Technical Due Diligence - Process

In the first step Technical Due Diligence includes a detailed Document Review

• The design basis for the original wind farm design should be provided as a pre-requisite.
• The assumptions, provisions and conclusions outlined in the wind site assessment report as well as in the soil condition assessment report will be evaluated and compared to the issued certificates and site specific design verification reports.
• The wind turbine evaluation will focus on track records for the wind turbine, certification status and fitness for the site. The track record for the particular wind turbine type(s) will be valuated. For existing wind farms, the actual track record for the specific, individual wind turbines in the wind farm will also be assessed.
• For existing wind farms, the records of maintenance, repairs and inspections carried out will be reviewed and verified against the approved maintenance manual and program
• Evaluation of the expected net annual energy production from individual turbines as well as for the whole wind farm. For existing wind farms the expected net annual energy production will also be compared with actual operation data. In the second step extensive site inspections will be carried out to verify the wind turbines comply with approved design and required maintenance programs.

All wind turbine components will be checked

• Rotor including blades and hub assembly
• Mechanical transmission including gear boxes
• Nacelle and tower structure including connections
• Generators, converters and transformers
• Control and protection systems
• Electrical systems
• Lifting appliances
• Personnel safety installations

Special focus will be laid on

• Fatigue cracks
• Dents and deformations
• Corrosion
• Bolt pre-tension
• Status on outstanding points from previous surveys
• Settings and parameters used by the control system
• Cooling media and lubrication (if applicable), in our own testing laboratories
• Witness test of the control and protection system (carried out by the manufacturer or operator)
• Condition monitoring system
• Additional surveys identified based on findings and deviations, e.g. witnessing of tests and inspections in order to distinguish between random and systematic failures

The above range of services will be tailored to suit the actual verification needs in the project.