For five years, Google has been holding onto a patent for a data center design that would allow the center to be cooled by ocean water. The company may finally be using the patent, as investigative reports seem to suggest that Google is building data centers in California and Maine.
The buildings at these sites, while not explicitly connected to Google, are being constructed by a company that does have links to Google. Since the centers are adjacent to Treasure Island in the San Francisco Bay and off the coast of Portland, Maine, they are technically in international waters and free from government interest, if Google is looking to protect its data
Google's patent from 2008 detailed how a data center could be housed on a ship and its servers could be perpetually cooled by the ocean water. This sort of design is not only expensive to implement but it is also difficult, which may be why it has taken years for Google to actually use the patent.
Not only would the sea water cool the servers, but the ocean currents would also totally power the data centers, making them the most environmentally-friendly in the world. This is important, especially as data centers are now using nearly 2% of all the electricity in America.
Although other rumors on the structures being built near Treasure Island and Portland suggest they are floating Google Glass stores, that seems unlikely. Joel Egan, of Cargotecture, told technology publications that a store requires large open spaces, therefore the small "cubbies" of shipping containers would not be very useful when housing a store and allowing people to look around. Again the store idea seems unlikely when you take into account the locations -- opening a groundbreaking and unique store in Maine does not make much sense if Google wants to attract as many people as possible.
These reports are based around pictures and information regarding multi-story structures currently being built in Portland and near Treasure Island. Both of the structures are four-stories tall and they are almost the same size and shape, meaning that they are probably being built for the same reason.
A marine engineer told CNET that he had been working on a data center around the same time that Google applied for and attained its patent. He went on to say that the mystery structures look very similar to what he was working on. As a result, it seems extremely unlikely that the buildings will be retail stores, but rather, they fit Google's data center patent for its data center.
No matter what the mystery structures being built upon barges near San Francisco and Portland, they are almost definitely Google's and the idea that they will be used for data centers seems plausible. With the structures themselves already built, we should know what they will be used for within the coming year.