Key concepts
Key concepts for realizing the potential of offshore wind
Hub-and-spoke
The evolution is ongoing: From near-shore radial alternating current (AC) connections to far offshore direct current (DC) connections. The hub-and-spoke concept is another step in this evolution, adding interconnection and potentially electricity conversion.
Traditionally, separate electrical connections were used to connect wind farms to shore on the one hand (wind farm transmission), and to connect countries to each other on the other hand (interconnection). In a hybrid project such as the proposed hub-and-spoke, there are electrical connections from the wind farm to multiple countries. This combines the two functions and the connections are used more efficiently.
Together with international cooperation, hybrid projects play a key role in integrating the planned large-scale deployment of offshore wind in Europe.
Different hub-and-spoke configuration
The future system needs long-term flexibility: the ability to deliver electricity at a time when it is not sufficiently produced by renewables. Renewable electricity can be converted to green hydrogen, which supports integration in a variety of different ways.
Through a combination of elements, electrolysis supports a larger and more useful roll-out of offshore wind generation compared to a situation without electrolysis.
Understanding Power-to-X
Power-to-X in its most basic form means electrolysis of water to produce hydrogen. This can be done offshore, in which case salt needs to be removed from the sea water through a desalination process. It is possible to transport both electricity and hydrogen to shore.
Power-to-X means converting electricity to another energy carrier. In our definition this includes hydrogen, synthetic fuels (liquid and gaseous) and chemicals. These renewable products enable us to decarbonise energy users that currently need fossil fuels, including chemical companies.
Societal Cost Benefit Analysis
A societal const benefit analysis (CBA) is used to assess the costs and benefits of a project to society. Comparing the results of different alternative projects to a reference case allows to identify the project that results in the highest benefits compared to cost to achieve a certain goal, e.g. large-scale integration of offshore wind.
A societal CBA requires a clear set of guidelines to consistently evaluate alternative projects. These include guidelines for the definition and scope of project alternatives, the reference case, the geographical scope of analysis, the cost and benefit indicators that should be evaluated, the definition of scenarios and the tools and assumptions to use for calculations.
