Data center energy consumption today is so enormous, that if all the data center sites around the world were a country, they would rank as the 5th largest energy consumer globally. Emerging technologies such as big data, IoT, and AI place a high demand on IT resource capacity, and data center professionals are tasked with keeping up with this demand while reducing space, power, and cooling resources to improve efficiency and save money.
Still, green data centers have innovated ways to do more with less energy. Despite the incredible growth in data center demand over the past decade, total data center energy consumption only increased by 6%.
Here are some of the best practices that cutting-edge data center managers rely on to optimize their data center energy consumption:
1. Introduce instrumentation and sensors to meter and monitor the environment.
The first step to increasing data center energy efficiency is to collect data on how much power you are using and what is happening in your environment. Metered power infrastructure such as intelligent rack PDUs, bus drops and busway end feeds, remote power panels, floor PDUs, UPSs provide critical data and insights into the utilization of your power distribution infrastructure. Environment sensors such as temperature, humidity, and airflow help you determine if equipment is operating within recommended ranges.
Deploy meters and sensors, and then unlock their full potential with Data Center Infrastructure Management (DCIM) software. DCIM software collects and stores the live readings and transforms them into actionable insights in the form of business intelligence dashboard charts and reports, visual analytics, ASHRAE cooling charts, and thermal time-lapse videos.
Trend data and KPIs, such as Power Usage Effectiveness (PUE), over long periods to see which direction you’re heading in and to understand the impact of efficiency initiatives. Set thresholds on power and environmental data to be the first to know when conditions in the data center are outside of your normal operating range so you can remediate the issue and maintain high levels of efficiency.
2. Increase temperature set points and follow ASHRAE guidelines for rack inlet temperatures.
Modern IT equipment can run safely in warmer environments, yet many data center managers overcool their equipment which wastes energy and money. With temperature sensors and DCIM software, it’s easy to safely raise temperatures to instantly improve efficiency while ensuring that the equipment is safe so you won’t experience downtime.
To achieve this, first make sure your temperature sensors are placed properly. ASHRAE’s thermal guidelines recommend placing no fewer than six sensors in each rack, mounted at the top, middle, and bottom of both the front and back of the rack. Then, with DCIM software you can set appropriate rack inlet thresholds to be alerted of over-temperature conditions. A modern DCIM tool will have built-in ASHRAE cooling charts so you can determine if you are compliant with recommended ranges. Slowly raise your CRAH/CRAC set points and check your cooling charts again to ensure equipment remains within ASHRAE guidelines. In some cases, you can even turn off CRAH/CRACs completely. Finally, periodically check your temperature trends and thermal heat map and make any necessary adjustments.
3. Introduce hot/cold aisle containment.
Data center containment is the separation of cold supply air from the hot exhaust air of II equipment. Containment enables a uniform, stable supply temperature to the intake of IT equipment and warmer, drier return air to cooling infrastructure. Containment has proven to reduce energy consumption, increase cooling capacity, unlock more power capacity for IT equipment, and extend the life of equipment.
You should consider either hot aisle containment in which warm exhaust air from IT equipment is enclosed and returned to cooling equipment or cold aisle containment in which the aisle where cold supply air is delivered is enclosed and the rest of the data center becomes a hot air return plenum.
Modern data center managers go a step further and use DCIM software and temperature sensors to monitor and report on containment strategies. DCIM software enables you to collect real-time environment data and automatically plot it against ASHRAE or customized thermal envelopes to see hot spots at a glance, know when to increase or decrease temperature set points, and simplify the management of airside economization.
4. Consider data center consolidation and virtualization.
To decrease the number of physical assets and the associated space, power, and cooling resources they consume, today’s data center managers are increasingly looking to consolidate hardware and turn their focus to virtual assets.
Consolidating equipment, racks, or even entire sites enables you to increase efficiency by migrating workloads to fewer physical locations or the cloud. With less equipment and sites to power and cool, energy consumption is dramatically reduced.
DCIM software is a must-have to maximize efficiency during a consolidation or virtualization project. DCIM helps you track the location and details of all your assets, know how much power they are using, identify ghost servers, and find stranded capacity to safely deploy more devices in fewer racks. It also provides performance metrics like CPU utilization/processor load, number of system processes, and memory usage, and other metrics like the number of hosts and virtual machines (VMs) per cluster, hosts per application and OS, and the number of physical versus virtual assets.
5. Minimize bypass airflow.
Since cooling can account for roughly half of total data center energy consumption, it is necessary to optimize airflow to improve efficiency. Bypass airflow, or airflow that does not pass through IT equipment before returning to a cooling unit, must be kept to a minimum. Blanking panels are a low-cost solution that improves airflow, decreases server inlet temperatures, and increases CRAC return air temperature. Panels alone can reduce energy costs by 1-2%. Be sure to plug overlooked holes such as open U spaces, spaces between rails and edges of cabinets, and under cabinets.
Raised floor grommets are useful in sealing new or existing cable penetrations in your raised floor. They allow maximum pressure to be maintained in the sub-floor plenum while still allowing cables to enter enclosures. High flow cabinet doors can also be used for roughly 20% improved airflow compared to standard doors.
And last, installing efficiency hoods on your CRAC units allows the units to receive warmer air by extending your unit up to the return plenum. Pulling the hottest air possible out of the data center causes the temperature to get cooler and to cool quicker, improving cooling capacity and efficiency. Hoods can lower the temperature of the cold aisle by 1-2 degrees and allow CRACs to cycle off more frequently, extending their lifespan.
6. Bill back customers for the energy they use.
Many organizations have green data center initiatives to drive energy-efficient behaviors from internal or external customers. However, ensuring compliance with those initiatives can be difficult, reducing their impact.
To encourage your customers to follow energy efficiency best practices and drive a culture of awareness and accountability, charge your customers for the energy their equipment consumes. DCIM software collects displays energy and cost data in bill back reports which can be delivered by customer, data center, or even rack. Understanding and allocating costs by customer, business unit, or application makes it easy to identify power hogs and eliminates human error so your charges are always accurate.
Bringing It All Together
Increasing data center energy efficiency provides many benefits such as a reduced carbon footprint and reduced operating expenses, but it continues to be a challenge for many data center managers. To effectively reduce energy consumption and save money, follow the steps that industry experts have proven to work. Deploy the right hardware and software in your data centers, follow best practices, and you will quickly and easily see improvements in your energy efficiency.