Maikel van der List, instruments & control systems engineer at McDermott, delivered a presentation within the projects conference stream of Emerson Exchange EMEA 2024 that `explored the potential of large-scale offshore green hydrogen production’.

As the demand for hydrogen increases, it is necessary to scale up green hydrogen plant designs to the gigawatt scale. Van der List explained that one of the main advantages of offshore green hydrogen production is the availability of more consistent and stronger wind resources, which can be directly connected to hydrogen production in that location. Unlike onshore production, offshore production does not require expensive infrastructure such as offshore HVDC substations or large volume of subsea cables to collect and transport electrical energy to shore. Additionally, offshore production can help to reduce the visual impact of renewable energy infrastructure on land. Due to the inability of the existing electrical grid in the western part of Europe to support numerous hydrogen projects, offshore production near renewable wind energy sources will become necessary for countries in that region, such as the Netherlands, Denmark and Germany.

However, offshore green hydrogen production also presents some challenges. The cost of building and maintaining offshore infrastructure can be higher than onshore, and the harsh marine environment can increase maintenance costs and reduce the lifespan of equipment. Additionally, the transportation of hydrogen from offshore production sites to onshore markets can be more complex and expensive.

Currently, there are no large-scale green hydrogen installations operating offshore. However, there are several projects under development. In the Netherlands, for example, the Dutch government recently announced that it is to hold a tender for a 500MW green hydrogen production in the North Sea that will possibly use the existing natural-gas pipe belonging to the network operator Gasunie. The European Commission has said that it wants to develop the North Sea as a green power plant for Europe, targeting offshore wind power generation of at least 65 GW by 2030 and 150 GW by 2050. This expansion will facilitate large-scale offshore production of green hydrogen, with a target of 20 GW production capacity by 2030.

There is a need for innovative solutions that address the challenges of offshore hydrogen production, and van der List explained that McDermott is ideally placed, with significant experience in both onshore green hydrogen production and offshore complex process platform engineering designs. Offshore production is considered technically feasible, and van der List introduced delegates to a 480 MW capacity green hydrogen concept design developed to provide an initial framework for efficient and sustainable offshore green hydrogen production. The design is based on having the hydrogen production platform positioned in between a wind farm and 2GW HVDC platform. Through a detailed study, McDermott has determined that a centralized platform solution is preferable due to its lower cost and simplified logistics and operations. A split platform design (process platform and separate utility platform) with a bridge link offers more manageable size and weight.

A key part of the concept design is enabling the platform to operate autonomously. The journey towards autonomous operation starts with the automation of critical processes and maintenance, with a range of technologies such as pervasive sensing, predictive maintenance, asset performance monitoring and operational analysis then applied to optimize performance. To enable semi-autonomous operation with some human confirmation requires the use of state-based control, digital twin technology, simulation modeling, process optimization, and planning and scheduling software. Utilizing advanced operational analytics, artificial intelligence and machine leaning enables fully autonomous operation with human intervention by exception only.

McDermott is working with Emerson and AspenTech to assess a range of automation technologies and software that can ensure efficient and autonomous process control over the long term. These include advanced tools such as wireless vibration monitoring, root cause failure analysis templates, data integration technology, an advanced analytics platform for process unit optimization and asset performance, and enterprise asset performance management, monitoring and optimization solutions.

Van der List was keen to point out that autonomous operation is not just dependent on these technologies, and the readiness of the operator, in terms of procedures and work processes, is very important. When moving towards higher levels of autonomous operation there must be clear definition of what needs to be achieved, as well as the operator’s expectations and assumptions. A roadmap must define how to reach high levels of automation operation.