Basically there are 3 types of Wind Farm contracts commonly used:
- Supply only. It include WTGs, SCADA, Installation supervision and Commissioning.
- Supply and Installation, including all the items in Supply only plus WTGs transport and cranes for the installation (basically, it adds the assembly of the machine).
- Turnkey (full EPC), including all the above plus civil and electrical works.
What is EPC?
Engineering, Procurement and Construction (EPC) contracts are the most common form of contract used to undertake construction works by the private sector on large-scale and complex infrastructure projects.
Under an EPC contract, a contractor is obliged to deliver a complete facility to a developer who need only “turn a key” to start operating the facility, hence EPC contracts are sometimes called turnkey construction contracts. In addition to delivering a complete facility, the contractor must deliver that facility for a guaranteed price by a guaranteed date and it must perform to the specified level. Failure to comply with any requirements will usually result in the contractor incurring monetary liabilities.
Engineering: A detailed engineering project is developed to fit the machines to the actual conditions of the site. Conditions can vary dramatically, depending on topography, geotechnical conditions, grid connection requirements, permits, local regulations an so on. In this phase technical choices are made, and drawings are produced together with the bill of quantities.
Then comes the Procurement phase, where civil and electrical works are subcontracted to one or more companies. Potential subcontractors are contacted, their quotations are received and compared. Short listed contractors are screened and the work is finally awarded to the company with the best price/quality ratio.
Finally, the phase of Construction begin, where the works of the subcontractors are monitored to see if they comply with the technical specification and if there are delays respect to the signed chronogram.
What is BOP?
BoP stands for Balance of Plants. In the wind farms sector, it means everything but the wind turbines. The sum of wind farm civil works and electrical works are usually called Balance of Plant (BoP).