Data Center Water Use: A Broader Conversation

IO Phoenix Colocation Data Center Chilled Water Pipes

IO Group Leader of Sustainability Patrick Flynn responds to questions and comments surrounding the Wall Street Journal article “Data Centers and Hidden Water Use.” He explains why we need a broader conversation around water efficiency, and how IO is reducing water use by reducing energy use.

The Wall Street Journal ran an article yesterday titled “Data Centers and Hidden Water Use.” I’m quoted in it: “It’s not like we’ve ignored water. It just turns out that the lowest hanging fruit is investing in energy efficiency.” The issue of sustainability is a really important one – important to society, important to IO, and important to me personally – so I want to elaborate on my very brief quote in the Wall Street Journal, and also respond to some of the questions and comments that have come out since the article was published.

A broader conversation about data center water use

We have to set our discussion in the context of the role of the data center in our lives. One comment on Twitter suggested: “We need to take down those datacenters! Let’s get on [Facebook] and organize a campaign!” Oh, the irony (without the data center there would be no Facebook – and no tweet). Of course, we need data centers for much more than Facebook and Twitter, Netflix and Spotify, Amazon and eBay…I could go on. Data centers help radiologists and oncologists diagnose cancer (Iron Medical). They help the world’s first food bank stave off hunger (St. Mary’s Food Bank). They manage traffic lights, and run power plants, facilitate the financial markets, and keep airplanes in the sky. The data center is an inextricable part of our lives.

We need a broader dialogue around water efficiency. Let’s all agree that water efficiency – and energy efficiency, and reducing carbon emissions – is critical. We need to work to make data centers more water efficient. We also need to work to make power plants more water efficient, and agriculture, and the production of basic consumables like coffee. The thing is, some approaches are more efficient than others, and some ways we might look to minimize water use might actually backfire. (You don’t cut air conditioning costs by turning off the AC and leaving the refrigerator door open.)

The data center itself has actually been instrumental in improving efficiency in all those areas. Here are just a few examples of how society has been able to reduce water usage thanks to the data center:

The digitization of print materials has eliminated a lot of water use in an industry that uses trillions of gallons of water annually

If you read the Wall Street Journal article, chances are you read it online – meaning, you read it out of a data center somewhere. You probably receive and pay your bills online now too, thanks to, you guessed it, the data center where e-bills and payments are generated, stored, and processed. The digitization of documents that used to be printed – also known as dematerialization – has eliminated a lot of water use (consider that it takes 2.6 gallons of water to make just one sheet of paper).

Technological advances enable a 15% reduction in agricultural water use (which is 80% of all water use in my home state of CA)

70 percent of all the water used globally (80 percent of water used in CA) – is used by agriculture. (A critical use, no doubt.) Researchers at the University of Georgia have invented a GPS-based technology that allows farmers to more accurately target irrigation needs, reducing water consumption by an average of 15 percent (a huge amount of water considering how much agriculture uses to begin with). That technology relies on data aggregated and processed in a data center.

The data center itself has enabled us to design a more water-efficient data center

One of the most powerful benefits of IO’s modular data center technology is its capacity to help us learn how to run a data center most efficiently. (IO’s data center modules are outfitted with sensors that have to date generated 75+ billion rows of data center operations data.)

Analysis of that data has enabled us at IO to reduce water usage in three important ways:

1. Energy efficiency in the modular data center translates to millions of gallons of water saved

In an independent study conducted in 2012, Arizona Public Service compared the energy usage in IO’s traditional raised-floor data center in Phoenix to IO’s modular data center both housed within the same building. The study found that the modular data center reduced energy overhead needed for cooling infrastructure by up to 44 percent. The efficiency improvement translates into average annual savings of $200,000 per megawatt of average IT load, along with 1 million gallons of water saved and 620 metric tons of carbon dioxide eliminated. (Read more about the study here.)

2. Water and energy usage is directly correlated – to reduce water use in the data center, reduce energy use

The point I was getting at in the quote the Wall Street Journal printed is that water use and energy use are directly correlated – so the best way to reduce water usage in the data center is to reduce energy usage. That’s true in the processing and storage of data in a data center just as it’s true in the energy production at a power plant, or any other industrial process. In all those cases, we use water to create cooling. (Nuclear and coal-fired power plants, for example, consume about 500 gallons of water per megawatt hour of energy produced.)

Why is that? Using water for cooling in industrial processes works the same way that sweating works to cool our bodies – as the moisture evaporates, it takes the heat energy with it. In the data center, every bit of energy that comes in to the data center in the form of electricity needs to be cooled, and the most efficient way to do that is by evaporating water. Consider the parallel: When our bodies sweat and the air blows across our skin, the water evaporates and takes heat with it, so we cool down. Now imagine that our bodies didn’t sweat, so to cool ourselves we had to always be standing in front of a giant fan. That’s much less energy efficient.

To take the analogy a step farther: If our bodies aren’t as hot (because, say, they use energy more efficiently so don’t create as much heat) we don’t need as much sweat to cool down. The same concept applies in the data center: If the data center is more energy efficient – that is, uses less energy to run – then the data center doesn’t need as much water to cool. In fact, the relationship between energy use and water use is one-to-one, so if we cut energy use in half, for example, then we reduce our water use by half as well.

3. At the IO data center in Phoenix, customers can power their infrastructure with renewable energy – a huge water saver

Working with the local power utility, IO developed an innovative program that allows data center customers to buy renewable energy to power their data center. That translates into significant water savings because both solar power and wind power use significantly less water per megawatt of energy used than traditional power plants do. (While nuclear and coal-fired power plants consume about 500 gallons of water per megawatt hour of energy produced, photovoltaic solar and wind consume 1-2 gallons.) Renewable energy also has the important added benefits of zero carbon emissions.

(Read more about IO’s renewable energy pass-through program here.)

Bottom line

We need data centers. We need them for activities like forming protest groups on Facebook and watching Game of Thrones on Netflix. We also need them to ensure that food banks can continue to stave off hunger. And airlines can keep planes in the sky. And stock exchanges can keep money moving. And doctors can keep diagnosing life-threatening diseases.

And – we need data centers to be more water efficient (and more energy efficient), just like we need power generation and coffee production and agriculture to be more efficient. For our part, IO is already hard at work on exactly that.

Continue the dialogue

Join the conversation about water and energy efficiency in the data center. You can find us on Twitter @IODataCenters, Facebook, and LinkedIn.


Founded in 2007, IO provides the data center as a service to businesses and governments around the world. Trusted by some of the most demanding consumers of data center services, IO provides a framework for business sustainability: greater availability, lower latency, increased security, and improved efficiency. Learn more.