3 energy efficiency tips for data centers


3 energy efficiency tips for data centers

What lies beneath? Little-known secrets of data centers include underground cooling tunnels.

Server rooms and data centers use a lot of energy.  And it’s not just big data centers: The average commercial office building spends close to one quarter of its annual energy bill powering server rooms and closets.  Why are they such energy hogs?

The quick answer is that computer servers generate a tremendous amount of waste heat. Just one rack of blade servers, for example, can generate heat equivalent to four Weber gas barbecue grills, enough to cook nearly 300 burgers an hour. 

Fortunately there are a lot of things we can do to reduce data center energy consumption and cut our energy costs.  The most efficient data centers and server rooms, for example, use up to 80 percent less power, according to the Department of Energy. 

All well and good, but if you’re not an IT person, the data center can seem intimidating. Its climate is often uninviting, its inhabitants speak in strange tongues, and there are rumors of tunnels hidden beneath the floors.   (The rumors are true: It's called a “raised floor environment” and it helps distribute cold air from the AC units.)

Here’s why sustainability professionals should not be intimidated by the data center; instead, most IT organizations need their leadership to help make data center efficiency a priority.  The very real challenges associated with keeping our data safe, secure and available — and the fact that  energy efficiency is almost never a part of an IT professional’s training or job description — virtually guarantees that it stays the proverbial back burner. 

3 data center secrets revealed

Saving energy in server rooms or data centers is conceptually more straightforward than you might think.  There are basically three ways to make server rooms and data centers more energy-efficient:

1. Reduce the IT load.  Saving just one watt of power at the server level can result in nearly three watts of total savings in a data center, because less power is consumed supporting the electrical infrastructure and cooling hot equipment.

Strategies for reducing IT loads include server “virtualization” (which allows us to run more than one workload on a single server), consolidating lightly used servers and removing unused servers, smarter data storage, and buying more energy-efficient equipment, such as Energy Star qualified servers.

2. Manage airflow.  Airflow management is about delivering cold air from air conditioning units or fans to the fronts of servers as efficiently as possible, and removing hot exhaust air from the backs of servers as efficiently as possible.  Airflow management strategies involve orienting server racks and enclosing them to reduce the mixing of cold supply air and hot exhaust air, using variable speed fan drives in AC units, and deploying devices to direct cold air to where it’s needed the most.

3. Control temperatures and humidity levels more efficiently.  Because high temperatures and either damp or excessively dry conditions can harm sensitive data center equipment, temperatures and humidity levels must be managed.  However, today’s data center equipment can tolerate much wider temperature and humidity ranges than in the past. 

As a result, it’s often possible to save energy by doing less cooling and humidification and dehumidification.  Additionally, there are new, vastly more efficient ways to humidify air than the old standby of producing steam.  Another strategy for reducing cooling costs includes deploying “economizers,” which take advantage of lower outside temperatures whenever possible to avoid having to mechanically cool air.

4 steps to a more efficient data center

Learn just enough to be dangerous.  In as little as an hour you can become familiar with the most common ways to save energy in a server room or data center. Towards that end, Energy Star provides non-technical descriptions of energy-saving strategies. It also offers a free one-hour webinar for general, non-technical audiences.

Schedule a data center walk-thru to look for potential savings. Then discuss what you find with an IT energy efficiency specialist: schedule a free conference call with a vendor-neutral advisor from Energy Star. Simply attend one of the Energy Star webinars to learn more.  

Estimate potential costs and savings. Once you’ve identified an energy saving opportunity, estimate what it could be worth to your organization. Energy Star can help with that, too, with information about costs and benefits.  And don’t forget to approach your local utility: Many utilities offer cash incentives to organizations that implement energy-saving measures in the data center. (Be sure to talk to your utility company representative before starting work — these incentives are not available if your project is underway.)

Build a coalition for change. Sometimes it really does take a village. Share the opportunities you identify with friends in finance, facilities, and EHS to build organization-wide support for a more energy efficient and cost effective data center. 

For more tips, nonprofit Second Nature, Energy Star and my firm, AlterAction, are offering a free webinar. We invite you to join us August 11 for Data Center Efficiency 101: What Sustainability Managers Should Know.