We are keeping track of the temperature & comparing the difference between Houghton and Detroit as the project was originally intended to be sited there.
When we worked with students from the ME Department at UMich they researched the temp and found it didn't get cold enough in Detroit to maintain a large block of ice for the length of time needed to stay frozen. Clicking this link will download their design document to your computer (a 70 pg. pdf) if you'd like more information. Their research is one of the reasons we were convinced to move further north . . .