A method of making a solar grade silicon wafer is disclosed. In at least some embodiments of this invention, the method includes the follow steps: providing a slurry including a liquid that essentially prevents the oxidation of silicon powder and a silicon powder that is essentially free of oxides; providing a solar grade wafer mold defining an interior for receiving the slurry; introducing the slurry into the solar grade wafer mold; precipitating the silicon powder from the slurry to form a preform of the solar grade silicon wafer; and crystallizing the preform to make the solar grade silicon wafer.