Why hydrogen?


The basic prerequisite for the application of hydrogen in all affected sectors is the transition to a low-emission or emission-free economy. The European Union itself has set itself the goal of achieving complete climate neutrality by 2050, i.e. capturing and storing the same amount of greenhouse gas emissions as will be released into the atmosphere.

The very fact of the development of renewable energy sources in all member states then creates space for the stabilization of their unpredictable electricity production. In this case, hydrogen will play the role of an energy carrier, which is particularly suitable for seasonal accumulation and some mobility applications.

What is hydrogen?

Hydrogen is the lightest gaseous chemical element, which makes up two-thirds of all cosmic matter. It is estimated to make up more than 30% of the total mass of the Sun. It is the third most abundant element on Earth, yet it hardly ever occurs as a single molecule because it is highly reactive and immediately forms compounds.

Hydrogen is ubiquitous, whether in the form of water, natural gas, or methanol. Being the simplest and lightest element, it disperses into the air very quickly upon release. When hydrogen leaks, it does not pollute the environment in any way. It is an emission-free substance that is non-toxic and has no odor. Hydrogen is flammable but does not support combustion, burning with a colorless flame.

What energy properties does hydrogen have?

Hydrogen is a very energy-rich fuel (33 kWh/kg) and is thus currently a direct competitor especially to battery technologies. In a direct comparison of hydrogen with batteries, today the leader in the field of battery technology is the automobile company Tesla, whose batteries reach an energy density of 250-260 Wh/kg. Read more

What is the history of hydrogen use?

Hydrogen is a gas known to the world for a long time, it was discovered in 1776 by the British scientist Henry Cavendish. Unfortunately, at the time of its discovery, hydrogen did not find wider application in industry, mainly due to the advent of cheaper fossil fuels in the 19th and 20th centuries. When you say the word "hydrogen", everyone naturally thinks of the Hindenburg airship disaster. Despite the fact that "exploding" hydrogen is still described as the culprit, the disaster was caused by an electrical discharge that ignited the highly flammable material from which the ship's hull was made. Read more


What is the use of hydrogen?

Hydrogen is a carrier (storage) of energy. It is widely used in transport, energy and industry. In the future, hydrogen is to serve as one of the energy carriers for the application of the so-called sector coupling, or the concept of sector integration. Read more

How is hydrogen produced?

96% of all hydrogen produced today comes from fossil fuels. Only 4% is produced using water electrolysis. However, this ratio should change in the next decade in favor of emission-free production using the above-mentioned electrolysis of water.

Currently, it is reported that 96% of all world hydrogen production comes from fossil fuels, mainly in the so-called steam reforming of natural gas. It is the cheapest current hydrogen production technology. Steam reforming is a chemical process in which steam with a temperature of 750-950 °C is fed to methane. Read more

How is hydrogen produced in the Slovak Republic and what is the potential for the production of green hydrogen here?

Due to its specific position in the heart of Europe, the Slovak Republic has relatively little potential for the production of so-called green hydrogen.

The coefficient of utilization (approx. slightly above 20%) of wind power plants is lower in our country than in neighboring coastal states, where strong and stable winds blow on the coasts (approx. above 30%). Currently, there is no large electrolyser in the Slovak Republic that is intended for the production of green hydrogen on a commercial basis. Read more


Electrolysis is a process in which a direct current of electricity breaks the chemical bond between hydrogen and oxygen in an aqueous solution. 

2 H2O → 2 H2 + O2

How much water is used in electrolysis?

For the production of 1 kg of hydrogen and 8 kg of oxygen, 8.92 liters of demineralized water are needed, i.e. water stripped of all present minerals (even purer than distilled water) Read more

Aké máme typy elektrolyzérov?

V súčasnosti sa hovorí najčastejšie spolu o troch typoch elektrolyzérov, ktoré sú natoľko vyspelé, aby mohli saturovať dopyt na trhu. Ide o elektrolyzéry využívajúce alkalickú elektrolýzu, PEM elektrolýzu a vysokoteplotnú elektrolýzu prebiehajúcu v palivových článkoch s pevnými oxidmi. Read more

What kind of water can be used in electrolysis?

The water required for the production of very pure hydrogen must be demineralized, i.e. free of all dissolved substances and impurities. However, it can be obtained from practically any water source. Read more




Hydrogen storage



How can hydrogen be stored?

Currently, the most promising and also the most commercially advanced technology for hydrogen storage is hydrogen compression in the gaseous state. The hydrogen stored in this way tends to escape due to the very small size of the molecule. Read more

Application of hydrogen in mobility

What are fuel cells?

Fuel cells in electric cars are basically small electricity generators that get their energy from a direct electrochemical reaction between oxygen and hydrogen. Hydrogen is stored in a tank from which it is fed into the fuel cell. There it reacts with oxygen and thus produces electricity. The product of this electrochemical reaction is only distilled water. Read more

How many filling stations do we have in Slovakia?

On February 18, 2022, Messer Tatragas company representatives opened the first hydrogen filling station to the public. The gas station is operated in premises leased by Slovnaft. The capacity of the tank is 5 to 6 kg of hydrogen. 1 kg is sold for around 15 euros and a car can be refueled in around 2 to 3 minutes. Since this device is the first in Slovakia, it still pumps at a relatively low pressure of 200 bars. Passenger vehicles can be filled up to 700 bars, where the range is around 600 to 700 km. Read more

How does a hydrogen electric car work in cold weather?

