Google Watches Its Watts

Bill Weihl, director of energy strategy at Google (and an IEEE member), talks about energy-hogging computers, the sex appeal of servers, and the trouble with power plugs

7 min read

In June, Google and Intel announced a Climate Savers Computing Initiative to raise the energy efficiency of the world's computing equipment. The goal is to reduce the amount of global carbon dioxide emissions by 22 million metric tons per year by cutting the amount of energy consumed by computing equipment. According to the initiative's extrapolations, this figure is equivalent to the annual emissions of 11 million cars.

The launch came one month shy of the new Energy Star 4.0 standards in the United States, which go into effect on 20 July. The new specifications will raise the bar on which computers and related devices can earn the Energy Star label, which denotes the devices' superior efficiency. At the time it launched, 40 companies had signed on with the initiative, which sets deadlines by which companies are required to meet certain energy consumption targets.

IEEE Spectrum spoke with Google's Bill Weihl about the program and how participating organizations are planning to meet its goals.

IEEE Spectrum: What brought about the Climate Savers Computing Initiative?

Bill Weihl: We started talking to Intel about it a year ago, and over time we conceived of it as an industry consortium to try and drive higher efficiency for computers across the industry. Not just in high-tech industry, but all uses of computers. We've done a lot of work on our own here on energy efficiency, especially on our own servers. Our goal is to make that same efficiency available to everybody, whether it's servers, laptops, desktop workstations, and so on.

We launched in June with about 40 members who are committed to, in the case of manufacturers, producing high-efficiency systems and, in the case of everybody else, to purchasing high-efficiency systems and making extensive use of power management across their fleet of desktops and other computers. We think that any company that looks at the economics of it ought to conclude fairly quickly that the measures we're talking about will actually pay off in two to three years. For servers it's probably closer to 12 months. So there's little to no downside to commit to buying high-efficiency systems, and my hope is that over the next six months virtually every company signs up and commits to this.

IEEE Spectrum: What are the program's targets?

Weihl: The initiative starts in terms of efficiency targets with the new Energy Star 4.0 standards for computers, which require the power supply in a desktop to be at least 80 percent efficient.

To go beyond what Energy Star has done, we've set up a staged yearly improvement in energy efficiency. In the second year, we're then raising the bar on efficiency for the desktop power supply to 85 percent, and then to 88 percent, and then 90 or 91 percent in each subsequent year. So each year there will be a small and incremental improvement in efficiency, so that by the end of the fourth year of the initiative we'll be at 90 or 95 percent. And our intention is to set similar efficiency targets for the motherboard for later years of the program.

IEEE Spectrum: How efficient are computers now?

Weihl: For a typical desktop, the power supply is probably 65 to 70 percent efficient. Over the last 25 years, the computing industry has been driven by price and performance--whatever was cheapest and didn't cause the box to overheat. There's been some attention paid to energy efficiency--when things start to get too hot or when the fan noise starts to get too loud.

The technology is there today to do better. The new Energy Star standards limit the amount of power computers can use in sleep, standby, and idle modes. So when a computer is asleep or in standby mode, then it can consume a single-digit number of watts. When it's just idle, running, then it's about 65 watts, maximum.

IEEE Spectrum: What's been Google's experience with improving the efficiency of its own equipment so far?

Weihl: For at least four years we've been using power supplies in our servers that are over 90 percent efficient, and there are a number of companies building servers with power supplies today that are that efficient. When you want to pack them in tightly, it becomes an issue of not just energy consumption but also the amount of heat you produce. We also expect to introduce targets for motherboard efficiency, for dc-to-dc converters, and that over the next four years they'll get to the 90 to 92 percent range. This will be a huge benefit to people who run big server farms. Financial services, retail, many industries today are remarkably IT intensive.

In a typical industry data center, for every watt the server itself consumes, there's another 1 to 2 watts in cooling and other overhead in the data center, which means if you eliminate a watt from a server through efficiency, you're eliminating 2 to 3 watts from a facility. Our overhead is much, much less than that.

