The Role of Hydrogen in Sustainability: Efficiency vs Environmental Impact

You have a point that there are several inefficiencies with hydrogen, especially when you look at the whole process from electrolysis to use in cars, for example. Of course electrolysis itself is not very effective; the efficiency is often around 60-80%, and that still does not include the loss of hydrogen during storage, transport and use.

Standard alkaline electrolyzers can achieve energy efficiency up to about 70%, depending on the voltage and current density used during operation (Lysenko & Ikonnikov, 2023).

High temperature steam electrolyzers, which use natural gas as an anode depolarizer, can increase system efficiency to between 50% and 80% (Pham, 2000).

But on the other hand, hydrogen also has a role, especially in situations where batteries or electricity are not as convenient or sufficient. Such processes where hydrogen is sometimes necessary:

Production of ammonia: It is needed for global fertilizer production, where hydrogen combines with nitrogen to form ammonia.
Steel production: Used as a cleaner alternative to coke as a reducing agent in iron production, which can significantly reduce CO2 emissions.
Chemical industry: It is essential for making chemicals such as methanol, where certain reactions depend on hydrogen.

Hydrogen can also help heavy trucks or shipping, where very high energy density is sometimes required. This ensures that hydrogen vehicles can offer a longer range without the weight and bulk of large battery packs. A problem that will certainly be solved, but this can be an interim temporary solution that is more environmentally friendly than the current fossil fuel solution.

Hydrogen can play a key role in storing excess renewable energy, better to store something than nothing is my motto, as long as it provides a net environmental benefit. On days when more wind or solar energy is produced than necessary, this energy can be used to produce hydrogen, although other methods such as compressed air energy storage (CAES), flywheels, electric power stations -pumped water, thermal energy storage, gravity energy storage, Liquid air energy storage (LAES) can also be used as an alternative (better). This can be used later for power generation or in regions that are difficult to electrify or need energy later when there is no wind or when the sun is not shining. However, each method also has certain limitations and disadvantages.

In addition, the continuous development of fuel cell technology aims to increase efficiency and reduce costs, which may offset the initial disadvantages of energy conversion inefficiency. These developments can increase the economic and operational viability of hydrogen systems, emphasizing the advantages such as faster energy delivery and longer distances without recharging. However, despite these advances, inherent chemical losses in energy conversion remain an ongoing challenge.

In my opinion, the final impact on the environment is a more important metric than actual efficiency when it comes to sustainability. As a result, a less efficient process that uses renewable or sustainable energy sources may ultimately be more environmentally friendly than a more efficient process that relies on fossil fuels. The total ecological footprint of a product or process includes not only the efficiency of energy use, but also the source of energy and other environmental impacts such as emissions and the use of (non-renewable) natural resources.

[Reactie gewijzigd door jdh009 op 29 april 2024 22:41]