USD 7-digit losses after only 4 years of operations of 18MV PV plant - due to low quality
VDE Renewables was tasked to look at a 18 MW PV plant featuring central converters in the UK after performance of the system started declining after only 4 years of operations.
Inspection of the PV plant determined that the DC transmission cables were buried directly into the ground, but the cables were not rated for this type of application and started to fail. The remediation required 5km of trenches to be dug up and 66km of new and properly-specified cables to be put in place.
A key lesson learned by the plant owners was that a comprehensive assurance assessment (which includes cable-related checks) conducted before the project was commissioned. could have prevented the high remediation costs.
Comparing costs: The costs for cable replacement was about EUR 1.5 million. Only EUR 60k would have been required at an earlier stage of the project to avoid a cost of EUR 1.5 million after 4 years. However, even after 4 years the investment of EUR 1.5 million was a good investment to fix the plant as any more year of operations would have increased the losses for the plant owners.