Why green hydrogen could play a major role in powering our sustainable future
Hydrogen, the simplest and most abundant element in the universe, has the potential to be the fuel of the future. It's an energy carrier that can store and deliver energy in a usable form. In its pure form, hydrogen is a colorless, odorless and non-toxic gas. It's high in energy, yet an engine that burns pure hydrogen produces almost no pollution, making it a desirable source of power.
How is hydrogen made?
Hydrogen can be produced from a variety of resources. The most common method is through a process called steam methane reforming, which involves reacting natural gas with high-temperature steam. Electrolysis is another method, where an electric current is used to split water into hydrogen and oxygen. How hydrogen is produced determines whether it is defined as grey, low-carbon, green or pink.
Read more about electrolysis here.
Different types of hydrogen
The types of hydrogen refer to the method of production and the associated carbon emissions.
Grey hydrogen is currently the most common type of hydrogen. It's produced from natural gas through steam methane reforming. However, the process emits significant amounts of CO2, making it a less sustainable option.
Grey hydrogen is readily available and relatively cheap to produce, but it's not environmentally friendly due to its CO2 emissions.
Low-carbon hydrogen, also known as blue hydrogen, is similar to grey hydrogen, but the CO2 emissions from the production process are captured and stored or utilized, reducing its carbon footprint. This makes it cleaner than grey hydrogen, as it captures and stores or utilizes the CO2 emissions from the production process. Although this reduces the carbon footprint of blue hydrogen, it still relies on fossil fuels.
Green hydrogen is produced through the electrolysis of water, using renewable energy sources, such as wind or solar power. This process emits no CO2, making green hydrogen the most sustainable option. It's currently more expensive to produce than grey or blue hydrogen due to the high costs associated with renewable energy and electrolysis equipment.
Pink hydrogen is produced by using electricity from nuclear power to split water into hydrogen and oxygen through electrolysis. It's considered low-carbon, but the sustainability of pink hydrogen depends on the method of nuclear power generation and waste disposal.
Pink hydrogen is capable of continuous production, unlike renewable energy sources which are intermittent. However, it comes with the challenges associated with nuclear power, including waste disposal and potential safety concerns.
What can hydrogen be used for?
Hydrogen is a versatile energy carrier with a wide range of potential applications. It can be used in fuel cells to generate electricity and heat, making it a potential energy source for buildings and electric vehicles. It can also be used to store renewable energy, helping to balance the supply and demand on the power grid.
In industry, hydrogen can be used as a feedstock to produce a range of chemicals and fuels. Depending on the type or color of hydrogen, the derivative fuels can be used to lower emissions in energy-intensive industries and long-distance transportation, which is difficult to electrify. Green hydrogen made from renewable energy, for example, can be used to produce green ammonia and eMethanol, which can help decarbonize heavily emitting sectors, such as shipping and aviation. Hydrogen also has the potential to help decarbonize industrial processes that currently rely on fossil fuels, such as steelmaking.
Yet, there are also limitations to using hydrogen. Storing and transporting hydrogen can be challenging due to its low energy density. It also requires a significant amount of energy to produce. Furthermore, while fuel cells are becoming more efficient and cheaper, they are still more expensive than conventional combustion engines.
Why do we need green hydrogen?
Green hydrogen, also referred to as clean hydrogen, is important for several reasons. Firstly, it provides a sustainable way to store and deliver renewable energy. This can help to overcome one of the main challenges of renewable energy sources, which is their intermittency.
Secondly, green hydrogen can help to decarbonize sectors that are difficult to electrify, such as heavy industry and long-distance transport. This makes it a key tool in the global effort to reduce greenhouse gas emissions and combat climate change.
Lastly, green hydrogen can contribute to energy security by providing a way to store and transport energy and diversify energy sources. This is particularly important as the world seeks to transition away from fossil fuels and towards renewable energy sources.
In conclusion, hydrogen holds immense potential as a sustainable energy carrier. While there are challenges to overcome, particularly in terms of cost and infrastructure, the benefits of hydrogen in terms of sustainability and versatility make it a key player in the global energy transition. As we continue to innovate and improve hydrogen production methods and as the cost of renewable and nuclear energy continues to fall, the role of green and pink hydrogen in our energy system is set to grow.
This article was originally published on World Economic Forum's website 7 December 2023. See it here.