To Keep Cooling Costs Under Control a Few Large Data Center Users Follow the Moon

Follow the moon to control cooling costs?
Follow the moon to control cooling costs?

A data center professional at a large global enterprise recently shared that that they’re evaluating a “follow the moon” strategy, designed to limit the expenses of data center cooling. It had been a while since the phrase had been shared with us, which is indicative of some changes in the data center world.

Following the moon refers to a global enterprise shifting loads from continent to continent based on time of day in order to reduce cooling costs. During the daylight hours in North America they’ll shift as much load as possible overseas. During nighttime hours in the US they’ll transfer the bulk of the activity of their overseas users to their US data center. An east coast/west coast North American strategy is utilized by some to geographically concentrate load to capture advantageous off-peak power rates.

Some users go back and forth between primary and disaster recovery based on time of year, having their production data center in the cooler hemisphere for half the year and then reversing as the seasons change. Such a strategy can be pursued by an organization with data centers, for example, in Brazil and the US. But following the moon involves pursuing a similar strategy on a daily basis based on day part, not season.

Following the moon isn’t discussed much these days for a few reasons. More large enterprises have built data centers with efficient cooling in mind. By utilizing free air cooling as much as possible and designing for reduced power consumption, there is less of a need to make sacrifices elsewhere.

There’s also more of a focus on being close to the end users, so it is unlikely that a company delivering video and other media is going to want to be half a world away from their consumers.   Additionally, the costs of operating a large data center are diminishing as more facilities rely on redundancy at the application layer, an assumption that eliminates the need for expensive redundant power infrastructure.

With servers and other IT infrastructure now designed to withstand higher temperatures, cooling as a share of operational expenses is lessened. The ability to keep a data center at 80 degrees offers considerable savings over the need to maintain a 72-degree environment.

Given the changes in the data center world, to hear of an enterprise considering a strategy of following the moon harkens back to a different time. But for one global enterprise, a team of smart people is seriously considering it again. We’ll stay in touch with them and see if we can get them to share their decision as well as the thinking that led to it.