Amazon’s data center efficiency honcho James Hamilton penned a recent blog post in which he argued that while there’s been a dearth of great engineering ideas lately for improving data center power consumption, collocating a desalination plant next to a data center has some definite synergies.

For those not following the devastating California drought, it’s in its third year and in many municipalities customers are being asked to reduce their water use. Smart water metering is being discussed and desalination is making a comeback as a solution to dealing with droughts.

Desalination has its critics, from environmentalists who argue that the water pumping destroys marine life to consumer groups concerned about the expense of desalinated water. Desalination is very energy intensive since water must be pressurized and run through filters. It’s expensive water.

But Hamilton’s argument has to do with the benefits of locating a data center next to a desalination plant. Why? Well pumping cool ocean water through a data center first and thus cooling the data center, before the water heads to the desalination plant, would provide benefits for both data center and desalination plant. The data center effectively gets cooled for free minus the power costs of circulating the water while the desalination plant gets warmer water, which lowers its energy cost in desalinating ocean water.

There have been other synergies suggested with data center siting. One idea that has been presented has been to locate a data center near a district heating system and using the heated water for that system. We don’t have much district heating in the U.S. but in Europe it’s more common.

What continues to impress me about the upper echelon of data center innovators (Amazon, Facebook, Google, Apple) is that they keep looking for engineering innovations. If only that were true of the cultures at other major energy hogs like manufacturing facilities and commercial real estate.