Green hydrogen is a clean energy carrier produced by splitting water molecules through an electrochemical procedure called electrolysis. What makes it “green” is that it uses renewable electricity (unlike its "grey" and “blue” counterparts, which are powered by fossil-based energy), and boasts a clean production process, generating only water vapor as a byproduct. With electricity representing the majority of production costs, unlocking the potential of green hydrogen hinges on maximizing energy efficiency. 

Optimizing power for green hydrogen production

Electrolysis is an energy-intensive process. The efficiency with which an electrolyzer converts water and electrical energy into hydrogen directly impacts the overall cost and sustainability of green hydrogen production. Electrolyzers require a direct current (DC) power supply to function. However, the electricity generated from renewable sources like solar and wind is typically alternating current (AC). Technologies called rectifiers bridge this gap by converting fluctuating grid voltage and frequency into a steady DC supply, ensuring consistent and efficient power delivery to the electrolyzer.

The resulting hydrogen can then be stored efficiently – as compressed hydrogen gas, in liquefied form, or converted to ammonia or methanol – to be used later, for example in fuel cells that provide electricity when renewable sources are unavailable. In essence, green hydrogen acts as a kind of battery, storing renewable energy and enabling grid stability with a high penetration of clean energy sources.

In addition to rectifiers, variable-speed drives (VSDs) play a significant role in green hydrogen production. VSDs power pumps in water treatment plants to deliver ultra-pure water to electrolyzer arrays and control centralized water-cooling systems. They are also used to run compressors efficiently, refrigerating and liquefying the hydrogen gas produced.

Today's drive technology offers precise torque and speed control to optimize the performance and efficiency of motors, along with capabilities to smooth out fluctuations in the power supply and help overcome the intermittent nature of solar or wind-powered grids.

With green hydrogen, backed by rectifiers and VSDs, one of the biggest barriers to renewable adoption – intermittency – is far more manageable. Green hydrogen is therefore not just a mechanism for storing and moving energy, but a driver of renewable energy uptake.

An example of ABB’s work in this space is the HyPilot project, the green hydrogen pilot underway at the Gassco-operated Kårstø Gas Processing Plant in Rogaland, Norway. 

Technology innovations and green hydrogen

ABB offers a wide range of green hydrogen solutions, spanning grid and plant infrastructure, high-efficiency motors for pumps and pipelines, instrumentation, leak detection systems, fuel cells and more.

Our focus on integrating automation and digital systems allows for the real-time monitoring and control of various parameters within a hydrogen plant, such as temperature and pressure. This allows for proactive maintenance, preventing unplanned downtime and ensuring the smooth operation of the site, while minimizing energy consumption.

ABB Ability™ OPTIMAX®, a sophisticated energy management system designed to optimize the entire hydrogen production process, enables operators to identify inefficiencies and implement corrective actions. By leveraging advanced analytics and predictive modeling, OPTIMAX® optimizes energy flow, integrates renewable energy sources and manages energy storage assets for maximum efficiency. This holistic approach to energy management is crucial in reducing production costs – by as much as 20 percent – and accelerating the commercial viability of green hydrogen.

The role of green hydrogen in decarbonization

Perhaps the greatest benefit of green hydrogen lies in its ability to decarbonize those segments of the economy that can be difficult to electrify directly, often referred to as "hard-to-abate" sectors. These sectors, including heavy industry (e.g., steel, cement) and transportation (e.g., long-haul trucking, shipping, aviation) are major contributors to global greenhouse gas emissions.

While electrification is core to the energy transition, it's not always a practical solution for these sectors due to limitations like battery range for heavy-duty vehicles or maritime shipping, or the extremely high temperatures required in some industrial processes. Here, green hydrogen serves as a clean and versatile alternative energy carrier. It can be stored and transported efficiently, such as in fuel cells to power heavy-duty trucks and ships. In industry, it can replace fossil fuels for high-temperature processes or be used as a clean feedstock in various production cycles.

Highlighting the versatility of green hydrogen as a clean fuel source, ABB's traction system technology is powering the FLIRT H2, the first hydrogen-powered train in the United States.

Footnotes

1 https://www.iea.org/reports/global-hydrogen-review-2023