Is Green Hydrogen Renewable?

Introduction

Green hydrogen is hydrogen fuel that is produced through renewable energy sources such as wind or solar power. It is called “green” because the production process utilizes renewable energy and emits little to no greenhouse gases. The rising interest in green hydrogen stems from its potential to help decarbonize multiple sectors and support the global transition to renewable energy.

Hydrogen is considered a clean fuel because its use produces only water as a byproduct, with no carbon emissions. However, most current hydrogen production comes from fossil fuels through a process called steam methane reforming which has a large carbon footprint. Green hydrogen offers a more sustainable way to produce hydrogen fuel by using electrolysis powered by renewable electricity to split water molecules into hydrogen and oxygen.

With countries around the world setting goals to reach net zero emissions, green hydrogen is seen as a critical part of the solution. It can provide clean power across industries like transportation, manufacturing, and heating while also serving as a form of energy storage. The development of green hydrogen at scale could help accelerate the renewable energy transition.

How Green Hydrogen is Produced

Green hydrogen is produced through electrolysis, which uses electricity to split water into hydrogen and oxygen. This process is powered entirely by renewable energy sources like solar, wind, hydropower or geothermal instead of fossil fuels. According to MECO, the most common form of electrolysis for green hydrogen production is alkaline electrolysis, which involves an electrolyte solution of water and potassium hydroxide. An electrical current is applied across the electrodes in the water, causing the bonds between the hydrogen and oxygen to break down and separate into two gases.

Other emerging methods like proton-exchange membrane (PEM) electrolysis are also being used. The key is that the electricity used in the electrolysis process must come from 100% renewable sources like solar or wind for the resulting hydrogen to be considered green hydrogen. This zero-emission production via electrolysis is what distinguishes green hydrogen from traditional gray hydrogen made using fossil fuel-based methods.

Benefits of Green Hydrogen

Green hydrogen provides a clean, renewable, and versatile energy carrier with many potential benefits. As an energy source, green hydrogen emits zero greenhouse gases or air pollutants when used, making it a carbon-free fuel option (https://www.activesustainability.com/sustainable-development/what-is-green-hydrogen-used-for/). This gives green hydrogen significant environmental advantages over fossil fuels like coal and natural gas that produce carbon dioxide and other emissions when burned.

Because green hydrogen is produced through the electrolysis of water powered by renewable energy sources like solar or wind, it can be considered a renewable fuel as well. The hydrogen production process uses sustainable electricity and water as inputs rather than finite resources. This makes green hydrogen a versatile energy carrier that can integrate more renewable power into the energy system (https://www.nature.com/articles/s41598-021-92511-6).

Overall, green hydrogen provides a way to store and transport clean energy at scale. It offers a sustainable pathway to decarbonize hard-to-abate sectors like industry, transportation, heating and more. With its clean and renewable properties, green hydrogen can facilitate the transition to a net zero emissions economy.

Challenges of Green Hydrogen Adoption

While green hydrogen has enormous potential as a clean energy source, there are several key challenges to scaling up its adoption and use currently. Some of the main challenges include:

High costs: Producing green hydrogen is still an expensive process compared to using fossil fuels. The production costs of green hydrogen are estimated to be 2-3 times higher currently than conventional hydrogen production from natural gas. The high costs are mainly due to the expense of renewable electricity and electrolyzers needed to produce green hydrogen via electrolysis [1].

Scaling up production and infrastructure: Significant investment and infrastructure development is needed to scale up production capacity for green hydrogen. This includes building more large-scale renewable energy projects to power electrolysis and developing transmission lines, pipelines, storage facilities, filling stations and transportation for hydrogen [2]. The scale of infrastructure needed globally is estimated in the trillions of dollars.

Overall, while green hydrogen holds major potential as a renewable energy source, currently high production costs and the lack of infrastructure present challenges to wider adoption. Bringing down costs through technology improvements and building out a whole new hydrogen production and distribution infrastructure will be key to unlocking the promise of green hydrogen.

