All data centers want to be more energy efficient but finding practical and economical ways to improve energy efficiency can be challenging. But, it is made even harder if a data center does not have a good grasp on their PUE. PUE, or power usage effectiveness, is the data center industry standard for measuring a data center’s energy consumption. Data centers have long been one of the largest energy consumers in the world so knowing your data center’s PUE and trying to improve energy efficiency is incredibly important. After all, the world needs data center to operate so a large degree of energy usage is understandable – but ideally a data center is not being wasteful with energy and is doing everything possible to maximize energy efficiency. Bloomberg offers a useful description of PUE and how it should be calculated, “PUE is a measure of a data center’s energy efficiency — the ratio of total energy used divided by energy consumed specifically for information technology activities. The theoretical ideal PUE is 1, where 100% of electricity consumption goes toward useful computation. All the other stuff — power transformers, uninterruptible power supplies, lighting and especially cooling — uses power but doesn’t compute, and as a result raises a data center’s PUE…A recent Uptime Institute survey of 1,600 data center owners and operators found that 2019’s average PUE is 1.67, and that “improvements in data center facility energy efficiency have flattened out and even deteriorated slightly in the past two years.” That PUE means that 60% of data center electricity consumption is going to IT, and the rest to cooling, lighting and so on.”
Assessing PUE & Improving Your DCIM
Most data centers that assess their PUE find that their data center could improve their energy efficiency. Improving PUE is not a simple undertaking, though, because it requires financial investment and organizational improvements to infrastructure and DCIM. And, it is vital that you not only focus on your current needs but look towards an evolving and future-proof DCIM. For example, rack density is something that can rapidly increase to meet scaling demands. This not only uses more energy to power equipment but for additional cooling as well. Without an effective DCIM that includes consistent monitoring of rack density, it is easy to lose track of increases that may warrant a reorganization of racks fo improved efficiency. Also, if not consistently monitored and maintained, your data center may be using outdated equipment that actually consumes more energy than it should and more than the cost of replacing it.
Optimize Data Center Physical Layout to Improve Your PUE
The physical layout of your data center may have been designed long ago, and a lot of different equipment has probably come and gone since then. With changes in rack density and cooling equipment, your old data center layout may no longer serve your current needs and may even be making your data center operate inefficiently. For example, is your data center layout optimized to maximize cooling efficiency? If not, you may be wasting energy on cooling that could be saved! There are various techniques that can be used to cool your infrastructure and some are better designed for certain scenarios than others.
A Focused to Improving Data Center PUE
According to the National Renewable Energy Laboratory (NREL), there are some aspects of a data center that are essential when calculating PUE and determining areas for improvement, “Studies show a wide range of PUE values for data centers, but the overall average tends to be around 1.8. Data centers focusing on efficiency typically achieve PUE values of 1.2 or less. PUE is the ratio of the total amount of power used by a computer data center facility to the power delivered to computing equipment.”
The National Renewable Energy Laboratory (NREL) also shares areas of your data center on which you should stay focused:
Data center operators calculate instantaneous PUE using the following components:
- Lights and utility plugs that are associated with the data center and dedicated mechanical room. The crank-case heater for the emergency standby generator is also captured as light and plug load.
- Cooling, which captures the power used by fans and pipe trace heaters associated with outdoor cooling equipment. The dedicated tower filter pump power is also captured as cooling load.
- Pumps that move water in the data center Energy Recover Water loop and the Tower Water loops, and also capture power used by the boost pumps that circulate water through the fan walls.
- Heating, ventilation, and air conditioning (HVAC), which captures fan walls, fan coils that support the data center electrical rooms, and the make-up air unit.
- IT equipment, which captures power used by the IT equipment on the data center floor.
The Many Advantages of Improving Data Center PUE
Not only is it economically beneficial to improve energy efficiency, it helps data centers meet governmental regulations and requirements. Additionally, many colocation partners today want to work with data centers that are committed to sustainable energy usage strategies. When determining what changes to make to your data center in an effort to improve your PUE, do not lose sight of the value of choosing renewable energy sources such as wind, solar, hydropower, or geothermal energy. Though it may seem like a large financial investment now, it will save you a lot in the long run, and may even attract more customers to your data center. Data centers will always use a lot of energy but the way that energy is sourced and whether or not it is used efficiently are what is most important. Fortunately, through a well-designed DCIM, consistent maintenance and monitoring, and making various improvements to your data center, you can improve your PUE.