As the experimenter acknowledges this is an electrostatic generator. However it is an extremely weak one. Where this machine develops 2 volts a person can develop thousands of volts of electrostatic electricity by walking on a carpet under the right conditions.
To determine the actual POWER being produced one would multiply the volts times the amps measured in a stable circuit under load. In the video, voltage was measured in an open circuit hence no current and the current was measured under a short circuit hence no volts. In neither case is any POWER being generated.
The video states that there are 0.5 microwatts being generated by using the above measurements out of context.
Even if this best case scenario was true it would take ten million of these printed generators (check my math) to develop enough energy to power one 5watt LED.
Static electricity has its uses but powering electrical devices isn't one of them to my knowledge. Maybe lighting fluorescent bulbs.
RMS has taken the work others have started and developed it to another level.
Universities working on carbon super capacitors was one area he tinkered.
He improved on their work, eventually developing a conductive ink which he applied for patent on.
One of his projects developed 4 farad "per centimeter" capacitance value.
Adding this same carbon material to resins he developed a bullet resistant plastic.
Solar power by coating lexan with this carbon ink made clear panels that could generate electricity.
What is amazing is his ability to take existing technologies to new areas.