Scientists Working On Infrared-Based Renewable Energy

Scientists Working On Infrared-Based Renewable Energy -  Infrared: A new renewable energy source?
    HARVARD PHYSICISTS PROPOSE A DEVICE TO CAPTURE ENERGY FROM EARTH’S INFRARED EMISSIONS TO OUTER SPACE

    By Caroline Perry

    When the sun sets on a remote desert outpost and solar panels shut down, what energy source will provide power through the night? A battery, perhaps, or an old diesel generator? Perhaps something strange and new.

    Physicists at the Harvard School of Engineering and Applied Sciences (SEAS) envision a device that would harvest energy from Earth’s infrared emissions into outer space.

    Heated by the sun, our planet is warm compared to the frigid vacuum beyond. Thanks to recent technological advances, the researchers say, that heat imbalance could soon be transformed into direct-current (DC) power, taking advantage of a vast and untapped energy source.

    Their analysis of the thermodynamics, practical concerns, and technological requirements will be published this week in the Proceedings of the National Academy of Sciences.

    “It’s not at all obvious, at first, how you would generate DC power by emitting infrared light in free space toward the cold,” says principal investigator Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at Harvard SEAS. “To generate power by emitting, not by absorbing light, that’s weird. It makes sense physically once you think about it, but it’s highly counterintuitive. We’re talking about the use of physics at the nanoscale for a completely new application.”

    Challenging convention

    Capasso is a world-renowned expert in semiconductor physics, photonics, and solid-state electronics. He co-invented the infrared quantum-cascade laser in 1994, pioneered the field of bandgap engineering, and demonstrated an elusive quantum electrodynamical phenomenon called the repulsive Casimir force—work for which he has received the SPIE Gold Medal, the European Physical Society Prize for Quantum Electronics and Optics, and the Jan Czochralski Award for lifetime achievement. His research team seems to specialize in rigorously questioning dated assumptions about optics and electronics.

    “The mid-IR has been, by and large, a neglected part of the spectrum,” says Capasso. “Even for spectroscopy, until the quantum cascade laser came about, the mid-IR was considered a very difficult area to work with. People simply had blinders on.”

    Now, Capasso and his research team are proposing something akin to a photovoltaic solar panel, but instead of capturing incoming visible light, the device would generate electric power by releasing infrared light.

    “Sunlight has energy, so photovoltaics make sense; you’re just collecting the energy. But it’s not really that simple, and capturing energy from emitting infrared light is even less intuitive,” says lead author Steven J. Byrnes (AB ’07), a postdoctoral fellow at SEAS. “It’s not obvious how much power you could generate this way, or whether it’s worthwhile to pursue, until you sit down and do the calculation.”

    As it turns out, the power is modest but real.

    As Byrnes points out, “The device could be coupled with a solar cell, for example, to get extra power at night, without extra installation cost.”

    Two proposed devices—one macro, one nano

    To show the range of possibilities, Capasso’s group suggests two different kinds of emissive energy harvesters: one that is analogous to a solar thermal power generator, and one that is analogous to a photovoltaic cell. Both would run in reverse.

    The first type of device would consist of a “hot” plate at the temperature of the Earth and air, with a “cold” plate on top of it. The cold plate, facing upward, would be made of a highly emissive material that cools by very efficiently radiating heat to the sky. Based on measurements of infrared emissions in Lamont, Oklahoma (as a case study), the researchers calculate that the heat difference between the plates could generate a few watts per square meter, day and night. Keeping the “cold” plate cooler than the ambient temperature would be difficult, but this device illustrates the general principle: differences in temperature generate work.

    “This approach is fairly intuitive because we are combining the familiar principles of heat engines and radiative cooling,” says Byrnes…

First look at notifications feature on Apple TV arrives for iTunes SXSW Festival

Apple might have just gave us our first glimpse at an upcoming notifications feature coming to the Apple TV. During Apple’s live stream of its iTunes Festival at the SXSW festival in Austin tonight, Apple for the first time started prompting users to tune into the live stream with a notification feature on the Apple TV (pictured above). The notification interrupts the currently-playing content— in my case a video AirPlaying from my Mac— and displays a notification asking users if they would like to watch the live performance.

Back in December when we gave you a behind-the-scenes look at development of Bloomberg’s new Apple TV app, we reported first that Apple and its partners were planning on introducing a new notification feature that would deliver “tune-in alerts” to users through both the Apple TV and companion iOS apps. The feature described to us by the development team working on Bloomberg’s Apple TV app sounds a lot like the notification that Apple started sending out for the iTunes Festival on Apple TV tonight.

Rather than present iTunes Festival branding, the notification is quite generic and simply says “Live Show in Progress – Performing now: Pitbull. Would you like to watch this live show?” It then gives users the option to “Watch Now” or “Cancel.” It definitely appears to be a system-wide feature that Apple could easily expand to any app rather than something specially designed for the iTunes Festival.

In January we reported that Apple was testing new Apple TV harware that could include a revamped operating system and possibly app and game support for sometime in the first half of 2014. We also reported that Apple was testing upgraded hardware that included built-in AirPort Express 802.11ac router functionality and versions that include a built-in TV tuner to control existing cable boxes. More recently we reported that code in builds of iOS 7 points to refreshed hardware, at least internally. Bloomberg and others later confirmed many of the same details and said the hardware would be unveiled next month ahead of a Christmas unveiling.

Climbing out of those towering deserts

In Palos Verdes, the cliffs overlook the assortment of beaches and coves like a weaving terrace of basalt and shale, layered with skeletons – the
strata of prehistory.

Climbing out of those towering deserts are bushes and trees.  Dry, salt-ridden and barbed, they harbor living creatures above the ocean, for all their inhospitality.

Not long ago I was watching the sea, standing by the cliffs, when I heard a bird singing close by.  It was balanced on a gorse bush; singing with such passion, with such blithe intensity that it didn’t notice how close I really was.  I was near enough to see the muscles of its throat fluttering, to see the small, sharp beak open to release the notes into the air.  I was able to visualize the music, tiny filigrees and arabesques twisting in an invisible fabric:  lilting and lowering, as the bird saw fit, to suit the musicale its joyous blood would dictate.

In the city, where I live, I have been hearing music too.  Pale and plaintive, it rises with the morning, a lavender echo of breaking clouds and a sunrise swathed in watercolor.  A mourning dove – always alone – rests on a telephone wire, its sadness filling the air.  All I see is the dark silhouette, but I know well the prism of its feathers:  mauve, grey and lilac:  the accepted dress colors for Victorian ladies in half-mourning.  Though there is only one, its mate is undoubtedly nearby.  Whether they are collecting materials for their nest, or scouting for new real estate, their impatient DNA urges them on.