Google builds its own servers to cut costs, and because standard products don't meet its needs.

Hardware makers invest heavily in researching and developing reliable products, a feature that most businesses value.

But Google doesn't actually need very reliable servers because it has designed its software to compensate for hardware outages, said Urs Holzle, senior vice-president of operations at Google, a company which is usually very discreet about the technology powering its data centres.

Instead of buying commercial servers, at a price that increases with reliability, Google builds less reliable servers at a lower cost, knowing that its software will work around any outages. "For us, that's the right solution," Holzle said.

Another reason that Google builds its own servers is equally simple: it can save costs on power consumption.

Energy efficiency is a subject Holzle speaks passionately about. About half of the energy that goes into a data centre is lost as a result of technology inefficiencies that are often easy to fix, he said.

The power supply to servers is one place where energy is unnecessarily lost. One-third of the electricity running through a typical power supply leaks out as heat, Holzle said. That's a waste of energy, and also creates additional costs in the cooling necessary because of the heat added to a building.

Rather than waste the electricity and incur the additional costs for cooling, Google has power supplies specially made that are 90 percent efficient. "It's not hard to do. That's why to me it's personally offensive [that standard power supplies aren't as efficient]," Holzle said.

While he admits that ordering specially made power supplies is more expensive than buying standard products, Google still saves money ultimately by conserving energy and cooling.

Google has data centres scattered around the globe but is usually reluctant to divulge details of the hardware and software running in the centres. Holzle spoke to journalists during his visit to Dublin for the final day of the European Code Jam, a contest for programmers sponsored by Google in an effort to identify talented potential workers.