Top 10 greenest data centres
10 | 10. CitiGroup, Germany
Citigroup's data centre makes the list after enormous progress. Its giant data centre in Frankfurt started at 2.8 PUE and has been brought down by nearly half to 1.5, and the company is still on a mission to get it to 1.0. Awarded with a platinum rating from LEED in 2009, this building is covered in vegetation. Climbing greenery covers each wall of the 230,000 sq-ft building, which also features a roof garden. The plants absorb the heat to lower energy use and purify the air both in and around the buildings.
9 | 9. Green Mountain, Norway
The fjords aren't just natural works of art, they're also excellent sources for hydroelectricity. The aptly named Green Mountain data centre in the northern city of Stavanger sources water directly from the fjord, and uses gravity to pump it in. Therefore, the centre uses no energy in order to bring in the water that cools its servers. Since the water is a cool 46° Fahrenheit at any time of year, Green Mountain has a PUE of just 1.2.
8 | =7. Titan, USA
In Washington State, you'll find Titan Data Centre. This facility used to be a missile base for the Air Force before it was taken over for use as a server farm. Washington State has been one of the forerunners when it comes to green movement, so it's no surprise that this centre clocks in at a PUE of 1.18. The centre uses evaporative cooling, which essentially cools the machines as the water turns into a gas. Due to the desert heat of the location, the rate of evaporation is high, thus speeding up the cooling process.
7 | =7. Datadock, France
Datadock is located in Strasbourg, France, and uses water wells that were custom-built specifically for the servers. Using plentiful groundwater sources at a temperature of just under 54°, the centre manages to hit a PUE of 1.18. The water not only extracts the heat from the servers, but the whole system is designed to ensure zero pollution and zero waste. All leftover water can be reused again to cool off the servers.
6 | =5. Generation 4, USA
Microsoft wasn't always sporting the best numbers with its data centres, but the company also had a lot of opportunities and time to learn from its failures. By using ITPACs, or integrated server modules, the Generation 4 data centre runs more efficiently and requires less energy. After plenty of trial and error, Microsoft chose to move into a cooler climate to take advantage of the already chilly air. In the town of Quincy, WA, you'll find the Generation 4 data centre that sports a lowest PUE of 1.12, while its average is 1.16.
5 | =5. Wynyard, England.
The town of Stockton in Northeast England has proved to be one of the very best places for Hewlett Packard to practise its brand of green initiatives. Improving power usage from 1.2 to 1.16 in the past several years, it uses the already cold air that migrates from the North Sea to bring cooling costs down by up to 40%. For a company the size of HP, it is committed to improving energy processes as much for profits as it is for the environment.
4 | 4. EcoDataCenter, Sweden
This company has partnered with Schneider Electric to use nearby wind and solar power to keep its facilities cool. Aside from an impressive PUE of 1.15, the centre actually takes any extra heat generated from the servers and pushes it back into homes and businesses to be used. All this takes place in Falun, which is a famous mining town in the centre of the country.
3 | 3. Wyoming Data Centre, USA
Cheyenne has one of the best climates for passive cooling. This technique uses outside air that is filtered through an evaporative cooler to keep servers running at their optimum levels. Green House Data is a cloud hosting company with seven different locations, yet its Wyoming operation is most efficient at an average of 1.14 PUE. The dry air found in the state reduces the need for air conditioners and server fans.
2 | 2. Apple, USA
In North Carolina, Apple has made a point of starting to practise smarter habits with its power. While it won't publish its PUE, this centre is reported to tie with Facebook's Sweden centre at 1.1. It achieves this with the help of biogas, which is the renewable fuel source formed when organic material, for example food waste, starts to break down. With so many landfills nearby, the centre has plenty of energy sources. Apple is also using two 100-acre solar farms, which means the centre uses the most solar power of any data centre in the world.
1 | 1. Facebook, Sweden
On the northern coast of Sweden, you'll find the city of Luleå, home to one of Facebook’s many data centres. To balance out the company’s sizeable carbon footprint, Facebook has made a point of improving all data centres. Its Swedish facility has a PEU of just 1.1. Since northern Sweden is already fairly chilly all year round, Facebook uses the already cold air and treats it with water vapour. With the proper humidity, it can not only cool down the energetic servers, but it can also heat up the normal offices. The hydroelectric power at Facebook’s Sweden centre is so efficient that the company has been able to save costs on its on-site backup power too.