System Overview

The overview of the charging system is shown in Figure 1 which includes, but is not limited to:

  • On turbine/ offshore substation power converter – converts the windfarm medium voltage AC power into DC power that is compatible with the CTV propulsion & battery system
  • On turbine mooring/charging cable & connector deployment system ‘Reeler’
  • Vessel connection & mooring system
  • Control & safety system

Real Time Control & Safety System

The real time control system is provided to enable safe control of the charging system from both the vessel and windfarm control room and is designed to embed safety throughout the charging process.

The control & safety system has been developed according to marine classification society rules and standards, using MJR Power & Automation’s 25 years of experience of designing and delivering safety and mission critical systems to the commercial marine and offshore energy industries. A real time deterministic marine grade operating platform is combined with the added functionality of a web portal system used for the booking and monitoring of the wind turbine charging system from the vessel, the windfarm control room and via desktop access.

The control software has been developed for fully automatic, semi automatic and manual control of the charging and vessel connection system to provide maximum flexibility. The high-level control modes are as follows:

  • Manual Control
  • Follow Mode
  • Mooring Mode
  • Positioning Mode

Throughout the process of charging the vessel battery system, vessel personnel have full visibility of the status of the charging and deployment systems from the operator control station that is situated on the bridge of the vessel.

An interactive, touch screen interface provides vessels with full control and visibility of the charging.

Web Portal

The web portal supplements the real time control system on the vessel and the turbine/offshore substation and allows asset owners and operators to access live data and analytics. It provides a means of booking, managing, authorising and remote real time monitoring of charging operations together with energy usage metering, carbon saving and emissions reduction data and billing. It also shows live information on vessel traffic, position and the status of the wind farm turbine chargers.

The secure web-based portal can be reached through mobile devices and desktop computers by users with the correct access privileges and complies with the latest DNV rules for Cyber Security. We appreciate that in a marine environment charge booking, authorisation and operations may be preferred to be carried out by VHF radio communication between the vessel and the windfarm control room. However, the offshore charging portal remains fully relevant in this case as it provides full desktop access to both real time and historical operational data, analytics and reporting.

Booking System

A booking system via the app or website provides similar functionality to other familiar online booking platforms, whereby the vessel looks for a free charging slot and books it. With the current functionality, the windfarm control room must authorise the booking before the vessel can connect to the charger, however the industry may prefer other functionality. It may be desirable that the functionality is similar to land-based EV charging whereby the vessel approaches the charger and is auto authorised unless the account is blocked.


A screen showing the vessel at the turbine charger and connected to it. This screen displays the vessel position relative to the turbine in real time and the key charging data and system performance parameters.