Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With these methods, an ingot can be grown that is low in carbon and whose crystal growth is controlled to increase the cross-sectional area of seeded material during casting.
 This application was made with U.S. Government support under Subcontract No.: ZAZ-6-33628-11 under prime contract with the National Renewable Energy Laboratory awarded by the Department of Energy. The Government has certain rights in this invention.