Hydrogen FAQs

Our panel of experts have worked on providing the most accurate answers to the most frequent asked questions around the hydrogen technology. Ignite your curiosity and discover the world of sustainability.

Hydrogen is the first element in the periodic table and was discovered in 1766 by Henry Cavendish. It is used to synthesise ammonia for agricultural fertilizer, methanol for pharmaceutical applications, hydrogenations of oils and fats, and lately as a clean fuel.

Reference: Royal Society of Chemistry

The classification of colours for hydrogen corresponds to the process used to extract hydrogen and the GHG emission profile of the energy source. Grey hydrogen is the conventional method of producing hydrogen from fossil fuels, primarily through steam methane reforming or coal gasification. Nonetheless, this process releases CO2 emissions into the atmosphere without any carbon capture or utilization. Blue hydrogen is produced similarly to grey hydrogen. However, the key differentiating factor for blue hydrogen is that the CO2 emissions generated during production are captured and either stored or utilized through carbon capture and storage (CCS) or carbon capture and utilization (CCU) technologies. Green hydrogen is generated through electrolysis powered by renewable sources such as wind or solar.

Reference: International Renewable Energy Agency

H2 combustion produces only water vapour, making it a clean and environmentally friendly fuel. Hydrogen can be produced from renewable sources and stored for later use, enabling grid-scale energy storage and facilitating the integration of intermittent renewable energy. Hydrogen can be used in various applications, including transportation, power generation, and industrial processes. Hydrogen has a high energy density, making it a potential solution for long-range transportation and energy-intensive industries.

Reference: U.S. Department of Energy

Hydrogen is a flammable gas, and safety measures must be taken during production, storage, and use. However, hydrogen can be used safely by following proper handling procedures, employing appropriate infrastructure, and implementing stringent safety standards and regulations. Various safety technologies and practices, such as leak detection systems and hydrogen sensors, have been developed to ensure safe use of hydrogen.

Reference: Hydrogen Tools

The overall efficiency of hydrogen as a fuel source depends on the entire production, storage, and utilization chain. The efficiency of hydrogen production methods, such as electrolysis or steam methane reforming, varies. Fuel cell systems that convert hydrogen into electricity can achieve high efficiencies, typically ranging from 40% to 60%, depending on the specific type and application.

Reference: U.S. Department of Energy

Some of the challenges of using hydrogen as a fuel source are related to cost, storage, scalability and production. Firstly, production, storage, and infrastructure development can be expensive. Secondly, hydrogen has low volumetric energy density, requiring specialized storage and transportation methods. Thirdly, the widespread adoption of hydrogen as a fuel source requires significant infrastructure development and market penetration. Lastly, scaling up the production of hydrogen from renewable sources is essential to maximize its environmental benefits.

Reference: U.S. Department of Energy

A fuel cell is an electrochemical device that converts the chemical energy of hydrogen and oxygen (or other fuels and oxidants) into electricity and heat. It consists of an electrolyte sandwiched between two electrodes: an anode and a cathode. Hydrogen fuel is supplied to the anode, where it is split into protons (H+) and electrons (e-). The protons pass through the electrolyte, while the electrons travel through an external circuit, creating an electrical current. At the cathode, the protons, electrons, and oxygen combine, producing water as the only byproduct and heat.

Reference: U.S. Department of Energy

The environmental impacts of hydrogen production depend on the method used. Green hydrogen, produced through renewable-powered electrolysis, has minimal environmental impacts and is considered a sustainable option. Grey hydrogen, produced from fossil fuels without carbon capture, contributes to greenhouse gas emissions. Blue hydrogen involves capturing and storing or utilizing carbon emissions during production, reducing its environmental footprint. Other potential environmental impacts include water usage, land requirements for infrastructure, and the potential for unintended environmental consequences associated with large-scale hydrogen production.

Reference: International Energy Agency

The cost of producing hydrogen varies depending on the production method and the scale of operation. Currently, hydrogen production from fossil fuels (grey hydrogen) is generally cheaper due to mature technologies and infrastructure (~ 1.50 USD/Kg). However, the cost of producing hydrogen from renewable sources (green hydrogen  ~5 USD/Kg) is expected to decrease as renewable energy costs decline and electrolysis technologies advance.

Reference: International Energy Agency

Hydrogen plays a crucial role in achieving net-zero emissions by serving as a clean and versatile energy carrier. Hydrogen can be used as a low or zero-emission fuel in sectors that are challenging to electrify directly, such as heavy-duty transportation, aviation, shipping, and certain industrial processes. Also, it can be used to store and convert renewable energy into a storable form, addressing the intermittency of renewable sources like solar and wind. In the case of green hydrogen, it has the potential to become a carbon-free fuel. By scaling up the production of green hydrogen, emissions associated with hydrogen production can be eliminated, contributing to overall decarbonization efforts.

Reference: International Energy Agency

Would you like to explore deeper the world of hydrogen? The Australian Hydrogen Council, CSIRO and the Department of Climate Change, Energy, Environment and Water have developed an interactive space where you can find answers to more particular questions. Click on the following button to discover more.


HSA´s purpose is to promote the significance of hydrogen as a clean fuel and energy storage solution through the organization of events to foster engagement among scientists, academics, the business community, the government and the general public. The association also works in the development of policies to positively influence political processes for the energy transition and collaborates in the dissemination of hydrogen industry information.

Becoming a member of the Hydrogen Society of Australia is an easy process. First, click on “members portal”. Then, go to “Become a member” and choose the membership category that fits your profile. Fill out the format with your information and sign up to enjoy all the benefits that HSA has for you.

Once you are a member, you are able to attend HSA´s networking events, participate in webinars, receive special offers to attend to conferences and the annual celebration of the National Hydrogen Day every October 8.

If you are a student, you are able to apply for a concession fee which will allow you to have access to webinars & in-person events, meet experts in the hydrogen industry and keep you updated with the last advances in the area. As a student, it is important to start building a solid network around the areas that you are interested in. If you are interested in hydrogen as a potential renewable fuel, don´t miss the opportunity to be part of this prestigious community.

HSA can definitely help you to grow your knowledge and boost your career around the hydrogen industry. A monthly newsletter is published on the website and sent to your email as well. This document contains information about events, webinars, courses, career opportunities, member benefits, and past events reviews. Everything is prepared with detail, so you can take advantage of all the available material.

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