Home furnishing superstore Ikea says it will stop selling incandescent light bulbs in its U.S. stores by about the end of the year, and it will start pulling them from shelves in August. The Swedish company has its North American Headquarters near Conshohocken.  It says the voluntary phase-out is aimed at increasing energy efficiency and reducing carbon dioxide emissions by offering customers Compact Electronic Fluorescent bulbs, LED’s and Halogen lamps, which save energy by providing more illumination for the dollar and lasting much longer than incandescent bulbs.