Cree Introduces an LED Bulb Edison Would Love

Technology Review has an article on a new LED light design that mimics the old incandescent bulb - Cree Introduces an LED Bulb Edison Would Love.

If you’ve had any experience with LED light bulbs, you know they can look pretty odd. Cree today introduced a bulb that mimics the traditional incandescent bulb design in every way–except its inefficiency.

The bulb is the first consumer bulb from Cree, which primarily supplies LED semiconductors to other lamp makers. There are three products: a 40-watt equivalent and two 60-watt equivalents with different color light. They’re available from Home Depot online now and will be made available in stores this month priced between $9.97 and $13.97.

What’s most notable is that bulbs have the same glass dome as incandescent lights and there isn’t a large metal heat sink. The first wave of general-purpose LED products have heavy metal fins to wick away heat from the LED light sources, which helps ensure life. The Cree bulb uses the same glass as an incandescent but has a rubber coating to prevent shattering.

In an incandescent bulb, a tungsten filament in the center of the glass glows to give off an even, warm light. Cree designed a “filament tower” that places a series of pin-hole-shaped LEDs in the same location as the traditional filament. I installed one yesterday and the effect is a similar light output as a traditional bulb and even light distribution.

Having a familiar shape is very important to spur more consumers to consider LEDs as a replacement for incandescent bulbs, says Mike Watson, the vice president of corporate marketing. “Consumers actually love that particular (incandescent bulb) product. It’s the shape they’re used to and it gives off a warm glow they expect, but it’s grossly inefficient and has a short lifetime,” he says. Cree’s bulb uses high-power LEDs which means it can work with a smaller heat sink, which appears like a collar around the base of the bulb.

An incandescent bulb lasts about 1,000 hours, while most LED bulbs are rated to last 25,000 hours, which can be 15 or 20 years depending on usage. The Cree bulb has a 10-year warranty.

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US Vehicle fuel economy up for the first time since March

PhysOrg has an interesting graphic showing vehicle fuel efficiency in the US - Vehicle fuel economy up for the first time since March.

Average fuel economy (window-sticker values) of cars, light trucks, minivans and SUVs purchased in August was 23.8 mpg, the fourth-best month on record and an 18 percent increase (3.7 mpg) from October 2007, the first month of monitoring by UMTRI researchers Michael Sivak and Brandon Schoettle. The improvement from July to August—0.2 mpg—most likely reflects the increased price of gasoline, they say.

In addition to average fuel economy, Sivak and Schoettle issued their monthly update of their national Eco-Driving Index, which estimates the average monthly emissions generated by an individual U.S. driver. The EDI takes into account both vehicle fuel economy and distance driven—the latter relying on data that are published with a two-month lag.

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3-D Transistors

Technology Review has a look at energy efficient advances in chip design - 3-D Transistors.

In an effort to keep squeezing more components onto silicon chips, Intel has begun mass-producing processors based on 3-D transistors. The move not only extends the life of Moore's Law (the prediction that the number of transistors per chip will double roughly every two years) but could help significantly increase the energy efficiency and speed of processors.

The on-and-off flow of current in conventional chips is controlled by an electric field generated by a so-called gate that sits on top of a wide, shallow conducting channel embedded in a silicon substrate. With the 3-D transistors, that current-carrying channel has been flipped upright, rising off the surface of the chip. The channel material can thus be in contact with the gate on both its sides and its top, leaving little of the channel exposed to interference from stray charges in the substrate below. In earlier transistors, these charges interfered with the gate's ability to block current, resulting in a constant flow of leakage current.

With virtually no leakage current, a transistor can switch on and off more cleanly and quickly, and it can be run at lower power, since designers don't have to worry that leakage current could be mistaken for an "on" signal.

Intel claims the new transistors can switch up to 37 percent faster than its previous transistors or consume as little as half as much power. Faster switching means faster chips. In addition, because of their smaller footprint, the transistors can be packed closer together. Signals thus take less time to travel between them, further speeding up the chip.

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Reviewing Jevons' Paradox

Wired has a look at the accuracy of Jevons Paradox and the implications for energy efficiency strategy - Clive Thompson on Unsaving the Planet.

