Energy Delivery


The Energy Delivery tool is used to design the electrical infrastructure to transmit power from one or more ocean energy converters back to shore. It is one of the Deployment Design Tools, run after Energy Capture and Energy Transformation, but before Station Keeping.


This module’s documentation is divided into four main sections:

  • Tutorials that give step-by-step instructions on using Energy Delivery for new users.

  • How-to Guides that show how to achieve specific outcomes using Energy Delivery.

  • A section on background, theory and calculation methods that describes how Energy Delivery works and aims to give confidence in the tools.

  • The API reference section documents the code of modules, classes, API, and GUI.


The main purpose of the Energy Delivery tool is to design the electrical network to transmit power from devices to shore, including the:

  • Array network – cables between Ocean Energy Convertors (OEC). These are also referred to as intra-array cables, or inter-array cables.

  • Collection point (CP), which can be a substation with voltage transformation or a passive hub or a device.

  • Transmission (or export) cable to the Onshore Landing Point (OLP).

The design is based on user choices, design parameters from other tools, and a catalogue of typical electrical components. A simplified generic offshore electrical network for ocean energy arrays is shown in the figure below.


Fig. 74 Diagram showing scope of ED design, covering array network, collection point, and transmission system.

The main outputs are a network design, the energy and power delivered to shore and network losses, a total cost and bill of materials for the electrical components used, plus a hierarchy of how they are connected.

The Energy Delivery tool can either be run in simplified mode (complexity 1) or full detail mode (complexity 2/3). Note there is no difference in the design process between complexity 2 and 3, but these have been retained for consistency with other tools. This also allows the user to select a medium complexity level (2) if they are using surrogate data, for example flat bathymetry. For more information on levels of complexity within DTOceanPlus, please see Understand levels of complexity in DTOceanPlus.

The Energy Delivery tool is based on the Electrical Sub-Systems module in DTOcean v2.0.0 [DTO2], which has been ported from Python 2.7 to Python 3.6 and additional functionalities added.

Workflow for using the Energy Delivery module

The workflow for using the Energy Delivery module can be summarised as 1) provide inputs, 2) perform a design, and 3) view the results, as shown below.

Diagram showing high level process for ED: inputs, design, outputs

Overview of Energy Delivery data requirements

This section summarises the types of input data required to run the Energy Delivery module. Full details and data specifications are given in the how to guide on preparing data. The required and optional inputs to run the module are summarised in the tables below. Note that in integrated mode, the required inputs will all come from other modules except for the onshore landing point coordinates and network topology to be assessed.

Required inputs for the Energy Delivery module


Low complexity (1)

Full complexity (2/3)

Site characteristics

Bathymetry data and seabed material for both lease area and export cable corridor

Device characteristics

Device rated power (kW)

Device rated voltage (V)

Device technology: fixed/floating

Device rated power (kW)

Device rated voltage (V)

Array characteristics

Number of devices

Array spacing (m)

Distance to shore (m)

Onshore distance (m)

Coordinates of onshore landing point

Layout of devices in array as a json string of device coordinates (m, m)

Frequency of occurrence of array power output

Configuration parameters

Network configuration to be assessed

Summary of optional inputs for Energy Delivery


Low complexity (1)

Full complexity (2/3)

Device characteristics

Device connector type: wet-mate/dry-mate

Footprint radius

Device power factor

Location of device electrical connection, as (x, y, z) relative to device (m, m, m)

Device equilibrium draft without mooring system (m)

Array characteristics

Onshore infrastructure cost (€)

Array AEP or Capacity factor

Onshore infrastructure cost (€)

Electrical losses of onshore infrastructure, as percentage of annual energy yield

Max/min voltage limits (pu)

Configuration parameters

Predefined export system voltage

Maximum number of devices per string in radial configuration

Predefined burial depth of the array cable(s) and export cable

Maximum seabed gradient considered by the cable routing analysis

Cable installation method

Cable protection option

Maximum horizontal offset of device for umbilical design

Types of electrical components in catalogue




Static cables

Dynamic (umbilical) cables




Collection Points


Passive hub