The article talks a lot about their rectifier and im guessing that's where the 'breakthrough' is, but still I feel this is like too many of these articles where its a lot of hype for a little progress.
It's almost certainly going to be milliamps or microamps unless you're inches from something. This isn't for cellphones and the like but for remote sensors and the like. I also bet they'll at least have to have a capacitor to store up extra charge for chirping back only sometimes.