[Does anyone have comments on this? Anyone going to the conference in Idaho?]
Eric Dollard creates a 2000% energy return from standard wall power.
http://energyscienceconference.com/2014/05/05/2000-cop-20-0-reactive-power-as-energy-demonstration/
Nope. The discrepancy between real and reactive power exists, but shifting it around
decreases efficiency. Reactive power is something that you want to
eliminate, not increase. There are capacitative devices which will improve the power factor of the reactive loads in a system (the power factor is the ratio of real to apparent power - 100% PF means that all power is real, and none is reactive), which will reduce your energy usage. But, even if you could actually get a system to a 100% PF, you would still have the load of the real power.
Imagine a 100W light bulb and a 100W electric motor. Both draw the same power rating, but the light bulb draws solely real power, while the motor is a reactive device, so it draws some real and some reactive power (in reality, even the light bulb has some inductance, so it draws some reactive power, as well, but we'll pretend the light bulb is a perfect resistor). So, because it's partially-reactive, the motor might actually draw 120W. A power factor correction device will bring the motor closer to being non-reactive, so maybe it will only draw 105W - it will still have some reactive component, but that will be reduced.
Reactive power is the bane of AC power, and one of the few advantages of DC is that it eliminates the reactive power issue. It certainly does not offer a magical source of free energy. It
is good at wasting energy and burning things out.