Data centre

A data centre is a facility housing the servers, storage and network equipment that process and store data, together with the power supply, cooling and security systems that keep them running.

Place in the digital footprint

Data centres are the second largest contributor to the footprint of digital technology, behind users' devices and ahead of networks. Public debate frequently reverses this order.

Their impact is not only electrical. Cooling consumes water, construction consumes materials and land, and the equipment inside is replaced on short cycles, which makes manufacturing a significant share of the total.

Categories

Enterprise data centres

privately owned, generally with moderate utilisation rates and average efficiency

Hyperscale facilities

designed for economies of scale, with better energy efficiency per unit of computing but very large absolute consumption

Edge facilities

small, close to users, intended to reduce latency and network transport

Indicators, and their limits

PUE measures the ratio of total energy to IT energy. Water use effectiveness measures water per unit of IT energy. Carbon use effectiveness measures emissions.

None of them measures whether the computing being done is useful. A facility running under-used servers can post excellent indicators while wasting most of what it draws. Actual utilisation rates matter more than any efficiency ratio.

Heat recovery

The heat dissipated can be reused for district heating, swimming pools or greenhouses. Several such installations operate in northern Europe. Recovery requires proximity to a consumer and a design that anticipates it, which excludes most existing facilities.

See also

• Power Usage Effectiveness · Green IT · Carbon footprint · Digital sobriety · Manufacturing