Researchers at Imperial College London claimed in a report last year that up to 200L of water could be consumed per gigabyte of data downloaded.
They also said the figure could be as low as 1L of water per gigabyte, so there's plenty of speculation involved - the true figure is probably somewhere between the two. The fact is that IT consumes a huge amount of water. US Data Centres alone consumed 626 billion litres of water in 2014, and this figure is expected to rise to 660 billion litres in 2020. Compare that with only 150 billion litres of water drunk in the US each year for some perspective!
Think about how much data you use on a daily basis, and how much water that's using. Huge numbers are often splashed around to demonstrate how much technology has taken over our lives, but here's a couple to illustrate the point:
2.6 billion people are estimated to use email
205 billion emails were sent every day in 2015
Over 1 billion websites are online today, compared to 0 in 1990 (that's not a typo!)
Data Centres have been under scrutiny for energy usage for some years now, and understandably so - their carbon footprint is second only to the airline industry. However, water consumption has been largely ignored until recent months.
A 'hot aisle' at a Google data centre. The cooling fans on the servers blow air into hot aisles and then chilled water coils cool the air. Water is pumped to and from the cooling towers in the pipes shown on the left of the photo.
Water is pumped round for the cooling processes which are so important to the stability of servers in data centres. While some cooling is done by air, water has 50-1000 times the capacity to remove heat than air does, so is still largely favoured. However, much more water is used in the process of making the billions of kilowatt hours of electricity at power stations that are used in data centres. The electricity sector is responsible for 50% of water abstractions in England and Wales.
As pump engineers we spend a lot of time making pump systems more efficient, fitting variable speed drives to pumps to reduce the electricity used, and replacing old pumps with modern, efficient versions. Most facilities managers maintaining pump systems are aware of the cost savings that are available through reducing energy usage, and it's easy to focus on data centres with colossal water consumption, but question of how much water is being used should be brought into the decision-making process more. Could your pumps be consuming more water through the power cable than they are through the impeller?