Bradley Corp.'s light-powered nditeÔ technology is just one of many “green” building techniques built into an experimental Wal-Mart Supercenter in Aurora, Colo.

Bradley Corp.'s light-powered ndite[tm] technology is just one of many “green” building techniques built into an experimental Wal-Mart Supercenter in Aurora, Colo.

The new system only needs to use restroom lighting to power the company's ExpressÒ SS and MG series of lavatory systems. Photovoltaic cells, integrated into the top of the lavatory system, capture the light and store the energy without needing batteries. As a result, the system does not require electrical hook-ups.

The Wal-Mart store includes about 50 various energy-efficient ways to conserve power. For example, the store also uses used motor oil and cooking oil to fire two separate boilers that provide partial snowmelt and radiant heat. The Colorado store is the company's second such building, and Wal-Mart officials say they hope to incorporate what works in the two stores into its vast retail empire.

“We want to be on the cutting edge of green technology,” said Don Moseley, Wal-Mart's director of experimental projects, during a media preview in November, “not the bleeding edge.”