Live from Pop!Tech: John Shearer -- Powercast Sends Power Through Air
by Team Treehugger, Worldwide on 10.19.07
More Pop!Tech geniosity...catch it live here.
Holy Jetsons! Powercast is developing technologies that send power through the air. That's right; they call it Powercast Wireless Power Platform, and it can recharge batteries using the existing radio frequencies already in the air.
As John noted, in the US alone, more than 350 million rechargeable batteries are purchased annually to power wireless sensors, cell phones, computer peripherals and other devices. Continuous recharging of batteries via the Powercast Wireless Power Platform has the potential to reduce the huge waste stream of batteries to a mere trickle. And early tests suggest it really works. More below the fold...
John noted that we've done similar things as long as 100 years ago.
Powercast is going to be this big...just kidding.
He suggested it'll take 10, 20, 30 years or so before we will be able to harvest radio frequency in really meaningful ways, but at this point here's how it works: a "Powercaster" plugs in to your wall and sends out a radio frequency, ready to be harvested; the radio waves bounce around the room, changing frequency as they hit walls and objects and tiny receivers implanted in your devices "hear" the frequencies, capturing up to 70 percent of the available energy.
Is this dangerous? John noted that the waves were similar to a cellphone next to your ear.
One of the demo projects was for a penguin exhibit. The temperature sensors in the exhibit had to use batteries and due to the cold would need to be replaced often. This was a hassle and expensive. Powercast was able to charge these batteries via the air and as such avoid this problem. Check out more at their site. ::Powercast and ::Pop!Tech
Tesla would be proud.
I don't see the reasoning that this would reduce the waste stream of rechargeable batteries, by charging wirelessly as opposed to (much more efficient) direct charging.
This technology uses/wastes a good deal of power.
The transmitter uses power, and the power that is actually received by the device is only a fraction of what it would get if directly plugged into a wall socket.
How is this green? I'm skeptical that 70% of the energy can be captured, but even if this is true, this represents a great deal of electricity wasted. When you can get close to 100% of the power from the socket to your device via a wire, why waste all that electricity for the convenience of not having to plug in a cord.
Assuming a 70% efficiency of transmission, devices will now require 143% as much power to run. If the device transmits power at 50% efficiency, you've just doubled your electrical demand--and carbon dioxide emissions.
There's not much real information on their web site, but if you read carefully, they say they capture 70%....but it's not 70% of the energy consumed by the transmitter--it's 70% of the theoretical maximum, which is probably less than 1% of the power they consume. Rechargeable batteries are a lot better than that.
Doesn't it freak anyone else out to hear "it's similar to holding a cell phone next to your ear"?!?!
I don't trust having the cell phone beaming next to my ear, and he's suggesting having that sort of wave bouncing around your living space, 24/7? And what about people living NEAR you using it - does that mean you're exposed to those waves, too?
I'm a bit sick of MORE technology being the "answer" to environmental problems. And I'm obviously not a Ludite - I'm on a computer right now, after all.
Yeah, 70% of the energy that actually hits that little receiver. Meanwhile, 99% of the power being broadcast goes in some other direction, and is wasted. Without some kind of directional focus, broadcast power is incredibly inefficient.
I guess it comes down to a debate about whether the "waste stream" of the batteries (which are recyclable, but most people don't bother) is worse than broadcasting 100 times the power you actually need in all directions so that one (or more) devices can capture the amount of the power they need.
Would this mean that the batteries are always drawing energy, even after they've reached "fully charged"? That just seems wasteful to me, especially if we apply it to larger appliances. Already, appliances left plugged in generate 54 million tonnes of CO2 per year - in the UK alone. This seems like it is going the opposite direction of Treehugger's mission.
Indeed, this does sound incredibly wasteful... maybe if we were getting all of our energy from renewable sources, but that's a long way off if it's ever even going to happen.
But could this technology be somehow applied to make a portable electronics charger? How much power is just flying around from radio stations and the like? Would catching that power be enough to perhaps slowly charge something small like a cell phone or an MP3 player?