FAQs

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.