Pilot for o shore hydrogen production

Client Rijksdienst voor Ondernemend Nederland (RVO)

Platform operator

Neptune Energy

Facts

Type: PEM electrolyser

Nr. of Cell stacks: 1

Input power: 1 MW

Water consumption: 300l/h

Hydrogen ow: 246Nm3/hr

Hydrogen purity: 99.998%

Outlet pressure: 30 barg

Footprint: 2 x 40ft stacked containers

Lifting weight: <20 tonnes ( 2 x 20ft cont)

Cable: 9 MVA, 25kV

Production: 400 kg/day

The Q13a-A hydrogen pilot project aims to demonstrate green hydrogen production o shore, on a live oil and gas production platform. The lessons learned will help enroll large scale green hydrogen production on the North Sea. O

Right o the coast of Scheveningen (The Hague), the rst pilot for integration of three working o shore energy systems will take place on a working platform Q13, which is already electri ed with renewable energy via a cable to shore. The power from wind and demineralized seawater will be converted to green hydrogen o shore following the wind pro le of Eneco’s Luchterduinen wind park. The green hydrogen will be blended with natural gas and transported via existing pipelines. Existing infrastructure thus will be co-used. The production of the platform is expected to start end 2023.

Iv-O shore & Energy works together with several PosHYdon consortium partners to create a safe environment to handle hydrogen (and oxygen) on a live oil and associated gas platform.

Technical limitations of co-production of hydrogen and North Sea gas, sea water desalination, power uctuation and electrolyser performance will be addressed.

Other consortium partners will identify and address requirements related to permitting, certi cation and entry specs. A logistic and training and competencies gap analysis will be made. Economical calculations are made: how to maintain value of hydrogen while admixed with natural gas? Economics will be taken into account for large scale hydrogen production o shore.

Iv-O shore & Energy is responsible for the basic and detailed engineering of the necessary adaptions to the platform to host the electrolyser system, is involved in the risk assessment and mitigation and brings o shore expertise. Iv-O shore & Energy also provided the list of o shore requirements for the containers with the electrolyser, the seawater desalination system and power conversion system.

In order for the hydrogen production system to be tested onshore, few adaptations need to be ensured: power connection, su cient space for the system, supply of (sea)water, disposal of brine, hydrogen use/ release, oxygen release, permits to test and permits to construct.

Iv-O shore & Energy prepared a conceptual document describing the system interfaces and further requirements on the adaptations and modi cations which need to be taken care onshore.

Floating transformer platforms

Client Internal R&D project

Technical data

Dimensions: 85 x 85 x 30 m

Weigh

Topside: approx. 11,000 mT

Floater: 10,000 mT

Water depth

Over 150 m

Worldwide, the best wind conditions for generating wind energy are often found at sea in areas with deeper waters. The question is: how can this be achieved as effciently, reliably, and affordably as possible? At water depths beyond 150 metres, the costs of the renowned ‘bottom- founded’ structures (such as transformer and converter platforms and wind turbines that are anchored to the seabed via a structure) increase exponentially, making floating solutions an interesting option. Iv-Offshore & Energy and Nevesbu jointly developed a concept for an offshore substation. A concept with potential!

Studies show potential

Iv-Offshore & Energy and Nevesbu consistently carry out innovative studies. In view of the oncoming energy transition, Nevesbu began investigating which unique floating applications could be devised to provide a solution. There are already many concepts for floating turbines, but not for a floating substation. We formed a joint initiative as Iv-Offshore & Energy has already designed many offshore wind substations, and Nevesbu has specialist knowledge of floating structures. The challenges presented with this type of floating solution include the lifespan of the dynamic power cables and the allowable motions of the transformers, rectifiers, and associated systems. Floating an offshore converter station weighing roughly 10,000 tonnes with minimal motions is a complex challenge, but our studies show that it is possible.

In Europe, the Mediterranean, North Sea, Bay of Biscay, and the Aegean Sea, in particular, are deepwater areas that are very suitable for generating wind energy. Especially in the area above Scotland and the United Kingdom towards Norway and Denmark, there are almost continuous strong winds. The concept that Iv-Offshore & Energy and Nevesbu have developed is therefore designed for the harsh weather conditions that are characteristic of these areas. The concept also minimises the impact on marine life.

Design principles

Some essential principles for the design of the floating transformer platform are: the concept must conform to the set requirements for wind energy at sea, it must not be too heavy in steel weight and must not be complex in terms of fabrication, safety, and reliability must also be guaranteed, it must be possible to guarantee a very high availability, and the platform must have a lifespan of at least 30 years. In addition, the social costs of supplying sustainable electricity must remain affordable, and the solution itself should therefore not be too expensive in terms of costs.

From static to dynamic

The most significant challenge is the transition from a static bottom-founded platform to a dynamic floating platform. Wind turbines must be capable of operating in conditions up to Beaufort 8, which means that the floating platform must continue to function when contending with waves of 8 to 12 metres high. Existing high voltage (HV) equipment, however, is not suitable for high accelerations. To guarantee motions are kept to a minimum, motion analyses were carried out to calculate how different models behave at sea in strong winds with high waves. These analyses are based on the roughest seas in the world, such as the North Atlantic Gulf Region, the Bay of Biscay and the sea near Santa Barbara, California. If the concept is suitable for these waters, it can certainly also be applied in calmer waters.

The concept of the floating platform is designed in such a way that it can be applied in water depths in excess of 150 metres and with minimal vertical motions in sea conditions. The HVDC platform has a deck area of 85 by 85 metres and is positioned approximately 20 metres above the water’s surface. When the platform is installed at sea, it will be held in position with the help of so-called ‘tendons’ that are vertically anchored to the seabed. The floating structure is designed to minimise the vertical motions, which also reduces the loads on the export cables suspended below the platform. Tuning the motion behaviour of the platform for different water depths and wave conditions is also relatively simple.