EPZ (Elektriciteits Produktiemaatschappij Zuid-Nederland) the Electricity Production Company South-Netherlands, the operator of the coal- and nuclear power plants located in Borssele in the Netherlands.
OVET – Terminal Port Administrator in Vliessingen, administrating coal storage area
Senvion S.A. (called REpower Systems SE until 2014) was a German wind turbine manufacturer founded in 2001 in Germany, delivering the full EPC supply including the 2 x 6M turbines.
The customer approached REpower to deliver a full EPC turn-key project at a harbour location, in the middle of a coal storage area, an area administered by OVET an external 3rd party company. This consisted in the first challenge, install big 6M turbines and perform infrastructure works (access, transport, craning, cabling, foundations) in the middle of a densely covered area with huge 50m height pills of coal and administered by a 3rd party. Any clearance of space would not only take days but also have a considerable financial spending for project. The ground had a covering layer of asphalt for protection of underground infiltration and pollution. Any work needed to critically manage soil pollution risk. One of the biggest challenges however was to plan the execution of the wind farm works around the daily normal operation of the harbour / coal power plant, any project setback could jeopardize the energy delivery of the power plant. Electrically there was also a considerable risk in connecting two (2) powerful turbines to the somehow “weak” 30 kV harbour grid, it could affect the cranes and other used heavy machinery, even the testing of the turbines could impact the stable operation of the entire harbour and power station. On top of all these challenges, it was REpower`s first full scope project with BoP outside of Germany entirely managed by an internal team. The challenges and risk were big as the project moved into execution.
When our customer approached us the challenge was quite clear. Our job consisted in supporting him with a solid, safe design and planning, and execute perfectly. Our team managed the engineering design both civil and electrical, and provided the customer for a basis for a safe planning. On the engineering side the tasks included works specification, tendering, negotiation, contracting. On the project management side the tasks included planning coordination, execution supervision and final taking over.
To minimize impact and risk, the plan consisted in making just enough space between the big pills of coal for the unavoidable access, foundation work and crane assembly, thus minimizing impact inside critical coal area. The plan also considered safeguarding the existing protective asphalt layer, therefore planned for directional underground drilling for the cable trenches. 3 holes over 400m each were necessary to turbines, station and even power an auxiliary building nearby. Long PVC ducting works were performed outside critical area, and then pulled into final position in 1 attempt. Medium voltage, communication, low voltage power supply cables would would then be installed into the PVC ducts. The station and grid operation parameters were carefully evaluated and selected with the local grid operator (Delta), so that testing and operation ramp up had minimal impact on local grid stability.
Implement on site daily activity coordination as at times more than 5 subcontractors would need to work in parallel inside the critical area, and confined space.
The choices made during design enabled a solid planning a good start into execution. It helped our customer keeping the coal power plant operating and minimized the impact on OVET`s moving pills of coal. During drilling the team faced last minute uncertainties as exact information about dept of old buried cables and the risk of drilling through them arose. The results could have been disastrous and the impact on the harbor area and project huge. Still the team managed with help of local sub-contractor knowledge to overcome that barrier and managed the uncertainty. There were minor schedule delays due to whether (snow, rain and ice) conditions but finally the project was successfully installed and both turbines and power plant could operate stability. Mostly important our customer celebrated the great achievement of installing 2 big turbines in the middle of a coal yard and manage to bring it successfully into full operation.