Challenges and Innovations in Green Hydrogen: A Pathway to Sustainable Energy Transition

Executive Summary

Green or low-carbon hydrogen is seen as a potential energy resource integral to drive energy transition to achieve global net-zero ambitions. An integrated approach to drive sustainable development goals opens new pathways in green hydrogen applications in industries, utilities and transport sector. My paper examines green hydrogen’s journey towards a sustainable future, by catalyzing global net-zero ambitions, from production to impact. The paper explores how innovations and advancing technology in green hydrogen can help us achieve not just a green fuel alternative of the future, but also build long-term energy security. The paper also discusses the best practices and use cases in the production, transportation and use of green hydrogen, their impact on the economy and society, and the risks and challenges in the adoption of green hydrogen economy.

Introduction

The immense potential of green hydrogen, produced by RE-powered electrolyzers, in low-carbon energy transition is a foregone conclusion.  Green hydrogen can be used as a fuel for less-carbon power generation by blending with natural gas in gas turbines. This can be a buffer to meet the energy demand during intermittent solar and wind generation. It can be used as an industrial feedstock, for example, in the production of green ammonia and nitrogenous fertilizers. In transportation, green hydrogen can be used as zero-emission fuel for fuel-cell electric vehicle (FCEV). It is also a clean energy substitute for fossil fuels in heating applications. Therefore, green hydrogen shows a promising pathway to accelerate sustainable energy transition and fight climate change. However, the use on green hydrogen to decarbonize our industry, transport, electricity and heating has its own challenges. The most pressing challenges are the high cost of infrastructure, production, storage and transportation, while balancing capacity and safety. Policy and regulatory support for green hydrogen infrastructure creation, and promoting green hydrogen technologies, e.g. fuel cells, electrolyzers, blending, safe storage and transportation, can help address these challenges.

Challenges in Green Hydrogen Production, Storage and Transportation

Green Hydrogen is produced through an electrochemical process called electrolysis, where water is split into hydrogen and oxygen. The pros and cons of each of these technologies to produce green hydrogen is enumerated below:

1. Proton Exchange Membrane (PEM)

• Pros: High efficiency, clean production.
• Cons: High initial and production costs, membrane durability issues.

2. Alkaline Water Electrolysis

• Pros: Lower cost, well-established technology.
• Cons: Lower efficiency compared to PEM.

3. Solid Oxide Electrolysis Cells (SOEC)

• Pros: High efficiency.
• Cons: High operating temperatures, material challenges.

4. Photo Electro-chemical (PEC) water splitting

• Pros: Utilizes solar energy
• Cons: Poor efficiency, sluggish reaction rates.

5. Biological and Microbial Electrolysis

• Pros: Sustainable, can use organic waste.
• Cons: Lower production rates, complex processes.

6. Hybrid Technologies

• Pros: Combines multiple techniques to enhance production and sustainability.
• Cons: Complexity, integration challenges.

Storage and transportation pose a challenge for green hydrogen pertaining to safety issues. While hydrogen can be compressed and stored, its storage requires ultra-high compression and costly refrigeration. Overcoming economic and technical hurdles of hydrogen storage and transport is critical to exploit its potential as an energy carrier. Various storage methods for hydrogen are:

1. Compressed Gas Storage: Hydrogen is stored in high-pressure tanks at pressures up to 700 bar.

• Pros: Simple and widely used method.
• Cons: Requires strong, heavy tanks and high energy for compression.

2. Liquid H₂ Storage: Hydrogen is cooled to cryogenic temperatures and stored in insulated tanks.

• Pros: Higher energy density compared to compressed gas.
• Cons: Significant energy required for liquefaction and specialized insulated tanks to maintain low temperatures.

3. Metal Hydrides: Hydrogen is absorbed into metal alloys, forming metal hydrides.

• Pros: Safe and compact storage method.
• Cons: High cost of metal hydrides and slower release rates.

4. Chemical Storage: Hydrogen is stored as chemical compounds, such as ammonia and hydrocarbons.

• Pros: High storage density and ease of transportation.
• Cons: Requires chemical processing to release hydrogen.

5. Underground Storage: Hydrogen is stored in underground caverns or depleted oil and gas fields.

• Pros: Large-scale storage capacity.
• Cons: Requires suitable geological formations and infrastructure.

Innovative Use Cases in Green Hydrogen

Green Hydrogen technologies offer a promising pathway to achieve sustainable energy goals. The merits of these technologies are evaluated in terms of hydrogen production efficiency, purity, cost, availability and sustainability. Listed below are few innovative use cases in green hydrogen, aimed to enhance its production and use, contributing to clean energy, emission reduction and sustainability:

