Seems like a potential nightmare when your sensor network's operation is contingent on one badly tuned power circuit in a crappy Chinese LED floodlight in the janitors closet being perpetually left on.
It is not just ambient electrical noise that contains usable energy. Others have demonstrated practical sensor energy harvesting from ambient WiFi and ambient broadcast TV signals. I'd expect that the Sony device can probably use those too, so if you've got WiFi in your building you should be fine.
If there is ambient radio, you can also use that for extremely low power data transmission from your sensors. The trick there is to not actually transmit any of your own energy. You instead either absorb or reflect the ambient radio. This is called backscatter communications.
Here is a video showing a demonstration of both energy harvesting from ambient radio and backscatter data transmission [1].
If you use WiFi signals as your ambient radio for backscatter, the research group in that video has also demonstrated that you can make your backscatter data stream match standard WiFi protocols so that you can use ordinary WiFi equipment for the receiver.
The above was fairly short range, but even so there are a lot of interesting applications. For instance you might want to have moisture sensors inside a wall to detect water leaks early. If your sensors are powered by ambient EM energy (noise or radio), you don't have to limit the sensors to places where you can easily reach them later to change batteries. They are fine if they are behind brick or drywall with no openings.
Seems like an interesting way to identify machines that are breaking down.
If these devices can be built cheaply, just place them all over a factory, chirping their ID whenever they have enough power to do so. You map the IDs to locations and get a real-time map of where there's EM noise spitting out. When the map starts changing from it's usual patterns, then you identify the source of that change.
Reminds me of a neat video I saw once on the inner workings of a sheet metal stamping factory (for car parts). They used a directional microphone array pointed at the inspected machine and compared audio waves and overlayed “hot spots” on a display to see how the machine was working and where it was malfunctioning.
Don't worry, by the time you work out the source of your data outage, Sony will have a wireless power module to sell you as well. It will be wildly inefficient however, so you'll want to only run it when there is actually a data outage. By the time you work that out, there will be orchestration services available that notice the outage and respond by temporarily flipping on the wireless power module. A sensor on one side of the room driving a machine on the other side, and somehow we've got it dependent on a cloud service on the other side of the planet. The future is looking bright.
Question is whether this could harvest enough energy to store it in a small battery to continuously provide power. But really sounds frightening if you change the setup of a few appliances and then suddenly half of your autonomously powered devices don't get enough power anymore because the noise is not high enough anymore.
could be very useful in-doors where solar is not possible and wiring is not practical. A lot of sensors do not have to be on all the time - occasional reading is more than enough.
