A method of validating fundamental-only power measurements, the method comprising: selecting, by a meter testing system, a wideband voltage waveform from a plurality of predefined voltage waveforms, and a wideband current waveform from a plurality of predefined current waveforms, the wideband voltage waveform comprising a fundamental voltage component and a harmonic voltage component and the wideband current waveform comprising a fundamental current component and a harmonic current component; accessing, by the meter testing system, a wideband demand indicating an amount of power expected to be delivered by the wideband voltage waveform and the wideband current waveform over a period of time; accessing, by the meter testing system, a fundamental demand indicating an amount of power expected to be delivered by the fundamental voltage component and the fundamental current component over the period of time; calculating, by the meter testing system, an expected registration for a meter under test by comparing the fundamental demand to the wideband demand; measuring, from the meter under test, a measured registration by applying, at the meter testing system and to the meter under test, the wideband voltage waveform and the wideband current waveform, wherein the meter under test is configured to measure power consumption from the fundamental voltage component and the fundamental current component only; calculating, by the meter testing system, based on the expected registration and the measured registration, an error for the meter; and when the error is outside a tolerance, identifying the meter under test as non-compliant. selecting, by a meter testing system, a wideband voltage waveform from a plurality of predefined voltage waveforms, and a wideband current waveform from a plurality of predefined current waveforms, the wideband voltage waveform comprising a fundamental voltage component and a harmonic voltage component and the wideband current waveform comprising a fundamental current component and a harmonic current component; accessing, by the meter testing system, a wideband demand indicating an amount of power expected to be delivered by the wideband voltage waveform and the wideband current waveform over a period of time; accessing, by the meter testing system, a fundamental demand indicating an amount of power expected to be delivered by the fundamental voltage component and the fundamental current component over the period of time; calculating, by the meter testing system, an expected registration for a meter under test by comparing the fundamental demand to the wideband demand; measuring, from the meter under test, a measured registration by applying, at the meter testing system and to the meter under test, the wideband voltage waveform and the wideband current waveform, wherein the meter under test is configured to measure power consumption from the fundamental voltage component and the fundamental current component only; calculating, by the meter testing system, based on the expected registration and the measured registration, an error for the meter; and when the error is outside a tolerance, identifying the meter under test as non-compliant.