Apparatus and methods are provided for manufacturing cast silicon. The systems and methods include a plurality of inductive coils configured to form a space to contain molten silicon, and configured to generate an electromagnetic field when an electrical current is supplied to the inductive coils to support the molten silicon so that a gap is maintained in a portion of the space between at least one substantially vertical wall of the molten silicon and at least one of the inductive coils, and when a portion of the molten silicon solidifies into a solid silicon ingot as the molten silicon is cooled by the cooling device, a concave liquid/solid interface is formed between the molten silicon and the solid silicon ingot.
 This invention was made with U.S. Government support under National Renewable Energy Laboratory (NREL) Subcontract No. ZDO-2-30628-03 under Department of Energy (DOE) Contract No. DE-AC36-98GO10337, awarded by DOE. The U.S. Government has certain rights in this invention.