Low-power computing promises to boost companies’ profits
October 24, 2010
The IMEC laboratory in Belgium is a surprising place. Nestled in the sleepy university town of Leuven, its low-key entrance gives little clue to the high-tech facility within.
The heart of the complex is a massive, dust-free ‘clean room’, staffed by carefully-wrapped technicians. Here, microchips are developed based on sophisticated and carefully guarded designs.
But unlike unlike consumer chips from Intel or AMD, IMEC’s microchips are not meant to be powerful – they are the exact opposite.
They have been tweaked to run on the tiniest amounts of power – so tiny, in fact, that they can run on energy harvested from small movements or temperature differences in the environment.
Daily attire
One of IMEC’s creations is a prototype headband that monitors a patient’s vital signs, and wirelessly transmits an SOS to medics if the patient suffers a heart attack or epileptic fit.
Although the prototype is still rather unsightly, it has an important advantage: instead of being powered by batteries, it gets all the energy it needs solely from the warmth of the patient’s forehead.
"Patients want to feel safe, and know that if they have a problem someone will come to help," says IMEC program director Bert Gyselinkcx.
"But they don’t want to come home every evening and start recharging their sensors",
"So there’s a need for devices that are ultra low-power, and which go beyond that and energise themselves even while they’re in use."
While the environment is full of free energy, it only exists at very low voltages.
For any type of computing device to harvest this energy, its microchip must be able to work with so-called ‘sub-threshold’ voltages – voltages at which a normal transistor would turn itself off.
‘Off’ is the new ‘On’
As Mr Gyselinkckx’s team expand the range of functions that can be achieved at sub-threshold voltages, they could revolutionise not only the market for niche headbands, but the entire world of computing.
"There is a tremendous drive today to reduce the power consumption of all kinds of electronics that we’re using – computers, cell phones, laptops", says Mr Gyselinckx.
"The techniques we’re using to make ultra low power devices for body sensors could also be used in these applications."
It is an attractive idea – laptops that power themselves from the heat of your lap. But Mr Gyselinckx admits this is still some way off.
In the nearer future, ultra low-power chips are more likely to reduce energy demand in less direct ways: movement sensors that switch a monitor on or off, or self-powering peripherals like keyboards and mice.
But is this such a big deal? How much electricity do normal computers actually use?
Night at the museum
Those who doubt the scale of the IT power drain should take note of an estimate by Jonathan Moffett, in charge of information technology at the Ashmolean Museum in Oxford.
The museum has 200 workstations – a minuscule number compared to big organisations – but Mr Moffett calculates that they contribute around $25,000 (£16,000) to the museum’s annual electricity bill.
Rather than wait for energy harvesting to become mainstream, he did some detective work. He discovered that around 40 academics at the museum were regularly leaving their machines on overnight for no reason.
"Some of them think they’ve switched off the computer when they’ve only switched off the screen", says Mr Moffett.
"It’s probably more ignorance than anything else. They’re not aware of the cost there is in leaving machines running."
Mr Moffett installed a simple bit of software that automatically switches idle machines off every evening, and did some new calculations to find out what he can expect to save.
His estimate? A whopping 25% – equivalent to more than $6,000 per year – with no sacrifice beyond the cost of the software.
Liverpool University has done the same thing with a much larger number of workstations, and claims to have saved itself 1,000,000 computer hours each month – equivalent to $400,000 a year.
The hungry giants of IT
Big as it is, the power drain of normal business desktops is dwarfed by the appetites of datacentres.
These warehouses contain thousands of servers that remain on 24/7 in order to service our growing need for cloud-based applications such as Google Apps, Salesforce and Microsoft’s new Office 365.
Globally, IT has been estimated to contribute 2% of humanity’s total CO2 emissions, although environmental pressure group Greenpeace believes this figure will rise – and points to datacentres as the main culprit.
However, recent research by Nucleus, a technology consultancy, suggests that cloud computing may be far more energy efficient than running applications on local computers.
Nucleus calculated that CO2 emissions could be almost halved by businesses running an application through the shared resources of a data centre rather than on their own local servers.
So, in a similar way to IMEC’s energy harvesting devices, there is some evidence that datacentres might actually pay their own way – at least in terms of their environmental impact.