Sustainability & CSR
Hydrogen: Hope or hype?
Hydrogen’s use in industry, transportation, power generation and storage could play a significant role in the transition to net zero but not without trade-offs and economies of scale
By Bart Linssen
The hydrogen energy system is a versatile and potentially zero emission energy framework that utilises hydrogen as a universal energy carrier. Hydrogen is produced from various sources, including renewable energy as well as from fossil fuels. Once produced, hydrogen can be stored, transported, and used in fuel cells or combustion to generate electricity and heat, with water being the only emission.
Hydrogen production
Hydrogen production for energy use can be achieved through several diverse methods, each with its own set of advantages, disadvantages, and cost implications.
Thermal processes
The most common method is steam methane reforming (SMR), which accounts for about 95% of current hydrogen production. This process involves high-temperature steam reacting with natural gas to produce hydrogen, carbon monoxide (CO), and carbon dioxide (CO2). While SMR is efficient and widely used, it relies on fossil fuels and generates significant CO2 emissions, although carbon capture and storage (CCS) can mitigate this issue.
Electrolytic processes
Electrolysis, which splits water into hydrogen and oxygen using electricity, is a cleaner and more sustainable method. When powered by renewable energy sources like solar or wind, this process produces "green hydrogen" with zero carbon emissions. Electrolysis is well-developed and commercially available, but its cost and efficiency depend on the cost of the electricity used. This method is particularly promising for applications requiring high-purity hydrogen.
There are several different electrolysis methods used to generate green hydrogen, each with its own characteristics and applications:
|
Electrolysis Technology |
Description |
Production Cost* (NT$/kg) |
Advantages |
Disadvantages |
|
Alkaline Electrolysis (AE) |
Uses a liquid alkaline solution as the electrolyte. |
NT$83-166 |
Established technology Lower capital costs Reliability Scalability to MW |
Lower efficiency |
|
Proton Exchange Membrane (PEM) |
Utilizes a solid polymer membrane, operates at lower temperatures. |
NT$124-171 |
High purity hydrogen Compact design Rapid response – best for wind and solar |
Higher capital costs Requires pure water Expensive catalysts |
|
Solid Oxide Electrolysis (SOE) |
Uses a solid ceramic electrolyte at high temperatures. |
NT$69-138 |
High efficiency Can utilise waste heat |
Still under development Higher maintenance costs |
|
Anion Exchange Membrane (AEM) |
Combines features of alkaline and PEM technologies. |
NT$97-152 |
Potentially lower costs than PEM Uses cheaper materials |
Less mature technology, still being optimised |
*A kilogram of hydrogen produces approximately 18kWh in a fuel cell.
Other processes
Besides thermal and electrolytic there are solar driven and biological processes under development that rely on photoelectrochemical or photobiological processes to generate hydrogen. However, they are currently not viable for large-scale production due to technological and efficiency limitations.
Green, blue, grey hydrogen
So called grey hydrogen is produced primarily through steam methane reforming (SMR) of natural gas. This process involves reacting methane with high-temperature steam to produce hydrogen and carbon dioxide. It accounts for about 95% of global hydrogen production but generates significant carbon emissions, with approximately 9-12 kg of CO2 emitted per kg of hydrogen produced. It is generally the cheapest form of hydrogen due to established production processes.
Similar to grey hydrogen, blue hydrogen is also produced via SMR but incorporates carbon capture and storage (CCS) technologies. This captures the CO2 generated during production and stores it underground. Blue hydrogen reduces emissions by up to 90% compared to grey hydrogen, but it still relies on fossil fuels as a feedstock. It is typically, more expensive than grey hydrogen due to the additional costs associated with carbon capture technologies.
Green hydrogen is produced using renewable energy sources (e.g., wind and solar) to power the electrolysis of water, splitting it into hydrogen and oxygen without emitting CO2. It is considered the cleanest form of hydrogen, producing zero emissions during its entire lifecycle. Currently more expensive than both grey and blue hydrogen, green hydrogen is projected to undercut blue hydrogen in price by the end of the decade due to the falling costs of renewables and economies of scale.
Finally, white hydrogen, as it is known, is found in natural deposits deep within the Earth’s crust. These deposits, however, are not sufficient to meet the global demand for this technology. In this case, the environmental impact of the element comes from the invasive and costly extraction methods.
Hydrogen transport
The transportation of hydrogen as an energy carrier presents several challenges and significant costs, which are critical factors in the development of a viable hydrogen economy. One of the primary issues is the energy-intensive process of liquefying or compressing hydrogen, which consumes a substantial portion of the energy content of the hydrogen itself. For instance, liquefying hydrogen leads to 10% energy losses, and additional energy is lost during transportation due to boil-off.
Pipelines are considered the most efficient and cost-effective method for transporting hydrogen over short to medium distances (up to 2,500-3,000 km), but the existing infrastructure is limited, with only about 2,600 km of hydrogen pipelines in the United States and 2,000 km in Europe. For longer distances, shipping hydrogen or using hydrogen carriers such as ammonia or liquid organic hydrogen carriers (LOHC) is more cost competitive.
