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What is PUE: Power Usage Effectiveness

5 Minute read
what is PUE

Data centers are used to power and support every business from small startups to the largest corporations. In fact, at any given time, data centers are using as much as 2% of the world’s electric supply. As our dependence on servers continues to grow, efficient data centers are going to continue to become more necessary too. So how can we ensure that our data centers are up to the task? With a tool called Power Usage Effectiveness, or PUE.

Engineers take every opportunity to reduce the power consumption of their data centers and one method they use to measure their success is PUE. Here, we will discuss some basics of PUE, including what it is, what the standards are, how you can improve your own PUE, and why it all matters in the first place.

What is PUE and How is it Calculated?

In short, Power Usage Effectiveness relates the total amount of energy entering a data center to the portion of that energy being used by IT equipment.

Total energy includes all the electricity, as well as energy produced by alternative sources such as natural gas and water.

Energy consumed by IT equipment is the amount of energy used to manage, store, process, and route data within the center. Additionally, it is the energy used to operate networks and other devices such as monitors or workstations.

IT equipment can also take the form of:

  • Cooling
  • Heating
  • Ventilation
  • Power conversion & distribution
  • Lighting
  • And Utility plugs

As a relationship between the two, Power Usage Effectiveness can be visualized as the following equation:

What is PUE Used For?

The PUE relationship is helpful to data center engineers as it can be used to determine how efficient a data center is. It can also be used to measure how efficiency changes and develops over time. However, PUE cannot be used to compare data centers to other data centers.

What is a Standard PUE for Data Centers?

The PUE ratio can range anywhere from one to infinity, one being the most ideal. A PUE of one shows the analyzed data center is running with 100% efficiency, meaning all consumed energy is used only on IT equipment and none is wasted. While this would be the standard in an ideal world, the level of efficiency is impossible to achieve as of the writing of this article and likely will remain that way. However, some companies are getting very close to achieving this “PUE Perfection.”

Industry leaders such as Microsoft and Google are creating data centers which have PUE’s of 1.2 or better. To be that efficient takes a huge amount of planning, resources, and funding, so these numbers should not be taken as an example for more standard data centers. According to Uptime Institute research, U.S. data centers have an average PUE of around 2.5. Servers with a PUE of 3 or higher are also common.

When determining your own PUE, you should look to be somewhere within that range if you want to be operating at maximum efficiency without completely breaking the bank.

What Factors Impact PUE?


On average, roughly 43% of the energy used in data centers is allotted for cooling systems. However, if your data center was constructed in a cooler climate, it will take less energy to cool itself. In turn, your data center will be naturally more efficient with a better, or lower, PUE.

Reduced Load of IT Equipment

There are several methods to help lower the load of your IT equipment and reduce your data center’s consumption of power. Two easy solutions are to purchase energy efficient equipment and remove idle servers.

Improve the Cooling System

“Free cooling” systems are some of the best in the industry as they use local modular cooling. By directly sending cool airflow into areas where it is needed most, you can prioritize a more effective system.

For example, you may want to channel cool air towards the front of servers and remove hot airflow from the back. Different data center engineers will have different ideas on the best structures, so work with someone who you trust to get the job done correctly.

Why PUE Matters to Data Centers and Their Customers

As previously stated, PUE helps data center owners judge how well their facility is operating. It can also help them identify areas to improve. By being able to have a standard system of measurement for energy efficiency, data center operators can potentially lower costs as well.

Accordingly, PUE can also have an impact on customers. As owners begin to discover ways to reduce the cost of operating their data centers, those savings will be passed on to the customers as well.

FGC Construction: Experts in Power Usage Effectiveness

In the world of data centers especially, PUE is a critical evaluation tool. As our need for efficient energy use continues to compound, data centers with the lowest possible PUE’s are going to need to be the standard.

FGC Construction has extensive experience in data center construction for all sizes of facilities. Our team is focused on meeting your project requirements, budget, and desired outcome and we are ready to help you design the most efficient facility possible to save you time and money.

If you are ready to get started, call our team of professionals to assist in your next project or fill out our contact form. We look forward to helping you at every step of the way, from determining scope and budget, to executing the most difficult and important stages of your next project.

  • FGC Construction installed an entire megawatt of UPS and generator upgrade to our 3d Printing facility. This holds our power stable and provides unlimited runtime. Much appreciated!

    Lee M.COO - Boston, MA
  • FGC Construction delivered 2.5MW of high density data center in the middle of Silicon Valley. City planning to utility negotiations. Very impressed!

    Tim S.CFO - Silicon Valley, CA

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