1. Hydrogen Fuel Cells (HFC): HFCs can fill the gaps in electricity demand during intermittent generation from renewable energy systems.  Fuel cells also find applications in sustainable transport operations by sea, land, or air, minimizing carbon footprint and promoting a green economy.
2. Renewable Hydrogen: Production of green hydrogen from renewable energy sources eliminates carbon emissions. This can be achieved through electrochemical, photocatalytic and thermochemical means.
3. Hydrogen intermediates: Hydrogen intermediates having low carbon emissions e.g. e-methanol can be used in internal combustion engines by blending with motor fuels.
4. Carbon Capture, Utilization & Storage (CCUS): CCUS technology is used to sequester CO₂ emissions from steam reforming of natural gas to produce blue hydrogen. The carbon captured is stored, processed and used as industrial feedstock.
5. Combined Heat & Power (CHP): Green hydrogen blended with natural gas act as low carbon fuel for gas turbines in power generation. Termed cogeneration, the exhaust heat from gas turbines is fed to the boiler to produce steam, for electricity generation and heating.
6. Hydrogen Propulsion: Green hydrogen is used as a clean propulsion fuel (liquid oxygen-hydrogen systems) in aviation and space applications. Blending it with other fuels provide a low-carbon alternative to polluting fossil fuels.

Role of technology in green hydrogen transition

Technology plays a key role to enhance the efficiency, reliability, and sustainability of green hydrogen production and use in industrial, transportation and utility applications, making it a viable alternative to substitute fossil fuels and contribute towards global energy transition. For example:

1. Artificial Intelligence and Machine Learning (AI/ ML): AI/ ML helps in enhancing green hydrogen production efficiency, storage optimization and real-time decisions, e.g.:

1. Optimizing Operations: AI algorithms can optimize electrolyzer operations by analyzing real-time data from sensors and adjusting parameters such as temperature, pressure, and current to improve efficiency, performance and increase green hydrogen production.
2. Predictive Maintenance: AI-powered predictive maintenance systems monitor asset health and detect potential issues in electrolyzers, compressors, pumps, and other components of green hydrogen production, storage and distribution to reduce maintenance costs.
3. Optimizing RE sources: AI/ ML application can help optimize the use of RE sources for green hydrogen production by forecasting energy generation from wind, solar and other renewables, considering factors like weather forecasts, grid demand, available capacity and energy prices.
4. Supply Chain Optimization: AI analyzes supply chain data to optimize logistics, transportation, storage and supply of green hydrogen, apart from managing resources in a cost-effective way. 

2. Industrial Internet of Things (IIoT): IIoT plays a crucial role in the green hydrogen economy by enabling real-time monitoring, control, and optimization, for example:

1. Real-Time Monitoring and Control: IIoT devices, such as sensors and telemetry, provide real-time data on energy consumption, plant performance, hydrogen production and storage.
2. Enhanced Efficiency: IIoT systems facilitate the integration of RE sources to power electrolyzers for green hydrogen production, with real-time data of availability, production and storage. 
3. Data-Driven Decisions: IIoT enables data-driven decisions by providing accurate forecasts of variable RE generation and energy demand, thus optimizing resources and cost of production.

3. Blockchain: Blockchain technology offers a secure, transparent, and decentralized way to manage transactions and track emissions in the green hydrogen value chain, for example:

1. Certificates of Origin: Blockchain can simplify the certification process for green hydrogen by providing a secure and immutable digital ledger to store transactions. This ensures traceability and verification of green hydrogen origin from clean energy sources.
2. Smart Contracts: Blockchain enables automated execution of smart contracts among parties for transacting in green hydrogen, without a central authority or intermediaries. 
3. Transparency and Security: Blockchain provides a transparent and secure way to track emissions and green molecules along the value chain from production to consumption. This helps stakeholders efficiently account for and track emissions, ensuring that investments in green hydrogen are appropriately credited.

4. Digital twins (DT): Digital twins are virtual replicas of physical systems that can simulate, predict and optimize real-world processes. This is applied in green hydrogen production to model variables e.g. weather, demand, cost and infrastructure, to maximize returns and minimize risks, for example:

1. DT modelling helps to calibrate optimal configuration of RE systems and electrolyzer capacity, based on hydrogen production demand and storage capacity.
2. DT simulation monitors the operations of electrolyzer and associated equipment to predict potential failures, reduce downtime and maximize production efficiency.

5. Advanced analytics: Analytics can transform data into business intelligence with actionable insights, during green hydrogen production, for example:

1. Analytics of data from green hydrogen production and storage facility helps in timely corrective action to maximize yields.
2. Data analytics helps in analysis of operations to increase electrolyzer uptime, reduce losses and improve revenues.   

Conclusion

Green Hydrogen is recognized as a net-zero carbon combustion product, making it a sustainable alternative to traditional fossil fuels. It is increasingly being adopted across sectors, including industries, transportation, decentralized power generation, aviation, and shipping, due to its environmental benefits and other advantages. Unlike conventional energy sources, green hydrogen offers a way to store and transfer energy without emitting harmful pollutants, positioning it as a clean fuel for a sustainable and net-zero future. It offers clean, efficient power on demand through combustion engines, blended gas turbines or fuel cells. Hydrogen can decarbonize some of the most challenging industrial sectors, such as steel and cement, energy production and transport. Technologies such as AI/ML, IIoT, Blockchain, Digital Twins, and advanced analytics can optimize operations, maintenance, resource allocation, supply chain, and data-driven decisions in green hydrogen production and its applications.