important to us.

They are how we deliver all of our web services

to all of our users.

A data center can mean a variety of things.

It can mean a small closet filled with a couple of

machines all the way to very large warehouse scale

buildings that are optimized for power use and IT computing

and filled with thousands of servers.

At Google, we spend a lot of time innovating the way in

which we design and build these facilities to minimize

the amount of energy, and water, and other the resources

that these computing facilities use.

In terms of the results of all of the work that we've been

doing over many, many years, now we use half of the energy

of the typical data center.

To put things into perspective, the entire ICT

sector, that includes mobile phones, computers, monitors,

cell phone towers, represents roughly about 2% of global greenhouse

gas emissions.

Of that 2%, the data center portion is

responsible for about 15%.

There's design choices that you can make for energy

efficiency that improve the performance

of your data center.

And these things are just best practices.

And adhering well to best practices, that's how you can

actually make the most improvement in

terms of energy use.

The results of the these types of activities return

Google millions of dollars in energy savings.

So the results are significant.

We've invited several members of our data center team

to explain some of these best practices to all of you.

KEVIN DOLDER: The first step in managing the efficiency of

your data center is to make sure you have the

instrumentation in place to measure the PUE, or power

usage effectiveness.

PUE is the ratio of total facility energy to IT

equipment energy within your data center.

It's a measure of how effectively you deliver power

and cooling to the IT equipment.

In 2006, the typical PUE of an enterprise

data center was 2.0.

Which means that for every one watt of IT energy consumed, one watt of

overhead was consumed by the facility to deliver the power

and cooling.

ERIK TEETZEL: Reducing the overhead is

really what you want.

You want PUE to get to as close to 1.0 as possible.

KEVIN DOLDER: Over the last 12 months, our TTM PUE was 1.16.

We've continuously measured that and it's gone down nearly

every quarter since we began reporting it back in 2008.

Last quarter the lowest data center was 1.09.

Ideally, you should measure PUE as fast as you can, as often

as you can, every second or so.

And the more often you can measure it, the more

meaningful the results will be.

It's important to measure PUE over the course of a year --

annually or quarterly -- to get a meaningful result.

If you just take snapshots in time the information won't be

realistic and it won't really be an actual measure of how

well your data center is operating.

One way to make it easier to manage is to incorporate the

PUE measurements into your building management system.

We do this at all of our sites at Google.

Without having easy access to this data we wouldn't to be

able to operate our data centers as

efficiently as we do.

ERIK TEETZEL: Once you have the ability to measure and

manage your PUE, the first step in terms of reducing your

data center energy load is to focus on the

management of the air flow.

The most important thing here is to eliminate the mixing of

the hot and the cold air.

And there's no one right way to do this.

Containment can be achieved through many different

approaches.

One thing we found very useful at Google is CFD analysis to

see where are your hot spots and how is your air flow going

actually be directed in your data center?

By doing so, you can actually model the way in which air

flow will go and it helps you make very simple design

choices to improve the air flow in your data center.

For example, in one of our computing and networking

rooms, we call them CNRs, we actually did some thermal

modeling to see exactly what air flow was doing.

Through that modeling we realized that the intake to

our CRACs was too low.

And that by simply piecing together some sheet metal we

could create extensions that would dramatically increase

the air flow quality into the CRACs.

We also did a bunch of other retrofits.

KEN WONG: Here in this corporate data center at

Google, we've implemented meat locker curtains that are very

inexpensive and easy to install.

These are hung from the overhead structure and they

separate the cold aisle, which is actually hot, and the hot

aisle, which is actually hotter.

We are set now to enter to hot aisle containment door.

And we incorporated these simple, inexpensive, sheet metal doors

to separate very tightly the cold aisle from the hot aisle.

Now over here, we've got the hot air from the racks

coming up, going over head, up through the return

air plenum

back to the CRAC units to give you a nice high temperature

differential across your CRAC units.

A very important step is to seal the rack space where you

don't quite have all of your equipment populated.

