The requirement for an offshore reactive compensation substation is a direct consequence of wind farms moving further offshore. The Hornsea Project One offshore wind farm will be located in the UK, app. 120 km (75 mi) off the Yorkshire coast, and 180 km (111 mi) from its connection point on land. The 1,2 GW wind farm is expected to host 150 - 240 turbines and three HVAC substations. To reduce the power loss in the export cables, the reactive compensation substation is required midway of the export cable between the wind farm and onshore connection point.
The solution of mitigating the electrical power losses by implementation of a reactor platform halfway to the connection point on land is the first of its kind. In other wind farms far from shore in the North Sea, this has been mitigated by introducing the somewhat larger and heavier HVDC platforms and using DC power in the export cable.
As the high voltage set-up on the platform will be the first of its kind on an offshore substation, it will pose a number of interesting challenges for Ramboll’s team of offshore specialist engineers. The team will be looking at a number of solutions on how to best integrate the shunt reactors that will provide reactive power to reduce the electrical losses. This includes assessing different configurations of high voltage gas insulated switchgear. In addition, Ramboll will be designing the topside layout to include other utilities, mechanical equipment, SCADA systems, cable deck, laydown area, heli deck and emergency accommodation area etc.
The Hornsea Project One offshore reactive compensation substation will be standing in 23 m (75 ft) of water.
’The platform design will be conceptualized and designed in close collaboration with our client, and our team is looking forward to working with DONG Energy, who is an ambitious frontrunner within offshore wind farm development. It is our aim to conceive a cost-effective solution by focusing on design optimization and steel weight reduction. It is an important target, which can help reduce the overall cost of offshore wind energy,’ says Department Director, Peter Busch Nielsen.
Presently the concept, which is being considered, is a traditional steel jacket and topside.
The project will run until February 2016.
Hornsea Project One is located 120km off the Yorkshire coast and covers approximately 407 square kilometres. Hornsea Project One has a total capacity of up to 1.2GW, which will make it the world’s largest offshore wind farm once completed. The wind farm will be able to meet the electricity needs of around 800,000 UK homes.