Efficient estimation of power consumption is vital when designing large digital systems. The technique called power emulation can speed up estimation by implementing power models alongside a design on an FPGA. Current state-of-the-art power emulation methods construct models using various custom techniques, but there is no study on how the existing methods relate to each other nor how their differences impact the final quality of the model. We propose a methodology which describes the breadth of current approaches to automated construction of power emulation models. We also evaluate the current methods, finding that there is significant variation in accuracy and complexity. In 32.8 % of all tests, the average accuracy of the least complex m...