The majority of technological advancements associated with the electrical grid, and particularly the increasing use of non-linear loads and power electronics in the distribution network, a weak network, challenge the fundamental assumption that voltages and currents exhibit sinusoidal waveforms. As extensively discussed by numerous authors, the electrical grid undergoes changes for which there are no conceptual foundations, measurement techniques, or practical validation strategies to address basic tasks such as energy consumption measurement, control of distributed generators, or the effective implementation of electrical protections in the non-sinusoidal environment. While the IEEE 1459 standard exists for such cases, it encounters conceptual complications regarding reactive power, as well as practical limitations requiring a complete spectral decomposition that can only be performed offline, preventing its use in real-time processes. Therefore, this study scrutinizes available techniques for online electrical power measurement in typical electrical disturbance scenarios, comparing their accuracy, dynamic response, and effectiveness in terms of the aforementioned standard.