4 ms·

Wait, isn't this all free energy, waiting to be harvested?

creshal 10y ago
What's the efficiency of RF harvesters? 1%? 5%? Not worth it.
kqr 10y ago
Going along with the metaphor of the submission: sure, in the same way you can plant a solar cell on your roof and get "free energy" from the light pollution during the night if you live in a city. Or, literally, the energy is way too low to benefit from it. Sure, the TV might blanket space with a few watts of interference, but going by the law of quadratic decay that's not worth much at distance. All this noise does is prevent observation of low-energy signals. It does not contribute to a high-energy signal itself. (Goes for both light pollution and RF noise.) Edit: unless, of course, you mean we can "harvest" this free energy by making our appliances conform to regulations, in which case it's an obvious yes.
cbd1984 10y ago
Yes, which raises one possible way of fighting it: Make electronics manufacturers adhere to power efficiency ratings. The moment they have to care about how power efficient their gear is, they'll look at everywhere power's being wasted by, I don't know, being broadcast into the air for absolutely no good reason.
- MertsA 10y ago
  That's probably not going to be effective. Look at devices with cheap universal motors and the like. They spew out tons of noise and a lot of them have a filter on the input to cut down on noise but as far as decreasing wasted power, the RF noise is a tiny drop in the bucket compared to the total power of whatever power tool or vacuum we're talking about. Also, the filter that they put on the input to try to combat this doesn't increase the efficiency of the device. If anything, I'd be afraid that there would be design changes to decrease the thermal losses of a device even if it increased the noise it put out.
chiph 10y ago
I built a Tesla coil in middle school. I was able to get a 3' long fluorescent bulb to light up at distances of over 10' away. I also knocked out radio and TV reception for the entire block when it was on. Oops.

What's the efficiency of RF harvesters? 1%? 5%? Not worth it.

kqr 10y ago

Going along with the metaphor of the submission: sure, in the same way you can plant a solar cell on your roof and get "free energy" from the light pollution during the night if you live in a city. Or, literally, the energy is way too low to benefit from it. Sure, the TV might blanket space with a few watts of interference, but going by the law of quadratic decay that's not worth much at distance. All this noise does is prevent observation of low-energy signals. It does not contribute to a high-energy signal itself. (Goes for both light pollution and RF noise.) Edit: unless, of course, you mean we can "harvest" this free energy by making our appliances conform to regulations, in which case it's an obvious yes.

cbd1984 10y ago

Yes, which raises one possible way of fighting it: Make electronics manufacturers adhere to power efficiency ratings. The moment they have to care about how power efficient their gear is, they'll look at everywhere power's being wasted by, I don't know, being broadcast into the air for absolutely no good reason.

MertsA 10y ago
That's probably not going to be effective. Look at devices with cheap universal motors and the like. They spew out tons of noise and a lot of them have a filter on the input to cut down on noise but as far as decreasing wasted power, the RF noise is a tiny drop in the bucket compared to the total power of whatever power tool or vacuum we're talking about. Also, the filter that they put on the input to try to combat this doesn't increase the efficiency of the device. If anything, I'd be afraid that there would be design changes to decrease the thermal losses of a device even if it increased the noise it put out.

chiph 10y ago

I built a Tesla coil in middle school. I was able to get a 3' long fluorescent bulb to light up at distances of over 10' away. I also knocked out radio and TV reception for the entire block when it was on. Oops.