SWINDON, United Kingdom — Capgemini next month will open what it calls the "world's greenest" data center in Swindon, and appropriately enough will be hosting the U.K.'s Environment Agency as its first tenant.

The 33,000-square-foot facility, nicknamed "Merlin," boasts a Power Usage Effectiveness ratio of 1.08 (according to eWeek), meaning it uses much less than half as much energy per square foot as the industry average PUE of about 2.5.

The compute center achieved its energy efficiency through a number of methods. It will be using a combination of free outside-air cooling and energy-efficient evaporative cooling. According to a walkthrough of the facility by ZDNet:

The method used in the datacentre for cooling and recycling the air is a five-stage process. The air first passes through a filter, then a set of filter bags, a direct-expansion chilling system, an adiabatic pre-evaporative cooling system (pictured) and finally a series of fans. The direct-expansion chilling is not powered by default, but the electricity kicks in if the ambient air temperature is registered as too high. Adiabatic cooling works by drawing the air through a filter, which is cooled by water. This helps to dissipate the heat and prevent evaporation.

Green data centers are becoming big business for the private sector and public agencies alike. In recent weeks, companies ranging from Facebook to Hewlett Packard to Microsoft have unveiled new plans for internal and customer-facing green data centers. And in June, President Obama signed an executive order requiring data center consolidation for all federal facilities, with an expected $3 billion in savings when the project is completed.