And it's very easy to do with these blanking panels.

It's almost like weatherizing your house to make sure that

you've got a nice, tight environment.

ERIK TEETZEL: All totalled, we spent about $25,000 in parts.

And those $25,000 saved us over $65,000 in

energy costs yearly.

Once you manage your air flow properly, the next step in

data center efficiency is to increase the temperature of

your cold aisle.

It's long been believed by many data center operators

that the data center has to be cold to keep all the equipment

at a temperature that it will run safely at.

And in fact, that's just false.

So if you look at recommended guidelines from ASHRAE, they

recommend you running all the way up to 80 degrees

Fahrenheit.

And at Google, that's exactly what we do.

We've got a small corporate data center here.

It's about 200 kilowatts of load.

Simply raising the temperature from 72 degrees to 80 degrees

saves us thousands of dollars in energy costs

every single year.

What's nice about that is it also allows our employees to

come to work in shorts.

Whenever possible, we recommend people to free cool.

Free cooling means utilizing ambient temperatures outside

of your data center to be able to provide cooling without

operating very heavy energy consuming

equipment like chillers.

CHRIS MALONE: We use free cooling at

all of our data centers.

And you can see this in our publicly recorded PUE data

where the PUE values go up in the summertime and down in the

wintertime.

And this is just a reality of running our operations

with free cooling.

And it yields tremendous efficiency gains.

In Europe, we have two data centers that have no chillers

whatsoever.

We're able to take advantage of the local constraints and

conditions.

In Belgium, we use evaporative towers without any chillers

given the ambient conditions.

In Finland, we use sea water cooling.

Sea water from the Bay of Finland cools the servers.

And then we temper the water returning to the Bay of

Finland so there's no temperature gradience

returning to the bay.

Evaporative cooling uses water on site, but what we found

through our studies is that by the use of evaporative cooling

in a very efficient fashion, we save water on the whole.

So for every gallon of water that we use in the evaporative

cooling plants, we eliminate the use of two gallons of

water on the energy production side.

This translates into hundreds of millions of gallons per

year in water savings.

There's no one right way to deliver free cooling.

The important point is that you should examine these

opportunities and take advantage of them to eliminate

or reduce substantially the mechanical cooling.

TRACY VAN DYK: In the data center, you pull power in from

the electrical grid and you convert it down to the

voltages that are needed for all the

components in the data center.

And there's a lot conversion stages in there.

By minimizing those conversion stages, you can save

money and save energy.

Also by making each conversion stage more efficient you can

save energy, as well.

Traditionally, one of the biggest losses is UPS,

Uninterruptible Power Supply.

Typically, there's a giant room of batteries.

The batteries are DC voltage.

And the power coming in to charge those batteries is AC.

And so you need to convert from AC down to DC with a

rectifier in order to charge the batteries.

And then when the batteries are needed in a power event,

you need to convert that back to AC with an inverter.

And then the AC needs to be converted back down to DC for

all the components in the data center.

So you've got three conversion stages in there

that are not necessary.

What Google has done is put a battery on board the tray.

So you're eliminating those three conversion steps.

You just have DC right into the server components.

In a typical server configuration, you have a

server with an AC/DC power supply attached to it.

By making sure that AC/DC power supply is efficient, you

can save a lot of energy.

Things like Energy Star labels will point you to power

supplies that are 90% plus efficient.

Google is able to save over $30 dollars per year per

server by implementing all of these features.

ERIK TEETZEL: There really are very simple, effective

approaches that all of us can implement to reduce the data

center energy use.

And most of them are cost effective within

12 months of operation.

So a lot of efficiency best practices should be adopted by

just about everyone.

They're applicable to small data centers

or large data centers.

It's simply following the five steps that we go through here

to make sure that you're able to reduce your energy use.

1. Measure PUE 2. Manage Airflow 3. Adjust Thermostat 4. Utilize Free Cooling 5. Optimize Power Distribution