Examenspresentation av Enrique Van Dyke Del Moral

Master Thesis conducted at Hitachi Energy, under the supervision of  Tarik Dervisic
Opponents: Almasbek Ayaz and Anup Aryal

A Teams link to attend the presentation online is provided:
Meeting ID: 395 748 684 305
Passcode: VchSAX) 

Abstract 
Climate change is one of the most pressing issues that humanity faces today. The urgent need to mitigate greenhouse gas emissions has triggered an unprecedented expansion of renewable energy sources, consequently, creating an opportunity to revolutionize our energy systems. In this context, green hydrogen emerges as a potential candidate to decarbonize hard-to-electrify industries, such as iron & steel, petrochemical, maritime transport, and aerospace. These sectors rely either on fossil fuel-derived chemical compounds or require high-density fuels that exceed the capabilities of batteries.

Currently, the most mature and standard technology to produce green hydrogen is through electrolysis, as long as its electricity mix comes from renewable sources. This process involves splitting water molecules into hydrogen and oxygen, and storing the first one as energy carrier. This thesis presents an overview of different electrolyser technologies and focuses on the most developed and available in the market. 

The electrolyzer model will be connected to a distribution system, either HVAC or medium voltage DC. Medium voltage DC systems should be implemented for direct production from solar and wind power plants, skipping the rectification stage and using fast-dynamic electrolyzer technologies (PEM) required to harness the intermittent power flow. HVAC systems for standard industrial facilities for cost savings and standardization. It is essential to match electrolyzer’s technology with adequate electrical infrastructure. 

Due to time constraints, it is only proposed plant structures for HVAC system connection, the subsequent converter selection and implementation. The chosen topology is a 12-pulse thyristor rectifier with an alkaline electrolyzer as load. There is a dedicated chapter to study the converter-load interaction and this design is scaled-up in later sections to reach higher power levels. 

At the heart of the green hydrogen revolution lies the concept of producing it on a gigawatt scale, which will come necessary to make it cost-competitive with fossil-fuel alternatives like steam-methane reforming. Just as the mass production of wind and PV technologies have significantly reduced their costs and allowed pioneers to learn valuable lessons through a "learning by doing" approach, electrolysis is bound to follow a similar path. 

This thesis endeavors to explore the technical feasibility of green hydrogen production at a gigawatt scale by examining several proposed plant designs, implementing reversedengineered models of electrolyzer products available in the market and identifying barriers like grid code requirements. Therefore, proposing solutions to those issues and evaluating strategies to decrease costs in the electric infrastructure of large-scale plants.

Welcome! 

Enrique, Tarik & Massimo