This document discusses using 66kV voltages for offshore wind farm array cables as a way to reduce costs. Higher voltages allow fewer cables to be used to connect turbines over long distances, reducing cable material costs and losses. The document presents analysis showing that converting three sample wind farms from 33kV to 66kV array voltages could reduce cable lengths by up to 45% and losses by up to 46%, demonstrating the potential cost savings of the higher voltage approach. It proposes a design for 66kV array cable systems and notes ongoing testing of these higher voltage cable arrays.

1. 66 kV Offshore Wind Farm
Wet design for higher voltage wind farm applications
Author: Aida Esther Reig Pérez
01/11/2015 Bremen

2. 2
Agenda
1. 1klj
1.Wind Farm Market Cable arrays
2. Use of higher voltages to decrease costs
3.Proposed design for 66 kV array cables
4.Testing for 66 kV array cable systems systems
5.Cable arrays future trends

3. 3
Wind Farm Market Array Cables
Dynamic Market
1. Wind turbines- increase of power
output: WTG from 3,45 MW up to
6-8 MW
2. Deeper waters with floating wind
turbines
3. Cost reduction for new offshore
systems:
1) Offshore Wind Accelerator (over
all system cost reduction by
10% for Round 3 wind farms)
2) Voltage increment from 33 kV
to 66 kV systems

4. 4
Is using 66kV for array cables really a cost reduction?

5. 5
Is using 66kV for array cables really a cost reduction?
Nº Application Voltage
(kV)
Power
(MW)
Power
(MW)
per WTG
Nº cables
to
Collecting
point
km of
cable
Losses
in array
cables
%
A Nearshore 33 186 3,45 5 96 100%
66 196 7 3 60 61%
B Nearshore 33 145 3,45 4 81 100%
66 147 7 2 47 52 %
C Offshore*) 33 531 8,3 14 171 100%
66 531 8,3 9 135 54 %
Estimated losses based on IEC 60287 values
Three scenarios of offshore windfarms:
*) “Offshore system” requires an export cable at higher voltage