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With a rising energy demand, traditional diesel generators often fill in the gap where power isn’t available. With the world’s ambition to switch to clean energy, mobile batteries are now taking the stage. 

However, batteries must be charged. If a grid connection is not available and the demand is too high for solar panels, hydrogen combustion generators and fuel cells offer a sustainable alternative, providing clean, silent, and efficient energy solutions for various applications. 

In this article, we’ll explore the differences between these two systems, since we appreciate this technology to be new and complex to understand. We’ll also delve into their benefits, and when it’s best to use them in combination with batteries. 

Hydrogen combustion generators and fuel cells are both mobile energy systems that run on (renewable) hydrogen fuel. However, they differ in their operating principles and energy conversion processes. 

Hydrogen combustion generators burn hydrogen

A hydrogen combustion generator, a.k.a. hydrogen piston engine or hydrogen ICE, is like a diesel generator as it has a combustion engine. This means that it is converting hydrogen fuel into electrical energy through a combustion process. It typically consists of a hydrogen storage tank, an engine, and a generator. The hydrogen fuel is combusted in the cylinders of the engine, resulting in rotational force which is converted to electricity in the generator.

When using green hydrogen, there are no CO2 emissions involved. One challenge, however, is the presence of NOx emissions. Despite them being lower, it does mean this solution is not suitable for zero-emission construction projects in Natura 2000 areas. 

Hydrogen fuel cells use membranes

A hydrogen fuel cell, on the other hand, is a system that converts the chemical energy of hydrogen directly into electrical energy and heat. Unlike hydrogen generators, fuel cells do not produce electricity through combustion or an intermediary conversion process. Instead, they rely on an electrochemical reaction between hydrogen and oxygen using membrane electrodes, which produces hot water vapor as the only byproduct. The challenge with fuel cells is the sensitivity of the membranes in the fuel cells, which require a high quality of hydrogen and a constant load.  

Watermeln H2 genset, 200 kw based on fuel cells

Through Skoon’s Marketplace, you can easily find and book a hydrogen generator that not only meets your technical specifications but also aligns with environmental responsibilities. 

Remember, the right preparation and understanding of your power needs lead to more successful and compliant project execution.

Benefits of hydrogen-powered systems

Both hydrogen generators and fuel cells offer numerous advantages over conventional diesel generators, making them an attractive choice to charge batteries on site. Many applications, such as facility management and construction sites, can switch to future proof power. A number of advantages, especially relevant for fuel cells: 

  1. Zero Emissions: One of the most significant benefits of hydrogen-powered systems is their zero-emission operation, or low emissions in the case of a combustion generator. Unlike diesel generators, which release harmful pollutants, hydrogen fuel cells and fuel cells produce only water vapor as a byproduct.  
  1. Silent Operation: Hydrogen fuel cells systems operate silently, eliminating the noise pollution associated with combustion generators. This feature makes them ideal for use in residential areas, film sets, outdoor events, construction sites, and other noise-sensitive environments. 
  1. Mobility and Off-Grid Capability: Both hydrogen generators and fuel cells are highly mobile and can be easily transported to remote or off-grid locations. This makes them suitable for powering temporary or mobile applications, such as construction sites, emergency response operations, and remote communities without access to traditional power grids. A small caveat we need to make here is that the off-grid location should be accessible for hydrogen refueling, often performed through the delivery of high pressure tubes filled with hydrogen. 
  1. Sustainable Fuel Source: Hydrogen is a renewable fuel that can be produced from various sources, including water electrolysis using renewable energy sources like solar or wind power. This makes hydrogen-powered systems a sustainable and environmentally friendly energy solution, reducing dependence on fossil fuels and contributing to a greener future. 

Pairing a mobile battery with a hydrogen fuel cell brings further benefits as the use of hydrogen fuel is minimized and peaks in energy demands are delivered through the battery.   

When and when not to use hydrogen generators and fuel cells

Hydrogen generators and fuel cells have distinct advantages and are suitable for different applications based on factors such as energy density, runtime, and cost considerations. 

Hydrogen generators are ideal for applications that require a reliable and continuous supply of electricity for extended periods, such as construction sites or outdoor events. They can provide power for several days or weeks, depending on the size of the hydrogen storage tank and the power demand. 

