Are Hydrogen Engines Key to Carbon Neutrality?

By Santiago Vivas, Erena Estellés Published on Mar. 26, 2024

The overall transportation industry is under pressure to decarbonize and reach ambitious net-zero targets. Consumers increasing greener alternative demands, added to the changing government regulations and technological advances, enable the transition into a cleaner economy.

In 2019, the European Commission announced its Green Deal. It was an ambitious package of measures ranging from cutting greenhouse emissions to heavily investing in research and innovation with the objective of carbon neutrality. It planned to achieve a 55% net reduction in greenhouse gas emissions by 2030 and net carbon neutrality in the EU by 2050. As green energy, hydrogen presents many advantages in industries looking to reduce emissions.


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Firstly, it’s essential to understand the three main types of hydrogen energy used today:

Gray Hydrogen is a common form of hydrogen energy. Gray hydrogen is created using steam methane reformation but without capturing the greenhouse gases made in the process. It's the least expensive or sustainable form of hydrogen production.

Blue hydrogen combines natural gas and heated water in the form of steam. Blue hydrogen is often labeled as “clean.” However, research from Cornell and Stanford shows that the carbon footprint to create blue hydrogen is more than 20% greater than using natural gas or coal directly for heat. It’s also about 60% greater than using diesel oil for heat.

Download our recent report: 2023 Hydrogen Report

Green hydrogen is produced without harmful greenhouse gas emissions. It's made by using clean electricity from surplus renewable energy sources, such as solar or wind power, to produce a clean hydrogen. Due to its expensive production cost, green hydrogen only makes up a minimal percentage of the overall hydrogen produced worldwide.

Hydrogen engines in the automotive industry and trucking

A decade ago, hydrogen power and electricity were two major contenders for replacing internal combustion engines. On paper, hydrogen seems to be the ideal alternative as it offers a similar refueling time and range while producing zero emissions. However, the effect on gas prices caused by Russia’s invasion of Ukraine, combined with declining battery costs and the launch of new battery-powered vehicles, have enabled electric vehicles, or EVs, to reach total cost of ownership (TOC) parity for the first-use cases.

Hydrogen cars have been around since the 1960s, when General Motors launched the Electrovan. However, they haven’t been able to compete with EVs despite EVs’ longer charging times. At the end of 2021, there were only approximately 25,000 hydrogen cars, about 650 hydrogen fueling stations worldwide, and only two models available to the public: the Toyota Mirai and the Hyundai Nexo. In contrast, EV sales doubled in 2021, reaching 6.6m around the globe for 16.5m electric vehicles on the road from some of the world’s largest manufacturers.

For electric vehicles, the efficiency ranges from 70% to 80%, depending on the model. While for hydrogen cars, the efficiency is approximately 25% to 35%. This means that a hydrogen car consumes two to three times more energy than an EV. However, hydrogen represents an opportunity in scenarios where batteries are insufficient, such as for more extensive scale or long-distance transportation in the trucking sector.

Hydrogen-fueled trucks

Batteries can be inefficient as they require long charging times. They are heavy and lack the infrastructure to support the trucks in long distances, unpredictable routes, and strict driving time regulations. Thanks to its faster refueling times, greater range, and lower weight which increases payload capacity, hydrogen energy becomes an exciting alternative to batteries and traditional fuels. Companies, such as Volvo Trucks, have already started testing hydrogen-fueled trucks with a 1000 km range. However, there are still some main challenges to mass adoption.

Due to the investment cost and the complex value chain supply required, hydrogen fuel stations are scarce today. Hydrogen stations don't require grid upgrades, have a smaller carbon footprint, and have faster refueling times, meaning more trucks can use the facilities than e-charging stations. As vehicle demand increases and the cost decreases, hydrogen fuel stations, or HRS, will become more attractive. Research by McKinsey shows that operators of HRS could break even as early as 2025 when serving a small fleet of trucks. And in the long run, research suggests that hydrogen trucking will be cheaper than diesel overall. However, there remains uncertainty regarding the timing, business model, and whether to support passenger cars and long-haul transportation.

