Original URL: http://www.theregister.co.uk/2009/02/09/leaner_and_greener/

Green semiconductor advice goes beyond the chip

Cradle-to-cradle thinking

By Rik Myslewski

Posted in Hardware, 9th February 2009 21:01 GMT

ISSCC The semiconductor industry is poised to make major contributions to global energy efficiency, according to NXP Semiconductors chief technology officer René Penning de Vries speaking at the International Solid State Circuits Conference (ISSCC).

The need for energy efficiency is twofold, according to Penning de Vries speaking at the San Francisco, California, event. Namely, to reduce carbon dioxide emissions that contribute to global warming, and to reduce the overall need for the energy required to power electronic devices. This will, in turn, reduce the need for power generation and thus also reduce carbon emissions

"For every one per cent saved in the world's electricity consumption," said Penning de Vries, "roughly 40 fewer power stations are required."

Most energy efficiency efforts undertaken by the semiconductor industry up until now have focused on chips themselves. The next steps "require a new climate of innovation," which Penning de Vries defined as "cradle to cradle". That means design, though manufacturing, to use in carefully monitored operation with real-time, component-level, highly optimized power management.

Among the areas of improvements that Penning de Vries discussed were buildings, displays, lighting, and cars.

Buildings: approximately 2.5 billion electricity meters are currently in use worldwide. Unfortunately, most meters are primitive analog devices that must be read manually by a peripatetic meter-reader with a clipboard.

Networkable meters are only now beginning to appear, adding the advantage of centralized monitoring and immediate feedback to their users.

The next step will be smart metering using advanced metering infrastructure (AMI) - which Penning de Vries said in an aside to the assembled semiconductor designers will "require a lot of silicon."

AMI meters will be able to not only monitor and regulate electricity use, but also intelligently load-balance in real time, flattening out peak demand - which, according to Penning de Vries, is actually a rare occurance - only 55 hours per year, for example, in California.

Widespread adoption of AMI metering could result in a 10 per cent reduction in electricity use.

Displays: Penning de Vries referred to the current backlighting systems used in the majority of large-screen displays - think wide-screen LCD TVs - as "stupid." To illustrate the immediacy of the challenge, Penning de Vries claimed that: "As three million homes upgrade to home cinema, we need another - large - power station."

He outlined a number of proposed improvements that would reduce current power requirements by up to 85 per cent, yet still produce the same brightness as is achieved in today's systems.

All of his suggested improvements require monitoring the display's video signal to determine the color and brightness of each pixel, and then modify the power used for illumination on a pixel-by-pixel basis.

Merely using white LEDs as illumination, then dimming the illumination of white pixels could result in a 50 per cent power cut without changing perceived illumination, according to Penning de Vries. Adding RGB sensing and adjusting illumination to match pixel needs could drop that power by another 10 per cent.

Using RGB LEDs rather than white LEDs could drop power needs by 85 per cent when compared to today's backlighting, and adding ambient light sensors that adjust overall light output in relation to room lighting could drop needed power even further.

Lighting: according to Penning de Vries: "20 per cent of electricity produced globally is used for lighting; changing from incandescent lamps to compact flourescent [CFL] or tube lights [TL] can save 80 per cent of this."

"It's time to phase out Edison's invention," he said.

CFL technology remains rather primitive, and much could be accomplished by adding smart circuitry to their design, including such niceties as "compatibility with conventional phase-cut dimmer controls."

LED lighting offers comparable efficiency gains, and has the added benefits of long life (up to 30,000 hours) and low voltage requirements. Unfortunately, as Penning de Vries noted, LED lighting is still far too expensive for conventional use, and there are still color-temperature hurdles to overcome.

Cars: A full 50 per cent of all liquid fuel goes to transport, according to Penning de Vries - and that's despite the fact that fuel consumption per-car has decreased by 35 per cent over the past 30 years.

The IEA projects that "light-duty vehicles" - cars - could achieve another 50 per cent reduction by 2030 using smarter electronic control, more-efficient hybrids, and such driving aids as "adaptive cruise control using radar and lane-change sensors."

Electrical cars are all well and good, said Penning de Vries, but the source of their electricity can make them less efficient than even hybrid vehicles. A fully electric car that gets its juice from a coal-fired power plant has worse "cradle to cradle" energy efficiency than a hybrid, he said.

He also pointed out that while hybrid cars grab the headlines there are a multitude of electronic improvements yet to be made in conventional cars, such as moving from hydraulic to electrical systems in such components as transmissions and power steering, and installing electronic sensors in tires to monitor under-inflation. These, he claimed, account for "around five per cent of total motoring energy loss in the US."

Weight reduction could also benefit from moving all automotive wiring to a digital-network model. Penning de Vries said that a current "high-end" car's wiring harness can weigh between 40 to 80Kg. Since every 50Kg of weight reduction can save a tenth of a liter of fuel for every 100Km driven, weight-reduction efficiencies could add up quickly.

In conclusion, Penning de Vries said that: "The coming decades will see IC innovation with much greater focus on 'leaner and greener' applications. We will witness an evolution from low power for long battery life to low overall power consumption.

"The semiconductor industry - as other industries - can and will play its part in the drive to reduce global carbon dioxide emissions, and help reduce climate change."

And, of course, the industry will also design, manufacture, and sell a lot of new semiconductor-based products. ®