ABB has unveiled its thyristor-based water-cooled UNIREC H2 power rectifier as far as green hydrogen production is concerned, which it claims will help operators cut energy losses and operational costs as projects enlarge. The UNIREC H2 multi-pulse thyristor rectifier converts AC electricity from the grid into the high-current DC power needed by electrolyzers, achieving power conversion efficiency of almost 99.6% at nominal current.
The units are configurable for almost 7.5 MW of DC power and 6 kA of output current. The modular architecture accommodates hydrogen plants spanning from megawatt-scale installations to projects over 1 GW.
Even minor enhancements in power conversion efficiency for large hydrogen plants may result in significant decreases when it comes to electricity consumption and operational costs. Power-conversion efficiency is a key factor for lowering the levelized cost of hydrogen – LCOH since electricity is roughly 60-70% of the operating cost when it comes to electrolytic hydrogen production.
Sarah-Xiaolan Huang, Global Product Manager for UNIREC H2 at ABB’s Energy Industries division, said that “electricity consumption is fundamental to the economics of green hydrogen, and as hydrogen projects expand, customers need power solutions that combine high efficiency and reliability with scalable architecture. UNIREC H2 is designed to help reduce energy losses while providing a reliable DC power platform for large-scale hydrogen production.”
The launch comes as the hydrogen sector searches for enhancements in project economics to underpin larger-scale deployments. In 2025, the International Energy Agency – IEA published that global demand for hydrogen exceeded 100 million tonnes, whereas low-emission hydrogen production increased by 20% to nearly 1 million tons. Installed electrolysis capacity more than doubled over 2025, thereby exceeding 4 GW.
It is worth noting that UNIREC H2 is a part of the wider approach by ABB for electrification of hydrogen plants. ABB can support customers beyond power conversion from early-stage plants along with power supply assessment to comprehensive design, assisting with electrolyzer configuration, rectifier selection, power architecture, energy storage, and quality of power energy efficiency. Electrical studies, simulation, and plant controls are then able to be utilized to optimize the energy use throughout the whole production system, not just the rectifier in isolation.
According to the Global Business Line Manager for Power Reliability at ABB’s Energy Industries division, Danilo Moresco, “Making better use of electricity is central to helping green hydrogen production scale. UNIREC H2 is designed to reduce energy losses at the point of power conversion, but the opportunity goes beyond a single piece of equipment. By looking at power architecture, controls and energy optimization across the plant, we can help operators make more effective use of every megawatt available.”
UNIREC H2 is built for uninterrupted, high-current industrial operation, enabling gigawatt-level production to provide bulk baseload power for applications where lowering the levelized cost of hydrogen and bankability are paramount. Its simplified architecture removes standard wear parts like electrolytic capacitors, and its standardized modular power stacks allow for future growth along with long-term operation.