Breaking down hydrogen production: green, blue and grey explained
Hydrogen is gaining increased levels of attention as an alternative to traditional power sources, such as battery and internal combustion, offering zero emission solutions for industries such as automotive, aerospace and stationary power. However, some forms of hydrogen are cleaner than others. In fact, hydrogen can be produced in various ways, each with different environmental impacts.
In this article, we’ll break down the three main types of hydrogen: green, blue, and grey, and explain what makes them different.
What is hydrogen production?
To produce hydrogen, it must be separated from the other elements in the molecules where it occurs. This can include extracting it from water or natural gases. The two most common methods for producing hydrogen are steam-methane reforming and electrolysis (splitting water with electricity).
The environmental footprint of hydrogen can be determined by the way it is produced.
Green hydrogen: the cleanest option
Green hydrogen is the cleanest form on the market and is produced through a process of electrolysis powered by renewable energy sources, such as wind, solar, or hydropower. Renewable power sources generate electricity when conditions are optimal – such as on windy or sunny days – and this electrical power can be used to split water molecules into hydrogen and oxygen using an electrolyser.
By using electricity generated from renewable sources, no CO2 is emitted, making this the most environmentally friendly option for hydrogen production. This is also an optimal way of utilising any excess energy generated by renewable sources as surplus power not required by the grid can be stored in the form of hydrogen to manage peaks and troughs in power demand.
In the UK, green hydrogen is a key component of the government’s plans to decarbonise industries and meet climate goals. According to the UK’s Hydrogen Strategy, the country is aiming to produce up to 10 gigawatts (GW) of low carbon hydrogen by 2030, with green hydrogen playing a central role in this target. This shift is expected to contribute significantly to meeting the UK’s net zero emissions target by 2050.
Blue hydrogen: capturing carbon
Blue hydrogen is produced from natural gas using a process called steam methane reforming (SMR), but with an added layer of technology to capture and store the CO2 emissions produced during the process. This method of production allows hydrogen to be created with a lower carbon footprint than grey hydrogen but is not entirely carbon-free.
When used in conjunction with fuel cells, blue hydrogen can offer a cleaner energy solution compared to fossil fuels and a slightly more cost-effective source of power compared to green hydrogen. By integrating carbon capture, blue hydrogen provides a viable pathway to reducing emissions in applications such as transportation and stationary power generation that rely on highly polluting fuels.
Progress is being made in the UK to encourage the generation of blue hydrogen through investments in carbon capture, usage, and storage (CCUS) technologies, which are crucial for its production. The government has also shown commitments to CCUS in the UK CCUS Action Plan, with an aim to unlock the potential for carbon capture across various industries by 2030.
Grey hydrogen: the conventional method
Grey hydrogen is the most common form of hydrogen, produced using SMR without any carbon capture. It’s typically the cheapest form of hydrogen to produce but has the highest environmental impact. The process involves extracting hydrogen from natural gas, however significant amounts of CO2 are emitted as a result.
Despite its cost-effectiveness, grey hydrogen will likely play a diminished role in fuel cell applications, as green and blue hydrogen become the preferred alternatives, enabling industries to push towards zero-emission operations.
In the UK, the transition from grey to green and blue hydrogen is a key part of efforts to decarbonise industries and transport, aligning with the UK’s broader climate goals. In order to do this however, investment in infrastructure and cost reductions must take place to make green hydrogen affordable.
Government regulations and future goals
The UK government is committed to fostering a hydrogen economy as part of its efforts to decarbonise key sectors with plans to support new infrastructure development in the hope to increase adoption and reduce cost. The UK’s Hydrogen Strategy outlines ambitious targets to scale up hydrogen production, with a mixture of green, blue, and potentially grey hydrogen being in mind.
As the UK continues its push towards net zero emissions by 2050, hydrogen will be a critical part of the solution. By supporting green hydrogen development and scaling up blue hydrogen production with carbon capture, the UK can create a cleaner and more sustainable energy system for the future.
If you’d like to find out more about Intelligent Energy’s role in transitioning to green energy, browse our case studies. To get in touch with our experts and to find the right hydrogen fuel cell solution for your applications, fill out our contact form.