Technology has had both positive and negative impacts on the environment. Communications technology, such as video conferencing and messaging, can reduce the need for people to travel and the adoption of digital productivity tools can lower use of paper. However, technology is a significant consumer of energy, and materials used to create technology hardware often have a negative effect on the environment.
Data centres are buildings or complexes of buildings which hold networks of computer resources. The digital services that today we use such as Amazon, Google, Microsoft and Apple all operate large networks of data centres in a number of locations across the world. There is a large industry of other data centre providers with many businesses involved in the provision of data centres and related services.
These data centres use a large amount of energy. In 2019, data centres accounted for nearly 3% of global energy use and 2% of global greenhouse gas emissions. Both of these figures are set to rise unless action is taken in the design and use of data centres.
Large data centres require excessive amounts of energy. Worldwide this amounts to over a trillion kWh (kilowatt-hours). A large data centre will consume more energy than a medium sized town.
The impact of this is that energy generated from non-renewable sources creates carbon-emissions which impact on the environment through increased emissions of CO2.
In an attempt to reduce the carbon emissions resulting from energy production, some data centres use solar panels, geothermal and wind turbines. Some large companies now claim that their data centres are carbon neutral.
Data centres generate large amounts of heat from the processing equipment within them. In order to function correctly, this hear needs to be removed and the processing equipment cooled. Data centres can use a variety of methods to cool their systems.
Systems may make use of external climate to cool equipment. This involved taking air or water from outside the data centre and pumping this through the centre to remove hear.
The need to cool systems in data centres is partly responsible for their high-energy usage, so building them in naturally cooler climates (such as Norway or Iceland) is becoming more popular. Other green examples of cooling systems include using cold seawater or rainwater as coolants, or dissipating excess heat by using it to evaporate water.
Data centres use the physical layout of the data centre to improve the efficiency of cooling. Typically racks of computer systems will be arranged so that there are alternative aisles of hot and cold air. The fans in the tracks are arranged so that cold ait is pulled in from on side and hot air is pumped out at the other.
Liquid refrigeration systems make use of liquid coolants, cooling them and then pumping them through the data centre. These liquid coolants can be used to cool the air or can be pumped through special heat sinks attached to computer systems that draw the hear away from the components directly.
Other environmental impacts of data centres include: