Google Green

Our data centers

A closer look

Designing efficient data centers

When you use Google products, the servers hosted in our data centers do the work for you—around the clock and around the world. Our data centers use 50% less energy than the typical data center and are among the most efficient in the world. We’ve designed them to best use the natural environment and conditions. This means we use outside air in a cold climate or reuse water from a nearby water source to stay efficient even in hot, humid summers. We’ve worked hard to minimize the environmental impact of our data centers so that when you use our products, you’re being better to the environment.

We're proud of the firsts that our data centers have achieved:

We identify best practices and share them

We’ve continued to improve since we first disclosed our efficiency data in 2008. We’ve outlined our data center best practices below. And we'll continue to share what we’ve learned to help data centers of any size run more efficiently.

Google shuttle

1. Measure PUE

We can only improve upon what we measure, so we measure our data center efficiency using an industry-wide ratio called Power Usage Effectiveness (PUE). PUE compares the amount of non-computing “overhead” energy (like cooling and power distribution) to the amount of energy used to power our actual machines.

Typical data centers operate at about 70% overhead. This means that for every unit of energy that powers the servers, another 0.7 units are used for cooling and lighting the building. Our data centers have reduced this overhead to just 12%, making our PUE 1.12. There are different methods to measure PUE, and we believe in a comprehensive approach. Learn more here.

2. Manage airflow

Keeping the internal temperature of a data center at the right level is critical to healthy computer and server function. Good air flow is therefore fundamental to efficient data center operation. First we use thermal modeling to locate “hot spots” and better understand the air flow in our data centers. Then we use simple, cost-effective tactics (like sealing sheet metal and hanging plastic curtains) to prevent hot air from mixing with the cold.

3. Adjust the thermostat

One of the simplest ways to save energy in a data center is to raise the temperature. It’s a myth that data centers need to be kept chilly in order for the equipment to run properly. By turning the thermostat up to 80 degrees and encouraging our data center employees to wear shorts, we eliminate the need for energy-intensive air conditioning on the server floor.

4. Use free cooling

"Free cooling" is removing heat from a data center without using a large air-conditioner, or chiller. This is done by using the natural environment to cool the equipment, such as cold outside air, water evaporation or thermal reservoirs. We take advantage of local conditions and use free cooling at all of our data centers. Avoiding the need for mechanical chillers is the largest opportunity for energy and cost savings.

5. Optimize power distribution

We’ve found that up to a third of the total energy consumed by a typical server is wasted before any energy reaches the computing components. To combat this, we use high-efficiency power supplies, minimize the number of times we convert power from one type of electrical current to another and keep power supplies as close to the load as possible. Our servers lose only 10-15% of the electricity they consume during power conversion steps—around half of what is lost in a typical server.

With these and other design choices, we’ve saved a billion dollars to date and are eager to share our findings. Check out this case study in which we explain how others can reduce costs and environmental impacts through efficiency.

Explore Google data centers further at our data center site.