As the world races toward decarbonization, some sectors remain difficult to electrify. Heavy industries such as steel, cement, and chemical production account for nearly a quarter of global CO2 emissions. These industries rely on energy-dense fuels and high-temperature processes, making it hard for renewable electricity to replace fossil fuels. Green hydrogen offers a promising alternative, particularly when it is produced using hydropower, providing a clean fuel for industries resistant to other green solutions.
Hydropower-generated hydrogen has emerged as a potential solution for decarbonizing energy-intensive industries. This article explores the role hydropower plays in hydrogen production, the benefits and challenges of hydrogen in heavy industry, and how green hydrogen can be scaled to meet global demands.
The Role of Hydropower in Producing Green Hydrogen
Hydropower is the world’s largest source of renewable electricity, providing consistent energy output. It stands out from other renewables like solar and wind, which fluctuate based on weather conditions. Hydropower’s consistency makes it a prime candidate for generating green hydrogen, where surplus electricity can be used to power electrolysis—the process of splitting water into hydrogen and oxygen.
Hydropower’s Energy Consistency Advantage
Hydropower delivers a steady supply of electricity, making it ideal for electrolysis. In contrast, solar and wind energy depend on weather conditions, leading to power fluctuations. Hydropower plants, especially dam-based systems, offer the flexibility to regulate energy production based on demand. This ability allows hydropower to act as a multi-functional energy hub, producing both electricity and hydrogen. It also stabilizes energy supply by generating hydrogen during low-demand periods, which can later be used in industry or power generation.
However, not all hydropower systems are equally effective. Run-of-river hydropower plants, which depend on river flow, experience seasonal variations. In contrast, reservoir-based hydropower stations store water, offering more control over electricity production, ensuring that hydrogen generation remains stable.
The Electrolysis Process: Converting Water into Hydrogen
Electrolysis is key to producing green hydrogen, powered by hydropower. It works by passing an electrical current through water, splitting H2O molecules into hydrogen and oxygen. There are three main types of electrolysis used for hydrogen production:
Alkaline Electrolysis
This mature technology uses a liquid alkaline solution to conduct ions. While alkaline electrolysis is durable and cost-effective, it is slower and less efficient compared to newer methods.
Proton Exchange Membrane (PEM) Electrolysis
PEM electrolyzers use a solid membrane to conduct ions, offering faster responses and greater operational flexibility. This makes them a good match for renewable energy sources, including hydropower.
Solid Oxide Electrolysis
Still in the early stages, this high-temperature method promises high efficiency but is too costly for widespread use today.
By utilizing hydropower, electrolysis becomes more efficient. The process ensures a steady energy supply and higher hydrogen output, allowing for more sustainable and large-scale hydrogen production. Still, challenges related to infrastructure, environmental impacts, and economic feasibility must be addressed to enable large-scale hydrogen production.
Decarbonizing Heavy Industry with Hydrogen from Hydropower
Hydrogen offers an alternative to the fossil fuels used in heavy industries like steelmaking, cement production, and chemical manufacturing. These sectors consume enormous amounts of energy, mostly in the form of fossil fuels, leading to high CO2 emissions. By using green hydrogen, these industries can dramatically reduce their carbon footprints.
Hydrogen in Steelmaking: Direct Reduction of Iron (DRI)
In steelmaking, hydrogen can replace coal in the Direct Reduction of Iron (DRI) process. Traditionally, steel production involves using carbon from coal to remove oxygen from iron ore, releasing CO2 in the process. Hydrogen, when used instead of coal, removes the oxygen, producing iron and water vapor as byproducts. This cleaner process can lead to near-zero emissions in steel production.
Challenges in Adopting Hydrogen for Steelmaking
Several factors complicate the widespread adoption of hydrogen-based steelmaking:
- Infrastructure: The global steel industry has relied on blast furnaces for decades. Switching to hydrogen requires substantial investment in new infrastructure, making retrofitting existing plants costly.
- Hydrogen Supply: Producing enough green hydrogen to meet steel industry demands is no small task, particularly in regions lacking hydropower resources.
- Cost Competitiveness: Hydrogen-based steel production is still more expensive than traditional methods, primarily due to the high cost of hydrogen production. However, as hydrogen technologies advance, costs are expected to decrease.
Hydrogen in Cement Production: Hydrogen-fueled Kilns
Cement production, responsible for around 7-8% of global emissions, relies heavily on fossil fuels for high-temperature kilns. Hydrogen can replace these fuels in cement kilns, offering a cleaner alternative.
Issues with Hydrogen Use in Cement Kilns
- Efficiency: Hydrogen combustion releases water vapor, which may reduce kiln efficiency.
- Cost: The expense of producing green hydrogen is a barrier for cement plants, and the infrastructure needed to transport hydrogen to these plants is limited.
Despite these challenges, pilot projects in several countries are already exploring hydrogen-fueled cement production. If successful, hydrogen could significantly cut emissions from one of the world’s most polluting industries.
