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Sensing a turn-on: tracking people to save energy

Some flat screens with environmental images on them

Unfortunately, most of the things people can do to save energy come at some kind of cost in enjoyment. Flying less means we get to take fewer exotic holidays to distant destinations. It uses less energy to turn a computer off rather than leave it on standby, but then it takes longer to start up when you want to use it again.

A pair of computer scientists at Cambridge, Robert Harle and Andy Hopper, have cited that second example as the most common reason people leave their computers on all the time. So they’re trying to get round this problem by proposing an energy-saving system for offices that watches to see where its users go. If they’re near their computer it stays on, but when they get further away it goes to sleep. It even leaves enough time to wake up when you’re approaching, so you don’t notice a delay when you sit down to work again.

Less light, more bright ideas

Computers aren’t the biggest users of electricity in an office though – lighting is. So they’re also proposing a similar system for lighting, where if anyone looks like they’re about to go into a room or down a corridor, the lights come on. Again, it’s timed so the lights will already be on by the time the user gets there. The brains of the operation is a computer system that tracks each person individually, to within 3cm of where they are at any time. That technology exists already, and Harle and Hopper used real data from a building with the tracking system installed to see how well their idea would work.

It’s another example of computer science being used to help save the planet, but at Cambridge they’ve taken that idea a step further by getting together a group of researchers who all want to help. The group is called Computing For the Future of the Planet, and along with helping us keep our energy use down, they’re looking into predicting climate change, sensing the environment and coming up with digital replacements for physical activities. Soon they could be bringing us more ways to help the environment without even noticing.