A method of using a power consumption measurement device: determining at least two first current sensor readings from the one or more main electrical supply conductors; calibrating the power consumption measurement device, comprising applying a Kalman filter; electrically coupling a first calibration load to the electrical power infrastructure; determining at least one second current sensor reading from the one or more main electrical supply conductors; re-calibrating the power consumption measurement device, comprising applying the Kalman filter; uncoupling the first calibration load from the electrical power infrastructure; determining at least one third current sensor reading from the one or more main electrical supply conductors; and determining a first electrical power used by the electrical power infrastructure of the structure. Other embodiments are disclosed.