wind. However, the North Sea offers opportunities not only for large-scale wind energy production but also for hydrogen production and underground CO2 storage. The North Sea is currently the most visible place of the energy transition. Offshore gas will still be an important component over the next few years but will be coming to an end over the next few decades as fields become depleted. At the same time, offshore wind is growing exponentially in all countries surrounding the North Sea. By 2030, offshore wind parks should be able to provide the Netherlands with 11.5 GW of clean but intermittent power. This intermittency is due to the variation of wind speed being too low or too high. There is also
Figure 1. The electrolyser units for hydrogen production will be placed on the top deck of the Q13a-A platform, with crane access.
the question of whether the national grid can handle all of this renewable offshore energy. Although TenneT, the transport system operator for the Netherlands, is working hard to upgrade all infrastructure, the chances are that wind turbines will need to be curtailed around 2030, wasting extensive renewable energy. As standalone sectors, both the electron-based and molecule-based parts of the energy system are facing challenges. It is time to look closer and think smarter by integrating these two sectors. With this line of thinking, existing and producing platforms could be converting the surplus of renewable wind energy into green hydrogen, storing it in depleted gas fields, and transporting it when needed via the existing gas infrastructure to the onshore grid. Trunk pipelines can handle a higher volume of molecules at a lower transportation cost compared to power cables, and they are already in place. For example, a 36 in. trunk pipeline can handle more than 10 GW of pure hydrogen, meaning there is no need for extra cables, extra investments, or to stir up the subsurface with potential damage to the marine ecosystem. This requires working together across sectors towards integrated energy systems, linking the electrons and molecules. The North Sea Energy Program is a platform that brings all players in the offshore North Sea world together to combine knowledge and fast-forward projects through studies, research, pilots, and demos. Wise connections will reduce carbon emissions, reduce costs, make effective use of offshore space, preserve nature, and accelerate the energy transition. Good co-operation and co-ordination will enable opportunities to be seized, put the North Sea on the map as a pioneering region for the European energy transition, and provide an example to other regions of the world.
The pilot project
Figure 2. Schematic explanation of the hydrogen production process from desalinated seawater. Oxygen is safely disposed of.
Figure 3. The green hydrogen produced will be admixed with the oil and gas stream via the existing gas infrastructure.
14 ENERGY GLOBAL SUMMER 2020
The key to unlocking the potential of integrating offshore energy systems is the PosHYdon pilot, a pioneering project to create the first offshore green hydrogen production plant in the Dutch sector of the North Sea. Under the scheme, three energy systems will be integrated on one platform: offshore wind, offshore gas, and green hydrogen. The pilot was commissioned by Nexstep, the Dutch Association for Decommissioning and Re-Use, and TNO, the Netherlands Organisation for Applied Scientific Research, in close collaboration with the industry. On 4 July 2019, Neptune Energy’s Q13a-A platform was selected as the pilot's location. Neptune’s Q13a-A platform is located near the Dutch coast, 13 km from The Hague. The platform is well-suited for this project. As the first fully electrified offshore oil platform in the Dutch North Sea, it saves approximately 16 500 tpy of CO2 – equivalent to 115 500 flights from Amsterdam, the Netherlands, to Paris, France. A proton exchange membrane (PEM) electrolyser will be placed within a sea container and installed on the platform. It will convert seawater to demineralised water through reverse osmosis and use green electricity from offshore wind to produce hydrogen. The electrolyser will have a minimum