A healthy ecosystem needs to develop a secure supply and demand for hydrogen-fueled trucks to be the norm in the future. According to McKinsey, the initial CAPEX required to build and maintain the infrastructure, the return on investment is likely to be lower and will take more time to bear its fruits. For an ecosystem to work and be efficient, McKinsey illustrates some examples of parameters that need to be present:

  • Governments to create a stable legal framework
  • Players willing to provide the financing for expansion
  • Hydrogen producers can produce green hydrogen at a lower cost and in sufficient quantity
  • HRS providers to build enough refueling stations

Ongoing projects

Hyzon Motors is a company focused on rapidly accelerating the adoption of zero-emission for medium to heavy applications in the transportation sector powered by hydrogen. The company recently announced its “Repower” plan to turn used diesel vehicles into hydrogen fuel cell trucks. The company, headquartered in the U.S., is a perfect example of the many applications hydrogen power can have in the mobility sector. Its valuation of over $450m shows investors are betting on hydrogen’s potential. Learn more about the company's mission in this video:

Hydrogen energy in the aviation industry

It's essential to highlight that continuous growth in air travel demand has increased aviation emissions over the past years, accounting for 2.5% of global CO2 emissions and 1.9% of greenhouse gas emissions in 2020.

Approximately two-thirds of these emissions came from short- and medium-range aircraft, which account for 90% of all flights. Even if efficiency improvements continue to accelerate, aviation emissions will double to two gigatons of CO2 by 2050. It suggests that further short- and long-term decarbonization measures, such as using Sustainable Aviation Fuels (SAFs), radical aircraft designs, andelectric- and hydrogen-powered aircraft, will be required to achieve carbon neutrality by 2050.

For this reason, institutions such as the International Air Transport Association, or IATA, have already taken action. They have approved resolutions, which include a range of short- and long-term decarbonization solutions. The solutions ranged across sectors such as Sustainable Aviation Fuels (SAFs), new aircraft technology, and new zero-emissions propulsion systems based on electric batteries and hydrogen power.

Sustainable Aviation Fuels (SAFs)

Sustainable Aviation Fuels, or SAFs are produced from sustainable feedstocks, including biological and non-biological sources like solid waste from homes and non-palm waste oils from animals or plants. SAFs look like a promising option to decarbonize aviation since they reduce up to 80% in carbon emissions over the fuel lifecycle compared to conventional jet fuel.

However, SAFs are currently more costly than traditional fossil jet fuels due to the availability of sustainable feedstocks and the continuing development of new production technologies. While the industry works to develop this technology further, commercial airlines are opting for blending SAFs with traditional jet fuel. For instance, in February 2021, the Dutch airline, KLM, operated the first passenger flight partly flown with synthetic kerosene from Amsterdam to Madrid.

Hydrogen fuel

Hydrogen fuel is emerging as high-potential technology which offers significant energy efficiency and carbon neutrality benefits to the aviation industry. It’s one of the most promising zero-emission technologies for future aircraft. Nevertheless, hydrogen has a higher volumetric density than kerosene, meaning that the space it occupies is around four times larger than that of kerosene. Thus, it requires larger tanks on the aircraft and adjusted aircraft designs, such as blended wing body aircraft.

Ongoing projects

Despite its limitations, many ongoing projects aim to prove the potential of hydrogen propulsion to shape the development of zero-emission aircraft. An example is the Airbus ZEROe concept aircraft, which aims to explore a variety of aircraft configurations and hydrogen technologies to develop the first zero-emission commercial aircraft by 2035.

Another example is ZeroAvia, a startup building the world's first practical zero-emission aviation powertrain based on electric propulsion powered by the hydrogen fuel cell system. The company is preparing to test a Dornier 228 aircraft within the next few weeks before bringing its product to the market by the end of 2024.

Val Miftakhov, ZeroAvia’s CEO, believes that hydrogen will be the primary way to achieve zero climate impact from aviation and potentially other sectors like heavy-duty ground and marine shipping. Check out this video to learn more about ZeroAvia’s project:

The future of carbon neutrality

Although there are reasons to be optimistic about hydrogen in the future, many challenges remain to be solved. For instance, we need to overcome barriers to bringing costs down, improving the infrastructure, and transitioning from gray and blue hydrogen to green hydrogen.

Companies such as Lhyfe, Green Independence, and Proof Energy hope to democratize access to renewables by producing green hydrogen to pave the way for a carbon-neutral economy.

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However, the cost must drop drastically for hydrogen to become a standard fuel. Currently, blue hydrogen is 30% to 80% more expensive, while green hydrogen is four times more expensive than traditional fuel sources. While these prices are expected to decrease as the cost of renewable electricity and electrolysis fall, governments around the globe must promote investments in green hydrogen technology, infrastructure, and transportation. Hydrogen will not be the only fuel of the future, but we believe it will play an essential role in shaping the future of energy and mobility.