Scaling Green Hydrogen Production with Hydropower
Scaling green hydrogen production will require major advancements in technology, infrastructure, and policy. Hydropower provides a robust platform for expanding hydrogen generation, but its development is regionally limited, and several environmental and logistical challenges must be overcome.
Hydropower Capacity and Regional Disparities
Countries with abundant water resources, such as Canada, Norway, and Brazil, are well-positioned to lead in green hydrogen production. Norway, for example, generates 95% of its electricity from hydropower, making it a global leader in producing and exporting green hydrogen.
However, regions without access to hydropower face limitations. Hydropower generation is geographically dependent, and many parts of the world lack the necessary water resources to scale hydropower effectively. In these regions, other renewable energy sources like wind and solar may be integrated with hydropower in a hybrid system to stabilize energy production and increase hydrogen output.
Environmental and Social Impacts of Expanding Hydropower for Hydrogen
While hydropower is cleaner than fossil fuels, expanding it comes with environmental and social costs. Building new dams can disrupt ecosystems, displace local communities, and affect agriculture and fisheries downstream. Additionally, dam reservoirs can release methane, a potent greenhouse gas, as submerged organic matter decomposes.
Balancing the need for clean energy with the environmental impact of hydropower projects is crucial. Expanding hydropower should focus on upgrading existing facilities or developing small-scale hydropower projects, which carry fewer environmental risks.
Hybrid Energy Systems: Combining Hydropower with Wind and Solar
Hybrid systems that integrate hydropower with solar and wind energy can overcome regional limitations. Hydropower provides a stable energy supply, while wind and solar can be scaled to meet high energy demands. During periods of surplus wind or solar power, the excess energy can be diverted to hydrogen production. When these renewable sources produce less power, hydropower can step in to stabilize the grid.
This approach also creates seasonal energy storage capabilities. Hydrogen can be produced when renewable generation exceeds demand and stored for later use. This stored hydrogen can then be used to generate power or fuel industrial processes during low renewable energy periods.
Overcoming the Challenges: Cost, Infrastructure, and Policy
While green hydrogen offers a promising path forward, several key barriers must be addressed before it can be scaled to meet global demand. These challenges include reducing the cost of green hydrogen production, building infrastructure for hydrogen transport and storage, and creating supportive policies.
Reducing the Cost of Green Hydrogen
Currently, green hydrogen is significantly more expensive than hydrogen produced from fossil fuels (grey hydrogen) or natural gas (blue hydrogen). Several factors drive these high costs:
- High Energy Costs: Electrolysis consumes large amounts of electricity, making electricity prices a key determinant of hydrogen costs. Countries with low-cost hydropower are at an advantage.
- Electrolysis Technology: Existing electrolysis technologies are expensive, although advances are being made to improve efficiency and lower production costs.
However, with the rapid expansion of renewable energy and increased investment in hydrogen technologies, these costs are expected to decline. Falling renewable energy prices and economies of scale in electrolyzer production are projected to lower green hydrogen production costs over the next decade.
Building Hydrogen Infrastructure
After production, hydrogen must be stored, transported, and distributed to end users. Hydrogen, being light and low in energy density, presents several logistical challenges:
- Dedicated Pipelines: Building dedicated hydrogen pipelines is costly and will take time. Some existing natural gas pipelines may be retrofitted to carry hydrogen, but this requires significant modifications.
- Hydrogen Storage: Storing hydrogen is expensive. Options include compressing it into high-pressure tanks or liquefying it at very low temperatures. Both methods require advanced infrastructure.
- Ammonia as a Carrier: Hydrogen can be converted into ammonia, which is easier to transport and store. Ammonia can be converted back into hydrogen when needed, offering a practical solution for regions lacking hydrogen infrastructure.
The Need for Policy and Regulation
The transition to green hydrogen depends on strong government policies and regulations that support innovation and adoption. Governments can provide financial incentives, subsidies, and set emissions reduction targets to drive demand for hydrogen. Additionally, clear regulations around safety, hydrogen purity, and blending hydrogen with natural gas are needed.
Policy Examples
Countries like Germany, Japan, and the European Union have introduced hydrogen strategies that include significant public funding, infrastructure development, and carbon reduction goals. For hydrogen to reach its full potential, more nations will need to implement similar policies.
Conclusion: The Path Forward for Hydrogen from Hydropower
Green hydrogen produced via hydropower holds enormous potential to decarbonize heavy industries, offering a sustainable alternative to fossil fuels. Countries rich in hydropower resources are well-positioned to lead this shift, producing and exporting hydrogen on a global scale. However, significant challenges remain in cost, infrastructure, and policy support.
As technology advances, and with proper investment and regulatory frameworks, hydrogen can serve as a key component of the energy transition. Its combination with hydropower offers a pathway to decarbonize even the most energy-intensive industries, moving us closer to a sustainable, zero-emission future.