Hydrogen can be transported by pipeline in a mixture with natural gas, but it requires a specific infrastructure and careful handling. When hydrogen is mixed with natural gas, the mixture is called "hydrogen-enriched natural gas" or "HENG." The concentration of hydrogen in the mixture is typically between 10% and 20%.

One advantage of transporting hydrogen in this way is that it allows for the use of existing natural gas pipelines, which can be more cost-effective than building new pipelines specifically for hydrogen. However, there are also several challenges and considerations to keep in mind when using HENG for transportation.

One challenge is that hydrogen is highly reactive and can corrode certain materials, such as some types of steel. This means that the pipelines used for HENG must be made of materials that are compatible with hydrogen, or they must be coated with a protective layer. In addition, hydrogen has a lower energy content than natural gas, so the heating value of HENG is lower. This means that HENG requires a larger volume to provide the same amount of energy as pure natural gas.

Another consideration is that HENG must be carefully handled and stored to prevent leaks or accidents. For example, HENG must be kept at high pressure to reduce its volume and make it easier to transport. This means that the storage and handling facilities used for HENG must be designed to withstand the high pressures involved.

Overall, while hydrogen-enriched natural gas can be an effective way to transport hydrogen, it requires specialized infrastructure and careful handling to ensure the safety and efficiency of the process.

Hydrogen has a lower heating value than natural gas at the same pressure and volume. Its heating value is about 30 % of natural gas. It will not cause any problems at selling gas to customers as the current price for gas distribution is charged in units of energy (distributed KWh) according to heating value and the used invoice systems has to change the heating value of the gas on the basis of actual measurements.  

To provide the same amount of heat it is necessary to deliver more hydrogen than natural gas. An advantage of hydrogen lies in a lower resistance while flowing through pipelines, which means that the mixture of natural gas with hydrogen can therefore flow faster. The present flow rate capacity of pipelines does not pose a limitation for the natural gas and hydrogen mixture as far as the transported heat amount is concerned (Vodíková strategie České republiky, 2021, s. 77-78).