Green Hydrogen Projects

There are several notable green hydrogen projects in development and under construction around the world. These pilot projects aim to demonstrate the real-world feasibility and scalability of hydrogen production using renewable energy sources.

Some of the largest announced green hydrogen projects include:

• The NEOM Green Hydrogen Project in Saudi Arabia, which plans to use 4 gigawatts of wind and solar energy to produce 650 tons of green hydrogen per day, starting from 2026 (https://www.hydrogeninsight.com/production/impossible-dreams-the-11-biggest-green-hydrogen-projects-announced-around-the-world-so-far/2-1-1517618).
• Sinopec’s Ordos Green Hydrogen Project in China intends to use 5 gigawatts of solar and wind power to produce 350,000 tons of green hydrogen annually (https://www.linkedin.com/pulse/largest-green-hydrogen-projects-world-futurefuels).
• The HyDeal España project in Spain, backed by companies like Enagás, CAC, and Fertiberia, plans to install 3.6 gigawatts of solar power capacity to produce 300,000 tons of green hydrogen yearly, starting in 2025.

In the United States, there are also several high-profile green hydrogen projects underway, such as:

• The St. Gabriel Green Hydrogen Plant in Louisiana by Air Products, which will use wind and solar energy to make over 250 tons of green hydrogen daily (https://www.airswift.com/blog/green-hydrogen-projects-usa).
• The Kingsland Green Hydrogen Hub in Texas by New Fortress Energy, targeting over 50 tons of green hydrogen production per day.
• The Advanced Clean Energy Storage Project in Utah by Mitsubishi Power Americas and Magnum Development, which will couple 600 megawatts of solar generation with green hydrogen storage.

These projects aim to demonstrate and scale up green hydrogen in order to accelerate the transition to renewable energy across multiple sectors.

Green Hydrogen Policies

Governments around the world are implementing policies and incentives to boost the production and adoption of green hydrogen. The main policy goals are to make green hydrogen cost-competitive with fossil fuel-based hydrogen, support technology innovation, and create demand in hard-to-decarbonize industries.

The European Union unveiled its Hydrogen Strategy in 2020, aiming to install at least 40 gigawatts of renewable hydrogen electrolyzers and produce 10 million metric tons of green hydrogen by 2030. The strategy includes funding programs for research and development as well as building hydrogen infrastructure like refueling stations and pipelines.

In the United States, the Bipartisan Infrastructure Law provides $9.5 billion for clean hydrogen hubs to demonstrate hydrogen production, processing, transport, storage and end-use. Several U.S. states have additional incentives for green hydrogen production and use in transportation.

China aims to have over 50,000 hydrogen vehicles on the road by 2025 and is investing heavily in hydrogen refueling stations. The country also provides subsidies for purchasing fuel cell vehicles. Other Asian countries like Japan, South Korea and Singapore have announced major green hydrogen plans and targets.

Overall, government support and strategic policymaking are crucial to scale up green hydrogen and bring down costs through economies of scale and technological improvements. Policy incentives like investment tax credits, production credits, capital grants, and guaranteed loans can accelerate growth in the nascent green hydrogen industry.

Green Hydrogen Storage and Transportation

One of the key challenges for enabling widescale adoption of green hydrogen is finding effective ways to store and transport it. Unlike fossil fuels, hydrogen is a gas at ambient temperatures and pressures, which makes it more difficult to contain and ship efficiently. There are several methods being explored for large-scale hydrogen storage and transportation:

Compressed hydrogen gas is the most common way to store hydrogen today. The gas is compressed and held in high-pressure tanks for storage and transport by truck or rail. However, compression only reduces the volume by up to 800 times, so the energy density by volume is still low. This method works for small volumes but not for massive, long-distance transport and storage. New high-pressure tank designs and materials are being developed to improve compressed gas storage and transport.

