Rampion Offshore Wind Farm

Talk – Tuesday 13th October 2015 ‘Rampion Offshore Wind Farm’
Mr Naren Mistry and Mr Richard Carpenter
Naren Mistry is the e.on Rampion Project Offshore Engineering Manager and gave an overview of the general and off- shore elements of the project. Richard Carpenter is the Onshore Cabling Contract Manager and covered the onshore elements.
General Following development consent by the Secretary of State on 16 July 2014 work commenced on the offshore wind farm project in July 2015. The Project is jointly funded by German utility e.on and the UK Green Investment Bank (GIB) and is expected to be operational in 2018.
Offshore The offshore element comprises the wind turbines and interconnecting cabling, the offshore power station and main supply cable to shore.
Foundations The foundations for each turbine are Grounded Monopile. These utilize a single, large-diameter, foundation structural element to support all the loads (weight, wind, etc.) of the turbine. Construction includes driving a large hollow steel pile 4 m in diameter with approximately 50mm thick walls, some 25 m deep into the seabed. A “transition piece” (complete with pre-installed features such as boat-landing arrangement, cable ducts for submarine cables, turbine tower flange, etc.) is attached and sand and water are removed from the centre of the pile and replaced with concrete.
Turbines There will be 116 (V112-3.45 MW) MHI Vestas Offshore Wind turbines in a regular grid matrix with a minimum spacing between the turbines of 750m with the nearest turbine to shore being 13km (8 miles). Each turbine has a capacity of between 3MW and 7MW giving an overall generating capacity of 400MW.The turbines are 85m tall to the hub height, and 140M to blade tip.
Inter-Turbine Cabling The UK Company JDR is responsible for designing, manufacturing and pre-commissioning the 142km of 36kV inter-array cables. They will also supply the hang-offs, electrical t-connectors, inner cone connectors, cable cleats and cable protection system for the project.
The Dutch company Fugro will be responsible for the installation and burial of the array cables using the construction and installation vessels Fugro Symphony and Fugro Saltire. A Q1400 trenching system will be used lay the cables.
Offshore Substation Babcock International are responsible for the design and construction of the 2500-tonne offshore substation platform topside and jacket at its facility at Rosyth. ABB will supply the offshore substations, plus “related power infrastructure”, such as medium-voltage switchgear, power transformers and protection and control systems.
The farm has an installed generating capacity of up to 700MW and is situated approximately 13 – 23km off the Sussex coast, together with an offshore and onshore electrical infrastructure, including a 26.4Km underground cable from the coast to a new substation situated at the 400Kv National Grid Substation near Bolney Mid Sussex.
Based on the current expectations of the area’s wind resource over the long- term, e.on estimate the site could generate more than 2,100 gigawatt hours (GWh) of electricity each year. This is enough to power the equivalent of around 450,000 homes, more than two-thirds of the homes in Sussex, including the city of Brighton and Hove.
Undersea Supply VBMS, a Netherlands company that specialises in subsea power cable installation will be responsible for the installation (lay and simultaneous bury) at a depth of 1.5 to 2.0m two 16 kilometre-long, 3 core aluminium, 150kV High Voltage Alternating Current (HVAC) export cables from the offshore substation to the onshore cable junction at Brooklands Pleasure Park using the DP2 cable-laying vessel Stemat Spirit.
Onshore The onshore elements comprise an Onshore Power Station being built as an “add-on” to the existing power station at Bolney, an Operations and Maintenance base at New Haven and the on-shore cable route. The cable route is designed to take account of the fact that the cable route passes through the South Downs National Park and other ecologically sensitive areas. Construction methods are being tailored to reduce impacts, one example being at Tottington Mount where there is sensitive chalk grassland.
Operations and Maintenance Base The base will accommodate up to 65 full time, permanent staff for the lifetime of the project (25 years) and will be the main project management hub during offshore construction.
On-shore Cable Route Carillion has been awarded the contract to design, supply, install and test the twin circuit 150kV cable system. The cable system will connect to the subsea cable from landfall near Shoreham-on-Sea to Bolney Substation, a distance of approximately 26km. The onshore cabling project has commenced and comprises 12 Stages. It is scheduled for completion in late 2016.
Cable laying will utilise the Ducting installation method with a Horizontal Directional Drill (HDD) being used for rivers, roads and railway.
Onshore Power Station Work commenced in June 2015 and be complete in December 2016. The construction comprises three main activities; civil and enabling works, mechanical and electrical build, and commissioning. The substation transforms the 150kV output from the offshore power station to 400kV for connection to the National Grid. ABB will supply the substation including high-voltage air-insulated switchgear (AIS), gas-insulated switchgear (GIS), transformers and substation automation as well as control and protection systems. The substation will also be equipped with four STATCOM (static compensator) units to ensure grid stability. These will provide reactive power compensation by detecting and instantly compensating for voltage fluctuations associated with the intermittent nature of wind energy.
Randy Keir