Importance of PUE on Data Center Costs
Efficiency measurements such as Power Usage Effectiveness – PUE and Water Usage Effectiveness – WUE assist data center owners and operators. By assessing the entire operations it is easier to identify the areas to improve. This metric is not only beneficial for identifying a data centers environmental impact and carbon footprint, but also from a business operation perspective, it can help identify cost saving measures.
PUE is a scale of one to three, with one being the highest possible score. If the PUE was 1, it meant that the data center’s entire power supply was used to power only the IT equipment. PUE has fallen from 1.8 in 2011 to 1.53 in 2018, according to a recent survey done by Uptime Institute of 900 data centers and service providers. While this is encouraging, the study also revealed that outages and the severity of outages have grown in the past year. Consequently, the data center sector still has work to do in terms of improving PUE and outage rates.
Data center operation budgets can be destroyed by high power costs. In a co-location facility it is also critical to know how a data center bills clients for their power consumption. Most data center providers bill on a per-customer basis. Customer equipment power usage and shared overhead costs for the entire data center are included in the charges. Operating numerous utility feeds, multiple generators, and multiple UPS systems are examples of shared overhead.
Below diagram illustrates the percentage of data centers operating at specific PUE. As per uptime institute, the majority of data centers (47%) operate a PUE of 1.2-1.5. 38% are in the 1.5-2.0 range. This 38% of data centers could likely do some simple improvements to their data center, such as aisle containment and turning up the thermostat. This would result in lower PUE and cost savings. You can use our free online PUE calculator to see how much you can save through improving your energy efficiency.
How Can Data Centers Lower Their PUE?
Additionally, hot or cold aisle containment is advantageous. This strategy prevents the cold air from mixing with the hot air exhausted from IT equipment. This makes cooling more efficient, thus saving energy spent on cooling, which improves your PUE. Another advantage is that you can increase server density for the same volume of cooling, which can further improve PUE numbers by increasing IT load for the same, or less cooling load.
Are There Drawbacks in Measuring?
PUE is an excellent tool for the data center’s facilities department. It enables facility engineers to assess the impact of infrastructure modifications. This includes:
- Boosting the temperature
- Upgrading to a more efficient UPS
When we break down PUE into its constituents, it becomes clearer:
So, if our PUE has gone up, does this mean the data center is now less energy efficient? No, the data center is now more energy efficient. We are accomplishing the same work while using less energy at less cost.
If we don’t know how to utilize PUE to assess the effects of changes in the data center, it’s a useless benchmark.
Should we avoid virtualization because we know it would certainly increase the PUE? Absolutely not! When looking at our PUE across time, it’s crucial to notice when the virtualization occurred. We must track any changes in the infrastructure or IT load in addition to PUE so that we can link the changes to the PUE value.
What Else Should I Be Measuring?
AKCP Online PUE Calculator
Not only do you save operational overhead, but you lower the carbon footprint of the data center, which can open the possibility of government rebates and grants from green energy initiatives.
But how do you go about making these savings and implementing the changes in your data center that are required? AKCP has a wide range of sensors for your data center including cabinet thermal maps and differential air pressure sensors. These sensors allow you to make changes in your data center and with AKCPro Server see in real-time the effect it has on your PUE. You can ensure that your data center is running at optimal condition, without violating ASHRAE recommended rack inlet temperatures and ∆T as well as ∆P values.
Power Monitoring Sensor
The AKCP Power Monitor Sensor gives vital information and allows you to remotely monitor power eliminating the need for manual power audits as well as providing immediate alerts to potential problems. The AKCP Power Monitor Sensor is specifically designed to be used with AKCP’s sensorProbe+ and securityProbe base units. It has been integrated into the sensorProbe+ and securityProbe’s web interface with its own “Power Management” menu, allowing multiple three-phase and single-phase Power Monitor Sensors to be set up on a single sensorProbe+ or securityProbe depending on which readings are required. Please check the sensorProbe+ Modbus manual or the PMS manuals on our website for more detailed information on this. Power meter readings can also be used with the sensorProbe+ and AKCPro Server lives PUE calculations that analyze the efficiency of power usage in your data center. Data collected over time using the Power Monitor sensor can also be viewed using the built-in graphing tool. Combining this durable Power Monitor Sensor with the sensorProbe+ and securityProbe creates an IP-enabled power monitoring capable of monitoring:
- Phase Line Voltages
- Power Factor
- Active Energy
- Active Power
By employing the complete AKCP ecosystem of products, cabinet thermal maps, AKCPro Server, and power monitoring sensor work together to give a complete analysis and assistance in cutting your power costs and improving your PUE.