconds, minutes, or hours. Add your expected electrolyte temperature, outlet pressure, overall efficiency, and number of identical cells. Higher currents and longer runs generate more hydrogen.
Press Calculate to obtain gas production, energy use, and specific consumption figures. Adjust parameters to explore different operating strategies. Use the CSV download to archive numeric results and the PDF option when you need polished outputs for presentations or laboratory reports.
Frequently Asked Questions
1. What assumptions does this hydrogen electrolysis calculator use?
The calculator assumes ideal gas behaviour, a constant operating current, and a fixed overall efficiency. It also treats all cells as identical and uses Faraday’s law to relate charge to hydrogen production.
2. Can I use this tool for different electrolyser technologies?
Yes. You can apply it to alkaline, PEM, or solid oxide stacks. Enter appropriate voltage, efficiency, and temperature ranges for your technology to obtain representative hydrogen and energy estimates.
3. Why does actual hydrogen volume differ from theoretical volume?
Theoretical volume assumes every electron contributes perfectly to hydrogen formation. Real systems lose efficiency through side reactions, ohmic losses, and mass transport limits. The efficiency input scales the theoretical volume to a more realistic value.
4. How should I choose a realistic efficiency value?
Consult datasheets, experimental measurements, or literature for your electrolyser type and operating point. Modern systems often operate between sixty and ninety percent efficiency, depending on current density, temperature, and maintenance conditions.
5. What is the meaning of kWh per normal cubic metre?
Kilowatt-hours per normal cubic metre expresses the electrical energy required to produce hydrogen at standard conditions. Lower values indicate more efficient hydrogen generation and lower operating costs for a given production rate.
6. Can this calculator replace detailed process simulation software?
It is primarily intended for quick sizing, teaching, and preliminary feasibility checks. Detailed design still requires specialised simulation tools that include dynamic behaviour, degradation, water balance, compression stages, and safety constraints.