[Science World] Essential Condition for an Eco-Friendly Society: 'Hydrogen Energy'

As electric vehicles rise to prominence, hydrogen cars are experiencing sluggish sales. Observing this situation, some say, “Has hydrogen lost its value as a future energy source?” However, from a societal perspective, hydrogen holds immense value that cannot be abandoned. It emits no environmental pollutants and has a high calorific value, making its applications virtually limitless depending on how it is utilized.

There is one important thing to understand about hydrogen: it is a secondary energy source, or an “energy carrier,” that must be produced using other forms of energy. Hydrogen can be obtained by electrolyzing water, but this process requires electricity, meaning other energy inputs are needed to produce hydrogen. It can also be extracted from natural gas, but this too requires natural gas as a raw material and additional energy such as electricity during the conversion process.

Because of this, many believe that “hydrogen ultimately cannot be a clean energy source.” This statement is partly true and partly false, which can be understood by considering coal-fired power plants.

Imagine if every household had a small coal-fired generator to produce electricity independently?what would the urban environment be like? It would likely be difficult to breathe due to fine dust and exhaust fumes. On the other hand, building large coal-fired power plants using the latest technologies allows for effective environmental management. Currently, various buildings and vehicles use large amounts of fossil fuels such as petroleum, liquefied petroleum gas (LPG), liquefied natural gas (LNG), and gasoline. Replacing these energy sources with hydrogen would make our environment significantly cleaner.

Of course, this assumes that carbon dioxide, fine dust, and other pollutants generated at power plants and hydrogen production facilities are effectively managed. In other words, the real reason hydrogen is considered a clean energy source is its ability to comprehensively manage pollutants like carbon dioxide.

Hydrogen also holds great value in the transportation sector, especially for large vehicles such as trucks. This technology is already at the commercialization stage. Recently, a hydrogen truck developed in Korea made headlines after achieving a cumulative driving distance of 10 million kilometers in Switzerland. There is also extensive research into applying hydrogen to automobiles, ships, and other vehicles.

Hydrogen aircraft development is also progressing competitively. Although building hydrogen power plants requires primary energy inputs to produce hydrogen, which may seem theoretically meaningless, utilizing “by-product hydrogen” generated during petroleum refining can reduce the burden on coal and natural gas power plants, adding value.

The key lies in social infrastructure. To commercialize hydrogen energy, various facilities are necessary. Charging stations are essential for operating hydrogen vehicles. Because hydrogen storage requires extremely high-pressure facilities, constructing hydrogen refueling stations involves significantly higher costs compared to LPG vehicle gas stations.

To address these issues, technologies to convert hydrogen into ammonia for distribution are also being considered. Therefore, metering technologies are needed to use hydrogen or ammonia throughout society like LPG or LNG. Continuous research and development of hydrogen fuel cell (HFC) technology, which directly converts hydrogen energy into electricity, must also continue. As these technologies mature, facilities capable of supplying hydrogen to various locations will gradually expand.

Hydrogen is a clean and safe next-generation fuel that can greatly improve the environment depending on how it is handled. The more hydrogen is used in diverse applications, the closer we move toward a carbon-neutral society and a cleaner world.

Jeon Seung-min, Science and Technology Writer