Does anyone know what the tax credit covers for geothermal systems installed in 2009?  I'm building new and looking at a geothermal heating and cooling system.  I plan to have forced air and radiant heat in the basement and garage. 

I'm wondering what is eligible for the tax credit. 

The geothermal unit itself, the wells, ductwork, electrical work, floor tubing, etc? 

Anyone with some knowledge please reply, I  have been searching for answers but not finding any.

Thanks,
c_in_nd