An unseen but important part of a wind project is transporting the power created from a turbine to the point of interconnection with the local grid. These photos were taken at Gundersen Health System’s Cashton, WI, wind project.
The turbine foundations at this site were poured, cured, and backfilled in November, 2011, in preparation for a spring delivery of the turbines. This avoided costly winter construction and assisted the project with a quicker construction cycle once the turbines arrived. When the foundations were ready, the power collector system and substation upgrade began.
A late and mild winter allowed trenching for the collector system cable to occur in December, 2011. These cables are buried below the frost line 4 to 5 feet underneath the surface. Proper design specifications and methods were followed to ensure that the electrical system would be robust and have appropriate safety features. Particular attention was paid to proper system grounding, power monitoring instrumentation, and minimizing the possibility of leaks or “stray voltage”.
Once a turbine is erected the power created from the generators is sent down the tower to a pad mount transformer which raises the power to a higher voltage. It will then be sent through cables to the point of interconnection which is usually a substation on the local distribution or transmission system. At the substation, the power is “stepped-up” once more to a voltage that matches the local grid requirement. Also at that point, the power is metered for payment by the interconnecting utility customer.
Gundersen Envision can help you with renewal energy projects. Learn how at www.gundersenenvision.org.