Windmill Project - Atlantic County Utilities Authority
Overview:
• Project consisted of the construction of five 1.5 MW wind turbines capable of supplying electrical power to 400 households each.
• Cost per windmill including premium costs of foundations: $2.5M.
• Return on investment over an expected life of 25 years
• Currently, the Atlantic County Utilities Authority satisfies its operational needs using wind and solar energy.
• Excess power is sold back to the grid in order to cover maintenance costs and finance initial investments.
Geotechnical Considerations:*
The Problem:
Subsurface conditions were unusually unsatisfactory for support of the 381-foot high windmill towers with approximately 150 diameter propellers. Granular fills over former wetlands overlie highly compressible organic deposits extending to depths of approximately 43 feet below existing surface grade. The basal geologic formation, the Cohansey, occurs at depths ranging from 65 to 70 feet below existing grade.
Our Solution:
Twenty-four Cast In-Place 14-inch diameter steel piles on a 10% batter providing approximately 450 kips axial capacity and 68 kips uplift capacity per pile on a 46-foot diameter circular configuration.
* Geotechnical work on this project performed by EGS Associates whose staff are now with CME Associates