We put a lot of stock in energy efficiency. It is regarded as the quickest and easiest way to reduce carbon emissions. Al Gore even ended An Inconvenient Truth with a plea for everyone to install low-power lightbulbs and appliances.

But in 1865, British economist William Stanley Jevons offered a skeptical take on efficiency. In The Coal Question, he wrote that energy-efficiency technology has a backlash effect. By increasing efficiency we make energy cheaper, thus spurring people to use more of it. As Jevons pointed out, when steam engines became more efficient, the consumption of coal (for steam production) didn’t decrease—it expanded, because steam engines became cheaper to run and thus attractive for more and more things.

Adherents call this the Jevons paradox, or rebound effect. And the idea is at the heart of David Owen’s new book, The Conundrum, which argues that not only will efficiency fail to solve global warming—it’ll actually make things worse. The good news is that Owen’s analysis is likely off target. But it’s worth hearing him out.

Owen makes a number of grim observations that ring true. Automobile engines have become much more efficient, but we’ve responded by demanding larger cars loaded with more electrical gewgaws. Air-conditioning has become more efficient, but we’ve made it a cultural norm that every room and vehicle nationwide must be cooled in summer.

Or consider lighting. As a source of illumination, light from modern bulbs costs just 0.03 percent of what candles did in 1800. But a recent study funded by the US Department of Energy found that the amount of global GDP spent on lighting has remained at about 0.72 percent over the past three centuries. The astonishing increase in lighting efficiency merely drove an explosion in the number of things we light up—like kids’ sneakers. Efficient power usage has made it “so that there’s almost nothing you can do that doesn’t require power,” as Owen tells me.

But if efficiency will just make things worse, how can we avert climate disaster? Owen says we need to start living smaller, quickly and dramatically—by traveling less and consuming less and taxing energy much more. It is not, he admits, a pleasant message.

Assuming he’s correct. The Jevons paradox has long been controversial, with economists arguing that Jevons got it wrong. Rebound effects are real, they say, but much smaller than he believed.

That’s because we modern folk spend very little on energy—only around 9 percent of GDP in the US. Plus, if we save money through energy efficiency, we don’t immediately spend those savings solely on more energy. We spend it on more food or movies or clothes, where energy accounts for only a small part of creation cost. As a result, economist James Barrett calculates, rebound probably decreases the total amount of energy saved by at most 30 percent—hardly the catastrophe predicted by Jevons and Owen.

There’s also evidence that efficiency standards work. After California imposed them in 1974, per capita electricity consumption stopped growing, even as it rose throughout the rest of the nation. Yes, globally we chew through more power every year, but that’s due to economic growth, argues Amory Lovins, an environmental scientist with the Rocky Mountain Institute.

Owen and other rebound Cassandras “have a critique of growth, which they then blame on energy efficiency,” Lovins tells me. But perhaps we’re buying two air conditioners simply because we’re wealthier, not because air conditioners are more efficient.

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Low-Cost Tablet Runs on Three Watts of Power

Technology Review has an article on a new low power technology for portable devices - Low-Cost Tablet Runs on Three Watts of Power.

After a year of testing in a remote village in India, researchers are ready to scale up production of an ultra-low-power $35 tablet called the I-slate.

The I-slate is designed to teach math and other subjects to students whose schools lack electricity or to students who don't have access to teachers at all. The device will enter full-scale production next year, and will be the first device to apply a low-power technology called probabilistic CMOS (complementary metal-oxide semiconductor) to achieve a longer battery life.

The probabilistic CMOS approach is simple: run an ordinary microchip less stringently, sacrifice a small amount of precision, and get huge gains in energy efficiency in return. Probabilistic CMOS (CMOS refers to the technology behind most of today's chip technologies) works particularly well in graphics and sound processing, since human vision and hearing aren't perfect, and small errors are therefore undetectable.

Krishna Palem, a professor at Rice University and director of the Institute for Sustainable Nanoelectronics at Nanyang Technological University, first demonstrated probabilistic CMOS in 2006. Palem is now working on getting the technology into applications including a low-power hearing aid. In the educational tablet device, Palem says, probabilistic chips will enable huge power savings: the educational tablet will require just three watts of power, meaning it can be powered entirely by small solar cells like those on a pocket calculator.

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