Let the drilling begin!

For the next three weeks, the contractor will be drilling the wells that constitute the geothermal field. Each of the more than 50 wells will be 150 feet deep to reach the area under the surface that maintains a constant temperature throughout the year. That constant temperature is the reason geothermal heating/cooling works.

I have always thought of these wells as similar to water wells as in "Timmy fell down the well," but now I wonder about the diameter of the wells. Does anyone know the diameter of these wells? I am curious.