New Wal-Mart store cuts energy costs by 45%

Unsurprisingly, retail giant Wal-Mart is the largest private user of energy in the world. So it's pretty interested in using less energy, especially when that garners good publicity.

At a new store in Las Vegas, Wal-Mart has installed advanced, low-energy roof-top fluid coolers. These use the surrounding air to cool water, which is then pumped into pipes below the store's floor. The resulting cooling completely eliminates the need for air conditioning and, in Las Vegas, that's a huge amount of a store's energy cost.

One problem though, Las Vegas doesn't really have very much water to spare and, unfortunately, these fluid coolers rely on evaporating away many gallons of hot water to leave the cold water, for cooling, behind.

In hot areas with plenty of water, this seems like it would make a lot of sense. But in Las Vegas, where the city is pretty certain to be out of water in 10 or 20 years, this might not be the best solution.

Via the AP