Zerofootprint: Black is the new green: Sources for computer power consumption

We've got a heap of responses to "Black is the New Green," and they tend to fall into three themes. The first is to commend the idea of making computers more energy efficient through power-saving software. The second is to suggest that much of what we suggest is already possible for anyone who takes the time to configure their machine; in other words, the goal should be education, rather than software development. The third is to express incredulity at our numbers.

There's not much point responding to the first set of responses, except to say thanks. We appreciate it.As for the second, we agree: education can go a long way. But not far enough. The fact is that we need to be educated about a lot of things right now: about making our cities sustainable, about the environmental consequences of our driving, of our travel, of our consumer choices, of the food we eat, of our landscaping decisions, and so on. The power we waste on our computers is a small piece of the puzzle. That's not to say that it's not important. But we have to acknowledge that a lot of educators are vying for our attention, and it could be a while before people get around to changing the settings on their computers. Why not create a tool to make it easier for them?

A software solution has something else to recommend it: whatever we develop will have the ability to quantify the electricity savings, and aggregate those numbers centrally. We will be able to keep a running count of the "nega-watts" - that is, the power that doesn't get used. This is a powerful tool.

For one thing, just seeing the immense savings (in kilowatt-hours, in dollars, in CO2 emissions) will be a powerful educational tool. What gets measured, gets managed. In other words, the more you save, the more incentive you have to save more.

For another, if we can quantify rigorously enough, we'll be able to issue and sell carbon credits to create revenue to plough back into the project. In other words, the more power we save, the more we'll be able to save.

Neither of these tools is available if we just show people how to configure their machines.

Finally, a response to those who have concerns about our numbers. It's true that much of the math is based on speculation. It is meant first of all to show the sheer scale of the problem. We can't know how many of the world's 650 million computers are turned on but idling, or what their screensaver settings are, or even exactly how much power all the world's graphics cards draw. There are too many variables to get an exact number. But we do know the number is huge.

Still, though we did have to use some proxy values, the math is based on real numbers, which we have in some cases discounted to ensure that we're not overestimating.

First, here is a link to a simple calculator that will give a sense of the power requirements of a system of just about any combination of hardware, not including monitor. It is very easy to get to 200W, which is higher than the number we used.

The graphics card can make a huge difference, in some cases jacking the power usage up over 450W. Again, this is three times the number we used in our calculations.

The monitor also makes a difference, of course. Switching from CRT to LCD offers a savings of about 60%. That's a drop from 100W to 40W. Imagine what shutting it off altogether would save, and giving the CPU and graphics card a break when you're not using the machine.

We're talking about a lot of energy going to waste. That means squandered money for those paying the bills, and it means unnecessary greenhouse gas emissions from the plants that generate the power. The CO2 emissions will vary depending on the source of the power, of course. Computers wasting electricity from a nuclear plant won't warm the globe as much as machines wasting electricity from a coal-fired plantbut it still doesn't make sense to build expensive, risky nuclear plants to keep computers idling. And let's take into account that some computer-intensive companies draw more power than the local utility can provide, and are forced to install their own diesel generators, which raise the environmental cost quickly.

With more computers drawing more electricity (to say nothing of all the video games out there—a PS3 uses more than an order of magnitude more power than the first Playstation), the situation is only going to get worse. We can begin the process of turning all that around, we can do it in such a way that the project sustains itself, and in such a way that it helps educate people about energy and its environmental costs.

Let's not delay.

[Ron Dembo, Zerofootprint]

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