Hydrogen can help convert products into no–emission and low–emission forms through emission–intensive applications. Therefore, hydrogen is an essential technology for climate protection. But we are pretending that hydrogen could solve all climate problems and be the ultimate technology. Because first, there are cheaper alternatives in many areas in terms of emission savings, and secondly, hydrogen is only available on a limited basis for economic and technical reasons.
Green electricity produces “Green” Hydrogen.
Second: Green electricity can be “stored” in hydrogen.
Regarding the first: “Green” Hydrogen is obtained by electrolysis. In this process, water (H2O) is decomposed into hydrogen (H) and oxygen (O) components.
Green Hydrogen has excellent potential as a seasonal energy storage system (long–term). It can accumulate energy for a long time and then use it on demand.
Still, it has a problem: It is not freely found in the environment but always combines with other elements (water, H2O or methane, CH4). So, before it can be used in energy applications, it must be released, separated from other elements.
Some processes must be done to realize this separation and obtain free hydrogen, and energy is spent on them. Thus, it is comparable to lithium batteries that store electricity rather than fossil fuels such as natural gas.
Hydrogen has no color of its own. The colors represent the process and starting materials produced by it. Only the “Green” Hydrogen produced with green electricity through electrolysis is virtually emission–free. Of course, emissions can occur while systems are built, but this is true for all hydrogen systems.
The truth is that as a colorless gas when we talk about hydrogen, we often use multicolored terms to refer to it. Many of you like hydrogen green, gray, blue, etc., you have heard. In other words, an easy way to tell how “clean” it is:
- Blue Hydrogen: “Blue” Hydrogen is based on natural gas, just like “grey” Hydrogen. In the production of Blue Hydrogen, this Blue Hydrogen is also called climate–neutral because the CO2 does not (immediately) reach the atmosphere and is “stored” underground. However, there is controversy over this name, as the natural gas used in this process results in more emissions.
- Gray Hydrogen: Obtained from the conversion of natural gas.
- Brown Hydrogen: It is obtained by coal gasification, and carbon dioxide is released. Therefore, it is sometimes called Black Hydrogen.
- Green Hydrogen: This is obtained by electrolysis of water using electricity from renewable energy sources. It is the most expensive, but its price is expected to gradually decrease as the cost of renewable energy and electrolyzers falls.
The real challenge is to be competitive, which requires lots of cheap renewable electricity.
Uses of Green Hydrogen
However, battery and electrical technologies are not possible, depending on the application.
In many, green hydrogen can replace fossil fuels, although not all of them are very mature or simple:
Use brown and gray hydrogen instead. The first step should be replacing all fossil hydrogen currently used in industry, using advanced technologies, and reducing costs. However, the challenge is not negligible. Global hydrogen demand from electricity generation will consume 3,600 TWh, more than the EU’s total annual electricity production.
These are the primary uses of green hydrogen:
- Transportation: Transport is undoubtedly one of the most promising hydrogen applications. Batteries are winning the competition in today’s light transport.
- Energy Store: This is undoubtedly one of the most promising hydrogen applications of a seasonal energy storage system. We will see that the cost of electricity is cheap and will be redundant as there is no place to consume it. They are used for applications, on–demand electricity generation, or other applications.
- Heating: Domestic and industrial heating is not always an electrified sector. In addition, existing infrastructure (such as natural gas grids) can increase demand.
For example, mixing up to 20% by volume of hydrogen in an existing natural gas network requires minimal changes to the end–user network or appliances.
Advantages and Disadvantages of Green Hydrogen
So let’s take a look at some of its most important positive features:
- 100% Sustainable: Green Hydrogen does not emit polluting gases during combustion or production.
- Storable: Hydrogen is easy to store. This allows it to be used later for other purposes and after manufacture. They are also easier to use than lithium–ion batteries because they are lighter.
- Portable: It can be transported up to 20% like natural gas, which can be transported with the existing natural gas infrastructure. Increasing this percentage will require replacing different elements in existing gas infrastructures to bring them into line.
However, Green Hydrogen also has downsides to keep in mind:
- High Energy Consumption: In general, hydrogen production in general and Green Hydrogen require more energy than other fuels.
- Safety Considerations: Hydrogen is a volatile and flammable element, and therefore extensive safety measures are necessary to prevent leakage and explosions.
How much does green hydrogen cost?
It’s still expensive today. For Green Hydrogen prices to fall, renewable energy prices and electrolysis prices must fall. Reducing the cost of electrolysis is critical to lowering the price of Green Hydrogen, but this will take time.
What should be considered about hydrogen imports?
Geographically and physically, there are perfect conditions for Green Hydrogen production in countries with a large area, plenty of sun, and wind. These are countries located in the relative Global South. However, there is a risk of adverse effects on humans and nature when large–scale (Green) Hydrogen export production is carried out in exporting countries.
There are currently no binding regulations for hydrogen imports. Therefore, Germany and Europe have the opportunity to take the lead in this regard and develop strict and controllable standards with the strength of their markets. When such regulations are coupled with robust sanctions, hydrogen can create a sustainable, global enterprise, a socially just, ecologically harmless, and economically successful enterprise.