July 3, 2008 - A green-design dilemma: Wal-Mart and Costco have debuted a new gallon-size milk carton that cuts energy costs by saving space in refrigerators and shipping trucks - but consumers say the jugs just don't stack up to the old version, the New York Times reports.

Sam’s Club, owned by Wal-Mart, estimates that the new boxy shape of the container cuts shipping labor by half and water use by 60 to 70%. The new shape also does away with the need for milk crates. Sam’s Clubs can now store 224 gallons of milk in the same coolers that used to hold just 80.

All these energy savings have not gone unnoticed at the check out line, either. A gallon of milk in the new container at Sam’s Club now costs $2.18 down from $2.58 in the old jug style.

These savings do not seem to have won over customers yet, who are unhappy with the new shape saying it is messy to pour and difficult for kids to use. Early negative consumer reaction to the re-design could defeat the entire push for greening fluid milk and highlights a much larger issue in design - that green designs have to work as well or better in order to get buy-in from consumers.

The introduction of the new container is the latest in an overall move to reduce the carbon footprint of milk. The dairy industry recently committed to greening milk production and distribution, including how it is packaged. And there already appears to be plenty of room for innovation in this area.

But with the cost and energy savings Wal-Mart and Costco are seeing, the companies are spending no time crying over customers’ spilled milk choosing to instead show them how to effectively use the new containers with in-store demonstrations. To these companies streamlining every part of design, manufacturing, and transportation of a product is part of the future of tackling sky-rocketing energy costs.

However, surveys indicate that even green-minded consumers won't buy if it isn't convenient.

For SLM green-marketing guru Jacquelyn Ottman's take on the "green consumption gap," click here.