Lake Turkana Wind Power project – the grid connection

Frederik Groeman

DNV KEMA Energy & Sustainability

Frederik.Groeman@DNVKEMA.com

Overview

• Background

• The wind farm

• Electrical collection system

• Grid connection

• Transmission grid expansion

Background

• Lake Turkana Wind Power is developing a 300 MW wind farm near Lake Turkana

• Grid connection needed to supply the generated power to Kenya Power across a >400km distance

• The connection point is near the wind farm

• The grid connection has been developed in parallel to the project

Development of the transmission line and substations

• As the first party to be connected to the line, LTWP, together with KPLC, KETRACO and the Ministry of Energy, have started to develop the Loiyangalani and Suswa substations and the transmission line up to tender evaluation

• KETRACO have taken over the lead and contracted the substations and the transmission line

• DNV KEMA supported originally LTWP, later KETRACO as owner’s engineer

Lake Turkana Wind Farm

• Laisamis District (Marsabit)

• 300 MW wind farm

• 365 Vestas V52 WTG

• Connects to new KETRACO “Loiyangalani” 220(400) kV substation

Electrical collection system of wind farm

• Large area

• Overhead collection network ~150 km

• Block size 100 MW

• Substation with step-up transformers, reactive power compensation, switchgear, metering and control systems

• Redundant design

• Loss optimization

Grid connection

• Connection point is at Loiyangalani substation at 220(400) kV level

• Double metering system

• SCADA interface for control and monitoring of the wind farm

Transmission grid expansion

• Transmission line Loiyangalani-Suswa 220(400) kV

• Suswa 220(400) kV substation

• Loiyangalani substation 220(400) kV

Transmission line Loiyangalani-Suswa

KPLC/KETRACO planned for a transmission line from the new Suswa substation to Loiyangalani:

• Connection of Lake Turkana Wind Farm

• Connection of geothermal power plants in the Rift Valley

• Strengthening the distribution grid and rural electrification of the Rift Valley along the route

• Ethiopia HVDC to terminate at Suswa

New Suswa substation

• Expected high demand growth in Kenya

• Planned extension of geothermal generation at Olkaria and other sites

• Planned Lake Turkana Wind farm

• Connection point for Ethiopian HVDC interconnector

KPLC/KETRACO constructs a new 400/220kV substation near Mount Suswa, also as part of the Nairobi Ring project

Design considerations for transmission line and substations

• The Kenya grid may not survive 300 MW trip on an outage

• Hence, the substations are fully redundant with 1½ breaker systems

• Also, the transmission line was designed as a double-circuit line with proper mechanical safety factors and good lightning performance

• Specific attention to loss optimization

• Specific attention to lightning performance

Transmission line: features

• 428 km length double-circuit transmission line for full redundancy with steel lattice towers, composite insulators and ACSR conductors

• Design rating 400 kV, initial operation at 220 kV proposed (same was applied to Mombasa line)

• Double OPGW for maximum communication redundancy

Suswa substation

• 1½ breaker design

• 1 reactor bay

• 2 capacitor bank bays

• 14 line bays

• Central control building

• Focus on high reliability

• Space for extension (HVDC)

Loiyangalani substation

• 1½ breaker design

• 2 line bays

• 3 bays for the power plant

• Central control building

• Focus on high reliability

• Space for extension

2 more substations planned

Near Rumuruti and Maralal

Status

• Contract for the substations has been closed

• Suswa 220 kV substation under construction, completion expected in May 2014

• Loiyangalani 220(400) kV substation contracted, Notice to Proceed expected soon, completion expected summer 2015

• 400 kV Transmission line contracted, Notice to Proceed expected soon, completion expected end 2015

www.dnvkema.com