US retailer Wal-Mart has rolled out a new store prototype, billed as its greenest ever and expected to save up to 45% more energy than the baseline Wal-Mart Supercenter.

The new store prototype, called HE 5, features advancements in heating, cooling, refrigeration and lighting to conserve energy and reduce greenhouse gas emissions, the company said.

This includes a system to reduce the temperature of water by pumping it through roof-mounted cooling towers, and then running the cold water underneath the retail floor to cool the shopping area.
 
Wal-Mart said that the prototype will only be built in regions with a suitable climate.