Fuel cells are well-suited for applications that require a constant and uninterrupted power supply, such as backup power systems for facilities or critical infrastructure. They can provide a steady flow of electricity quietly and without emissions, as long as hydrogen and oxygen are supplied. That makes them a reliable and efficient option for extended runtime requirements. 

Costs of hydrogen-powered systems

The initial investment in hydrogen-powered systems can be higher than diesel generators. However, on the long-term operational costs and environmental benefits make them an attractive choice for a growing number of applications

Rental Costs

The rental cost of hydrogen generators and fuel cells can vary depending on the power output, runtime requirements, and location. Typically, the rental cost ranges from €1.000 per week for a 150 kVA hydrogen combustion generator to €3.500 per week for a 200 kVA fuel cell system. 

Fuel Costs

The cost of hydrogen fuel is a significant factor in the overall operating costs of hydrogen-powered systems. This is why customers use Skoon’s Decision Tool to forecast the fuel consumption and costs. Hydrogen costs can range from 5 EUR to 20 EUR (excluding storage and transport) per kilogram, depending on the production method and location. However, as hydrogen production technologies advance and become more widespread, the cost of hydrogen is expected to decrease. 


The runtime of a hydrogen generator or fuel cell depends on the size of the hydrogen storage tank and the power demand. Combined with a mobile battery, typical hydrogen bundles can provide enough fuel for several days or weeks of continuous operation. This ofcourse is depending on the system’s capacity and load requirements. 


Hydrogen generators and fuel cells offer a clean, silent, and mobile energy solution for charging mobile batteries in multiple applications, including film sets and construction sites. While they differ in their operating principles, both systems provide a (close to) zero-emission power and offer numerous advantages over traditional diesel generators.


To find the right energy system, visit Skoon Energy’s marketplace . With over 260 different types of energy systems across Europe, you are sure to find the best one for your temporary project. 

Our energy experts are always happy to help you choose the ideal hydrogen generator or fuel cell solution, ensuring reliable, clean, and efficient power for your project or facility.  

That’s our mission. Clean energy, always. 

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    1. What is the primary difference between hydrogen combustion generators and hydrogen fuel cells? 

    Hydrogen combustion generators use a combustion engine to convert hydrogen into electricity, similar to a diesel generator. Hydrogen fuel cells, on the other hand, convert hydrogen directly into electricity through an electrochemical reaction without combustion. 

    1. What are the main benefits of using hydrogen-powered systems? 

    Hydrogen-powered systems offer zero or low emissions, silent operation, mobility, off-grid capability, and the use of a renewable fuel source. 

    1. Why are hydrogen fuel cells considered better for noise-sensitive environments? 

    They operate silently, making them ideal for residential areas, film sets, outdoor events, and other places where noise reduction is important. 

    1. In what scenarios are hydrogen combustion generators most suitable? 

    Hydrogen combustion generators are ideal for applications requiring a reliable and continuous power supply for extended periods. Benefiting the most are construction sites or outdoor events. 

    1. What are the environmental benefits of hydrogen fuel cells compared to diesel generators? 

    Hydrogen fuel cells produce only water vapor as a byproduct. Diesel generators on the other hand emit harmful pollutants such as nitrogen oxides, particulate matter, and carbon monoxide. 

    1. Can hydrogen-powered systems be used in off-grid locations? 

    Yes, both hydrogen generators and fuel cells can be used in remote or off-grid locations. However, the location must be accessible for hydrogen refueling. 

    1. What factors affect the rental costs of hydrogen generators and fuel cells? 

    Rental costs vary depending on the power output, runtime requirements, and location. For example, a 150 kVA hydrogen combustion generator can cost around €1,000 per week. A 200 kVA fuel cell system can cost up to €3,500 per week. 

    1. What is a significant challenge associated with hydrogen fuel cells? 

    Hydrogen fuel cells require high-quality hydrogen and a constant load due to the sensitivity of the membranes in the cells. 

    1. How does the cost of hydrogen fuel affect the overall operating costs of hydrogen-powered systems? 

    Hydrogen fuel costs can significantly impact operating costs. These are ranging from 5 EUR to 20 EUR per kilogram depending on production methods and location. As production technologies advance, these costs are expected to decrease. 

    1. When should hydrogen-powered systems be avoided? 

    Hydrogen-powered systems may not be the best solution when cheaper options like a small grid connection, solar panels, or a diesel generator running on HVO are available. This is particularly due to the current high costs of green hydrogen.