Liquefied hydrogen converts the gas into a liquid by cooling it to extremely low cryogenic temperatures around -253°C. This reduces the volume by 800 times further, but requires significant amounts of energy for liquefaction. Special cryogenic tanks are needed to maintain the liquid state. Liquefied hydrogen enables high density storage and ocean transport, but keeping it cold during storage and transport is challenging.

New materials are being developed that can physically absorb hydrogen at lower pressures and ambient temperatures. Metal hydrides, metal-organic frameworks, and porous polymers are examples. This provides a compact and safe way to store hydrogen, but absorption/desorption kinetics and cyclability need improvement. Weight and volumetric density also need to increase significantly for viability.

Chemical storage via power-to-gas converts hydrogen to other compounds like ammonia or liquid organic hydrogen carriers. This enables high density storage and utilizes existing transport infrastructure for fossil fuels. However, the conversion processes have energy losses and add process complexity. Improving reaction kinetics and reducing costs are active areas of research.

The Future of Green Hydrogen

There is great optimism surrounding the future potential of green hydrogen. As the world transitions to cleaner forms of energy, green hydrogen is projected to play a major role given its versatility as an emissions-free fuel source across many sectors including transportation, power generation, and industry. The key to unlocking the full potential of green hydrogen is continuing to drive down costs and scale up production and deployment.

Many industry analysts and organizations predict significant cost reductions for green hydrogen production in the coming years and decades. According to IRENA, green hydrogen costs could fall 30-50% by 2030 based on continued declines in renewable energy costs coupled with increased scale and utilization of electrolyzers (NextEra Energy). BloomberNEF predicts a further halving of green hydrogen costs by 2050 as the industry scales up. With increased scale and more efficient processes, some project the possibility of green hydrogen achieving cost parity with conventional hydrogen by around 2030 (Forbes).

Major investments are being made globally both on the public and private side to scale up green hydrogen projects and infrastructure. The U.S. recently passed the Inflation Reduction Act which provides tax credits for clean hydrogen production. The E.U. aims to install 40 GW of renewable hydrogen electrolyzers by 2030. Companies like NextEra Energy are investing billions into green hydrogen with a view towards commercial scale viability in the next decade. If costs continue falling in line with projections, green hydrogen has an extremely promising future as a versatile, sustainable energy solution.

Is Green Hydrogen Truly Renewable?

Green hydrogen is produced through the electrolysis of water using renewable energy like solar or wind power. This process separates the hydrogen from the oxygen in water to create clean hydrogen gas. Since the production relies entirely on renewable energy sources like solar and wind, many consider green hydrogen to be a renewable form of energy itself.

However, some argue that while the production process of green hydrogen utilizes renewable resources, the hydrogen gas itself should not be classified as renewable. The reasoning is that hydrogen is an energy carrier or storage medium, not a primary energy source like solar, wind or hydropower. Renewable resources are used to produce the hydrogen, but the hydrogen itself is not renewable in a closed loop like other renewable sources.

Ultimately, whether green hydrogen is considered renewable depends on the definition used. By some definitions, it qualifies as the production process exclusively uses renewable energy sources. But by other, narrower definitions, green hydrogen is not renewable itself but rather relies on renewable power for production. This debate remains split among experts.

Conclusion

In summary, green hydrogen is produced through the electrolysis of water using renewable electricity from solar or wind power. This process does not generate any carbon emissions, allowing green hydrogen to be considered a clean, renewable fuel source. The benefits of green hydrogen include its versatility as an energy carrier and storage medium for renewables, its potential to decarbonize hard-to-abate sectors like heavy industry and long-haul transportation, and its ability to strengthen energy security. However, challenges remain in scaling up green hydrogen production to bring down costs, building out infrastructure for storage and transportation, and establishing policies and incentives to support widespread adoption. While many promising green hydrogen projects are emerging around the world, it remains a nascent industry requiring technological and economic advancements to fully realize its potential. But the fundamentals of green hydrogen production using renewables align with the very definition of renewable energy. So while work remains to scale its viability as an energy solution, green hydrogen produced sustainably through electrolysis can indeed be considered a renewable source of energy.