Smart metering infrastructures collect data almost continuously in the form
of fine-grained long time series. These massive time series often have common
daily patterns that are repeated between similar days or seasons and shared
between grouped meters. Within this context, we propose a method to highlight
individuals with abnormal daily dependency patterns, which we term evolution
outliers. To this end, we approach the problem from the standpoint of
Functional Data Analysis (FDA), by treating each daily record as a function or
curve. We then focus on the morphological aspects of the observed curves, such
as daily magnitude, daily shape, derivatives, and inter-day evolution. The
proposed method for evolution outliers relies on the concept of functional
depth, which has been a cornerstone in the literature of FDA to build shape and
magnitude outlier detection methods. In conjunction with our evolution outlier
proposal, these methods provide an outlier detection toolbox for smart meter
data that covers a wide palette of functional outliers classes. We illustrate
the outlier identification ability of this toolbox using actual smart metering
data corresponding to photovoltaic energy generation and circuit voltage
records