08.05.2018 | Operations at the "Axpo" Global Tech I wind farm
The Global Tech I offshore wind farm is located in the North Sea, 140 kilometres off the German coast. Axpo holds a one-quarter interest in Global Tech I. At the core of the facility is a transformer substation equipped with a cafeteria, infirmary and sleeping quarters. The installation is manned round the clock with a crew of up to 38 operations, service and assembly technicians.
Strong winds and rough seas today. Foamy white waves crash against the yellow pipes that are anchored to the sea floor by means of suction cups at the Global Tech I transformer substation. Up on the green and grey steel platform, a man braces himself against the wind while carrying out an inspection. His bright yellow and black work clothes are visible in the distance as we approach by helicopter.
We are out in the midst of the Global Tech I wind farm located over 140 kilometres from the logistics centre in Emden. The platform, weighing 9000 tonnes, is the core of the plant and also serves as the offshore logistical base. And it has been equipped accordingly. The living quarters can accommodate up to 38 operations, service and assembly technicians, who live, work, and sleep in single cabins (shared bath) in 2-week shifts.
The platform is a "small autarkic town" that includes its own hotel, a hospital with paramedics and telemedicine, a fire department, and a heliport and filling station. In addition to sleeping and common areas with a TV and a "Töggelikasten" (table football), a fitness room has been provided. A vitality coach visits the platform regularly and coaches workers on sports and work place ergonomics.
«The platform is a small autarkic town»Global Tech I
A radio mast on the transformer substation ensures maritime and TETRA radio communication as well as mobile telephony. Communication with the operations control centre on land takes place in real time by means of fibre optics. The Global Tech I team ensures the functioning of the electronic systems and is responsible for operations on the transformer substation. One task is generating fresh water from seawater with the desalination and wastewater treatment plants.
The service technicians working for the turbine manufacturer Adwen are responsible for service and maintenance on the wind power plants. Boats and helicopters transport workers from the transformer substation to the turbines, where they can quickly carry out their work without losing time.
All wind farm data is collected at the transformer substation control centre in order to monitor the wind plants, electrical systems and weather
The 155-kilovolt substation is the interface to the transmission grid. TenneT, the transmission grid operator, retrieves the electricity at Global Tech I by means of two export cables
Approximately 10,000 litres of seawater are desalinated and de-mineralised on a daily basis in order to provide fresh water for the crew and the equipment
The platform operations technology includes a wastewater treatment plant that processes and disposes of used water
The four transformers convert the three-phase current from the wind plants from 33 to 155 kilovolts for onward transport. The configuration is redundant
There are also women at work on the platform, for example, the Lithuanian woman working on the catering team. Breakfast and two warm meals (noon and evening) are served in the mess hall. The team is also responsible for housekeeping on the platform, and provides cleaning and laundry services. All these amenities are a must for the crew that puts in 12-hour days on 14-day shifts.
The Global Tech I offshore wind farm, in which Axpo holds 24.1 per cent, includes 80 turbines with a capacity of 5 MWs each, equalling a total of 400 MWs. (More in the adjacent article).
A new concept was developed for the Global Tech I transformer station using a closed structure platform. It houses all the equipment for the wind farm’s grid connection, and protects components from the aggressive, salty environment. Topside comprises several decks: The working deck holds a crane, a container storage area for spare parts, and a heliport. Living quarters with sleeping and common areas are also located here. The central control station and generators for self-supply are located on the main deck. The cable deck with the transformers and high voltage switchgear is located below the main deck.