The advantage is the reliability of the entire system in cold weather. Compared to battery accumulators, fuel cells are not subject to degradation during cold weather. Read more

Can't the waste water in the hydrogen electric car system freeze?

Fuel cell systems and water drainage are currently designed so that water cannot freeze in the entire system of the car. Read more

Is battery electromobility a better solution for transport than fuel cells?

It depends on who you ask and what type of transport we are talking about. Hydrogen and batteries are two complementary technologies that complement each other. Why?

1Long-distance freight transport:
Hydrogen currently offers greater potential for transporting goods over longer distances. Despite the hypothetical technological evolution of batteries (batteries with a solid electrolyte), it is unlikely that within ten years it will be possible to recharge the batteries with such an amount of energy that it would be possible to use the increased capacity for a range of over 1000 km without major problems. In addition, current batteries are very heavy, and even with a doubling of the energy density from the current 260 Wh per 1 kg battery to 500 Wh per 1 kg, you would still need a battery with a minimum capacity of 1.5 MW for a long-distance transport over 1000 km, a battery weighing 3 tons. Recharging such a significant amount of electricity is also a problem. How much power would the chargers need to recharge 1.5 MW overnight between shifts? With the hypothetical idea of ​​20 such trucks standing in the parking lot in a row, we reach numbers that make it possible to build not only a more powerful substation, but also a small power plant near such chargers. For that reason alone, it is appropriate to consider changing electricity to another, easily storable energy carrier that can be produced continuously from renewable energy sources. We can also deliver hydrogen to the truck significantly faster and we would not endanger the stability of the transmission system during recharging/refuelling. Thus, hydrogen currently offers greater potential for transporting goods over longer distances.
2Freight transport in cities:
In cities, on the other hand, battery electromobility can play a more significant role due to its high efficiency and low costs. The batteries are great for city traffic, where operators don't need a long range. The advantage of the whole solution is additionally supported by low operating costs and high efficiency thanks to energy recovery and low transport speeds.
3Passenger car transport:
The market for BEVs (battery electric vehicles) is currently a relatively developed market. In addition, significant progress is made every year towards achieving the driving characteristics of internal combustion cars (range, charging speed). BEVs are the ideal solution for standard daily driving and charging at home. Today, BEVs offer a decent range of around 400 km, are highly efficient and locally emission-free. In particular, there will not be an equal competitor for BEVs in suburban transport at present or in the near future. Fuel cell passenger vehicles (FCEVs), on the other hand, cannot compete with BEVs in some areas, although their application is possible, especially considering their specific characteristics. They offer a longer and more stable range, even at higher speeds, especially on highways, their characteristics are similar to internal combustion engines in terms of range. FCEVs can also be a suitable alternative for drivers who live in densely populated areas without adequate recharging options at home. However, the development of FCEVs is currently hindered by high procurement costs and insufficient infrastructure of filling stations, which are also significantly more expensive compared to the construction of charging stations.
4Bus service:
For urban transport with distances in the order of tens of kilometers, the most efficient solution is a battery bus, similar to the case of urban freight transport. Hydrogen buses have greater potential, especially in intercity and long-distance transport, because they offer a more stable and longer range.
5Train transport:
Hydrogen has the potential to replace diesel train transport in parts of the country where electrified railways do not exist. Pilot projects are already operating all over the world, namely in France, which plans to test hydrogen trains from 2023. Similar to Slovakia, where hydrogen trains could run mainly on the Nové Zámky - Prievidza line.

How heavy are hydrogen storage tanks in cars?

Hypothetically storing 4.2 kg of compressed hydrogen at a pressure of 700 bar requires a tank in cars that weighs around 135 kg. Read more

Couldn't hydrogen be liquefied and then refueled like standard gasoline?

This solution is extremely energy inefficient. Liquid hydrogen must be kept at a temperature of -253 °C, and if these conditions are not met, the hydrogen evaporates. Read more

Is hydrogen safe?

All fuels contain a high concentration of energy and can therefore be dangerous under certain conditions. However, hydrogen can be considered as safe or even safer than any other fuel. Read more




Hydrogen economy



cost to produce 1 kg of hydrogen? The price mainly depends on the production method. For the production of green hydrogen, it is also necessary to take into account the different price in individual parts of the world, depending on how much it costs to produce electricity from renewable energy sources. According to the International Energy Agency, the price of hydrogen production is in the following figures:

Steam reforming of natural gas 1 - 3,5 $/kg
Coal gasification 1,2 - 2,2 $/kg
Electrolysis of water 3 - 7,5 $/kg

How much does 1 kg of hydrogen cost at filling stations?

For the end user, the price of hydrogen for 1 kg is currently set at 9.5 euros in Germany (where the most filling stations are located). Converting to kilometers and with an average consumption of 1 kg per 100 km, 1 km in a hydrogen electric car will cost you ~ EUR 0.094. Read more

How will the price come down in the next 10 years?

The hydrogen economy will not be sufficiently developed without the help of state subsidies. To reduce the price, it is necessary to invest in production. In the coming years, support for low-emission and zero-emission (green hydrogen) will prevail in Europe, the aim is to build 40 GW of electrolysers within the EU by 2030 and support the construction of another 40 GW of electrolysers outside the borders to increase imports. Read more