  Digital Twins bring several benefits for planning, operation, and maintenance
of remote offshore assets. In this work, we explain the digital twin concept
and the capability level scale in the context of wind energy. Furthermore, we
demonstrate a standalone digital twin, a descriptive digital twin, and a
prescriptive digital twin of an operational floating offshore wind turbine. The
standalone digital twin consists of the virtual representation of the wind
turbine and its operating environment. While at this level the digital twin
does not evolve with the physical turbine, it can be used during the planning-,
design-, and construction phases. At the next level, the descriptive digital
twin is built upon the standalone digital twin by enhancing the latter with
real data from the turbine. All the data is visualized in virtual reality for
informed decision-making. Besides being used for data bundling and
visualization, the descriptive digital twin forms the basis for diagnostic,
predictive, prescriptive, and autonomous tools. A predictive digital twin is
created through the use of weather forecasts, neural networks, and transfer
learning. Finally, digital twin technology is discussed in a much wider context
of ocean engineering.