However, these methods also come with their own set of challenges, including the need for specialized storage and handling facilities, and the high energy requirements for converting these carriers back into hydrogen.
Applications
Hydrogen, as a versatile and clean energy carrier, has a wide range of applications across various sectors, each with its own potential for growth.
Transportation
Hydrogen Fuel Cell Electric Vehicles (FCEVs) produce only water vapor and warm air as emissions, making them an attractive alternative to traditional internal combustion engine vehicles. FCEVs offer driving ranges comparable to or even exceeding those of conventional vehicles, often over 500km, and can be refuelled in as little as 3-5 minutes. This makes them viable for long-distance travel and daily use, similar to traditional petrol (gasoline) or diesel vehicles.
Hydrogen is also being integrated into various other types of vehicles. Companies like Toyota and Hyundai are developing hydrogen fuel cell technology for buses and heavy-duty trucks, which can significantly reduce emissions in public and commercial transportation.
Hydrogen fuel cells are also being used in industrial settings, such as forklifts, and in specialty vehicles like taxis and ride-sharing services. Hydrogen is often less efficient compared to established alternatives like battery-powered electric vehicles. The overall efficiency of hydrogen systems typically ranges from 25% to 35%, primarily due to energy losses during production, storage, and conversion processes. In contrast, battery electric vehicles can achieve efficiencies of around 90%. There was a significant increase in sales of Hydrogen Electric Vehicles from 2017 to 2021, peaking in 2022. However, sales dropped in 2023 and further declined in the first quarter of 2024. The decline in sales reflects challenges in the hydrogen vehicle market, including limited infrastructure and competition from battery electric vehicles (BEVs).
Aircraft
Hydrogen is a potential fuel for aircraft, offering the potential for zero emissions flight. Hydrogen can be utilised in two primary ways: through fuel cells that generate electricity for electric motors or by combustion in modified gas turbine engines. Challenges are the complexity of safely handling hydrogen due to its flammability. Furthermore, hydrogen's low density requires larger storage tanks, which could limit aircraft range and payload capacity.
Airbus and Boeing are both exploring hydrogen as a potential fuel for future aircraft, but their approaches differ significantly. Airbus plans to introduce a hydrogen-powered airliner by 2035, focusing on using hydrogen gas turbines for propulsion. Airbus is actively developing technologies to support this initiative, aiming to lead the industry in sustainable aviation solutions.
Boeing, on the other hand, remains cautious about hydrogen's feasibility for commercial aviation before 2050. The company cites safety concerns, technical challenges, and the need for significant redesigns of aircraft to accommodate hydrogen's larger volume and cryogenic storage requirements. Boeing has conducted various hydrogen demonstrations but prioritises sustainable aviation fuels (SAF), fuels made are made from used cooking oils, agricultural and forestry waste, as a more immediate solution for reducing emissions in the short term.
Power generation and energy storage
Hydrogen can be used in combined heat and power (CHP) systems and as a means to store renewable energy. When produced from renewable sources, hydrogen can help stabilize the grid by storing excess energy generated from solar or wind power. This stored hydrogen can then be used in fuel cells to generate electricity, heat, or power for various applications, including backup power systems and distributed energy solutions.
Hydrogen can be integrated into gas-fired power plants primarily through cofiring and conversion. Cofiring involves blending hydrogen with natural gas, which can reduce carbon emissions; for instance, blends of up to 30% hydrogen have been tested, achieving significant CO2 reductions. In addition, new gas plants are being designed to transition fully to hydrogen by upgrading turbines to handle higher hydrogen concentrations.
Future prospects
The future prospects for hydrogen applications in Taiwan are ambitious yet challenging due to several factors. Taiwan has committed to reducing greenhouse gases and achieving net-zero emissions by 2050. Key targets include increasing the share of power generated by hydrogen to 9-12% by 2050, as outlined in the Taiwan 2050 Hydrogen Application Development Technology Blueprint released by the Industrial Technology Research Institute (ITRI) in June 2022.
Despite progress, Taiwan faces substantial hurdles related to infrastructure and policy support. The country lacks adequate renewable energy resources to produce green hydrogen, relying heavily on imported hydrogen until local production capacities improve. There is a pressing need for robust policies, including subsidies, pricing mechanisms, and competitive market regulations to attract foreign investments and foster local innovation.
Countries like Japan and South Korea have advanced significantly in hydrogen technology and infrastructure. For example, Japan aims to complete its hydrogen infrastructure by 2040. Both nations have implemented comprehensive policies supporting the development of hydrogen ecosystems, including financial incentives and regulatory frameworks.
Based on current technology and costs, hydrogen is likely to find its primary applications in power generation, heavy industry, and potentially in larger vehicles requiring extended driving ranges, such as long-haul trucks that benefit from rapid refuelling. In contrast, for most other applications, batteries appear to be the more economically viable option. This perspective is supported by a recent Bloomberg report, which indicates that hydrogen will play a limited role in achieving global net zero targets.
Bart Linssen is the Director of Renewable Energy at RCI Engineering
