[tomsaffell]

> I wonder if there's a converse effect?

If the inaccuracies are due to the meter's assumption around the current waveform then there probably is a way to exploit that. I suspect (from the little I have read) that the meters in question are: 1) assuming a sinusoidal current wave form, 2) assuming that the peak observed current is the peak of that sinusoidal wave, 3) effectively integrating under the area of the curve (with respect to voltage) to estimate total power. If all that's true, then to 'cheat' you'd need a device for which the current waveform looks like a 'fat' sine wave - same peak height, but wider peaks and steeper gradient through zero. In the extreme case it would be a square wave, but that might have too much harmonics.

For example, you could create a heater (a simple resistive load) that alters its resistance at 60hz. When the voltage reaches its peak the heater would have its 'normal' resistance, and during the next 1/4 cycle it would ramp down its resistance, reaching a resistive low as the voltage passes through zero, and then ramp up its resistance for the following 1/4 cycle until it reaches its 'normal' resistance at the peak 'negative' voltage (1/2 a cycle from where we started), then repeat over.

I think that would trick a meter that only looked at peak current and assumed a sinusoidal waveform. But who knows what other things it might break...

[takingflac]

This is called phase shifting(1) adding a large enough inductor to all of your resistive loads will cause your power factor(2) to drop. Unfortunately for you the power company bills you for your apparent power useage which takes into account both the real and imaginary parts of your power consumption, it measures your shifted loads.

1. http://www.learnabout-electronics.org/ac_theory/ac_ccts_51.p... 2.https://en.wikipedia.org/wiki/Power_factor