The invention is a method for measuring and 
processing a plurality of electrical parameters of a common 
alternating current (AC) service that supplies multiple different 
electrical devices such that the power use rate and total power used by each of multiple devices is determined. Sensors provide 
high resolution signals corresponding to the current and 
voltage of the 
AC power supplied to the service panel typical of those used in residential construction. Analog-to-
digital conversion and 
processing circuits determine multiple electrical parameters with 
high resolution at a sampling rate sufficient to determine the electrical parameters for approximately each AC cycle. The electrical parameters are stored as a large 
data set in a memory with sufficient capacity to store several months of electrical parameters representing each AC cycle. The 
data set is processed to extract complete on-off cycles of the devices. The on-off cycles are represented by instance structures. The characteristics of the instance structures are used to determine device structures. Each device structure characterizes one of the multiple devices. The contributions associated with the extracted instance structures are subtracted from the 
data set, making is possible to extract additional instance structures from the residual information in the data set. Information from the device structures are used to help extract instances structures that are partially obscured by overlapping instance structures. The newly extracted instances structures are subtracted from the data set and 
processing continues until no more instance structures can be extracted. Information from the extracted instance structures and device structures are further grouped and processed to provide useful information reports to a 
consumer. As the electrical parameters are determined and added to the data set, they can be incrementally processed so that near real 
time information can be provided to the 
consumer. The cost of operating each device and other information enables the 
consumer to make informed decision regarding energy use and conservation.