When you add together the components of a system, the net efficiency you typically get from wall current to actual components is about 50 percent. So you lose half the energy coming out of the wall before you get close to the computing components. And all that turns into heat, which you then have to get rid of. So in an air-conditioned environment, you have to spend more energy to remove that heat. We're losing about 20 percent in the power conversion. In a typical desktop it's more like 50 percent, and in a typical server it's probably 30 to 40 percent.

IEEE Spectrum: What are the price differences now between typical and high-efficiency equipment?

Weihl: For a desktop, we estimate it'll cost about $20 more to buy a desktop system that is Energy Star 4.0-compliant. That'll give you an energy savings of US $7 to $10 a year. So it'll take two to three years to pay back, which is about the lifespan of a system at a typical organization. For a server it's probably about $30 additional for the increased efficiency, and it can be paid off in about 12 months.

Many companies out there haven't specifically talked to their vendors very much about the energy efficiency of the servers they're buying. And in some cases we've heard them say they'd love to buy more efficient servers, but they just don't know where to get them. But they're out there. We've already told our vendors that in subsequent years we're going to raise the bar on how efficient we want our systems.

IEEE Spectrum: What are some of the hesitations you've heard from other companies?

Weihl: There's actually been remarkably little hesitation, which is very gratifying. I've had some people I've contacted say, ”I don't pay the electricity bill,” and ”I don't even know who the guy is who pays the electricity bill.” So those people have to meet, and the organization has to make it relatively easy to move what I think are small amounts of capital into the proper budget to authorize the efficiency upgrades. Moving small amounts of money from one part of an organization to another is hard for some places.

There are also challenges sometimes to using power management, depending on how a company's IT group handles software updates. It might not be okay for the client machines to go to sleep at night, because IT needs to be able to log in or do something. So there are challenges there. But I think everyone who's had a chance to take a look at it and think it through has said yes. And some of them just said they need a little more time to think about this to figure out internal processes.

IEEE Spectrum: What are some of the challenges in making servers more efficient?

Weihl: Servers tend to use more power than desktops. A desktop uses 100 or 150 watts, while a server might use 150 to 300 watts. And it certainly depends on the server. There are some that use more power than that. In addition, servers tend to run all the time. There's less opportunity to put them to sleep. There are some organizations that are maxed out at their existing data centers, not because of floor space but because of the amount of power they can deliver or the amount of cooling they can do. So if they can reduce the amount of power consumed by the servers by 10, 20, 30 percent, then they could put more servers in their facility and possibly get more work done and possibly grow their business faster because they don't have to build a whole new data center. So the potential economic benefit to many businesses in terms of higher efficiency is much, much greater than what you would get just in terms of consuming less energy.

But we also need people to do really simple things that don't involve new hardware changes, like using the power management settings built into their desktops. Put your machine to sleep or turn it off when it's not in use. Don't just use a screensaver, which is actually one of the most energy-intensive things you can do on your computer, because it's exercising the CPU, exercising the graphics card, and it's keeping your display on. I think most people wouldn't just leave lightbulbs burning all the time when no one's using them, but that's what we do with our computers, and it's kind of silly.

What we're doing with these systems today, it's a little bit like buying a hybrid car that can shut off at a stoplight, but we're somehow forcing the engine to stay on. We've got the capability to have it shut itself off when it's not doing anything, and we're not using it. I'm sure the tools that are there could be easier to use and so on and so on, but a lot of it is just lack of awareness.

IEEE Spectrum: How much do you think Google's energy consumption will decrease?

Weihl: For computers I would say at least 50 percent, and possibly 60 to 70 percent over, say, the next two years. People talk a lot about huge server farms consuming all this energy, and I think partly that's because for whatever reason, they're sexy. When you think Google, you think big server farms. But there are a lot more desktops and laptops in the world than there are servers. Yearly shipments of desktops are about 140 million. Yearly shipments of servers are about 10 million. Now, a server uses more energy, it's got a higher power draw, it's on more hours of the day, and so on, so maybe desktops overall consume only five times as much energy as servers. Okay. Saving 60 to 70 percent of the energy used by those several hundred million desktops today is actually a really big deal. It's distributed across people's homes, it's distributed around office buildings, it's not in central facilities. But in aggregate it's an enormous amount of energy.

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