Green hydrogen is often hailed as a critical component of the energy transition, allowing energy transportation and deployment without the emissions associated with fossil fuels. But what is green hydrogen and how can it play a role in the future of energy? Evoqua Water Technologies takes a look at green hydrogen, its benefits, and the challenges faced.
Faced with the climate crisis, industry and governments across the globe are grappling with the energy transition – switching from emission-intensive fossil fuels to more sustainable, low- or zero-emission alternatives. As the world looks to reach net zero emissions by 2050, engineers and scientists are thoroughly assessing all possible solutions to meet energy demands without compromising the integrity and health of the planet. One such solution is hydrogen, more specifically, green hydrogen.
In 2021, global production of hydrogen stood at 94 million metric tons and was valued at around $130 billion[1][2]. By 2050, demand for alternate energy sources could reach as high as 500–680 million metric tons and a market growth rate of 9.2 percent per year.2 Part of the reason for this impressive growth is that hydrogen offers an attractive route towards decarbonization for many industries, from power generation and heavy-duty manufacturing to road transport, shipping, and aviation. According to McKinsey, 2022 has seen around 680 large-scale hydrogen project proposals, equivalent to USD 240 billion in direct investment, a 50% increase since November 2021[3].
What is Hydrogen Used For?
Did you know that 200 years ago, hydrogen-powered the first internal combustion engine? Today, we see it as an energy-dense and light fuel source that creates no pollutants or greenhouse gases. It sounds like exactly what we are looking for but does bring some challenges, which we will explore later. Importantly, it has attracted a large amount of interest and investment, spurring the development of new technologies and refining of existing processes to make the most of it.
Currently, hydrogen is primarily used in the chemical and petrochemical sectors. To tackle the climate crisis, however, humanity is looking to expand its purpose to include transport, buildings, and power generation. Using green hydrogen, we can accelerate the energy transition by enabling the storage of large volumes of ‘clean’ energy.
The use of green hydrogen is expanding across multiple sectors making it more appealing as a resource. The three main areas include industrial feedstock; fuel for transport & power; and as heat for domestic and commercial buildings.
Industrial feedstock includes, for example, green ammonia for fertilizer, or as a contributor to creating products such as glass and steel. The mobility sector is seeing advances in green hydrogen-powered transport. In 2021 London introduced their first hydrogen bus route[4], and shipping companies are actively pursuing vessels powered by ammonia fuel cells to reduce. Utilizing green hydrogen for heating either within domestic or commercial buildings by blending the gas into existing heating systems.
Different Types of Hydrogen & Production
Gray Hydrogen
is made using steam methane reforming using natural gas. In terms of emissions, this is better than black or brown hydrogen (from black and brown coal), but not by much. Currently, it’s the most common form of hydrogen production in many cases.
Blue Hydrogen
is the same as grey hydrogen but minimises carbon emissions by capturing and storing CO2. It is often said to be carbon neutral, though it is impossible to capture all of the carbon emissions, with around 10-20% escaping[3].Green Hydrogen
is made via electrolysis using renewable energy sources, meaning that no emissions are generated in its production or use – exactly what we need for the energy transition. Currently, green hydrogen is just 0.1% of global hydrogen production, it is expected to grow substantially as costs are reduced through efficiency and volume with new technologies[3].Challenges of Green Hydrogen Production
Hydrogen is the most abundant element in the universe, but it must be separated from other elements. Perhaps one of the most significant challenges is that, currently, this separation to create hydrogen is largely achieved using fossil fuels. As of 2022, 99% of the global hydrogen supply comes from fossil fuels, with an established and cost-effective supply chain.1 It means that the production of hydrogen is responsible for generating 830 million tons of CO2 each year[5].
Clearly, switching from fossil fuels to green hydrogen is the answer, but that has cost implications. As of 2022, green hydrogen is around USD 5-6 per kilogram, while blue hydrogen is USD 3-5 and grey hydrogen is the cheapest of all at USD 1.5 per kilogram[6]. It is important to note that this varies substantially across regions but provides some guidance as to pricing. On a positive note, given the amount of investment in green hydrogen and the important role it will play, estimates are that it will reach USD 1.5 per kilogram by 2030. Reaching price parity with blue and grey hydrogen will be critical to green hydrogen’s adoption if no other incentives, like government legislation, encourage its use.
The Future of Green Hydrogen
While its current role is small, green hydrogen is on the rise and will likely play a defining part in the energy transition. Adoption of green hydrogen could prevent up to 60 gigatons of CO2 emissions between 2021 and 2050, or around 6.5% of the cumulative total – a substantial contribution towards environmental targets[1]. To that end, investment and the pursuit of cleaner hydrogen production, new applications, better transportation, and more efficient use could all prove extremely valuable to the energy transition.
Sources
[1] https://www.iea.org/reports/global-hydrogen-review-2022/executive-summary
[2] https://blogs.worldbank.org/ppps/green-hydrogen-key-investment-energy-transition
[3] https://hydrogencouncil.com/wp-content/uploads/2022/09/Hydrogen-Insights-2022-2.pdf
[4] The Second Coming of Hydrogen? London's hydrogen buses - London Reconnections
[5] https://www.iea.org/reports/the-future-of-hydrogen
[6] https://www.pcienergysolutions.com/2022/07/20/colors-of-hydrogen-economics-of-green-blue-and-gray-hydrogen/