  Non-intrusive load monitoring (NILM) or energy disaggregation, aims to
disaggregate a household's electricity consumption into constituent appliances.
More than three decades of work in NILM has resulted in the development of
several novel algorithmic approaches. However, despite these advancements, two
core challenges still exist: i) disaggregating low power consumption appliances
and ii) distinguishing between multiple instances of similar appliances. These
challenges are becoming increasingly important due to an increasing number of
appliances and increased usage of electronics in homes. Previous approaches
have attempted to solve these problems using expensive hardware involving high
sampling rates better suited to laboratory settings, or using additional number
of sensors, limiting the ease of deployment. In this work, we explore using
commercial-off-the-shelf (COTS) power line communication (PLC) modems as an
inexpensive and easy to deploy alternative solution to these problems. We use
the reduction in bandwidth between two PLC modems, caused due to the change in
PLC modulation scheme when different appliances are operated as a signature for
an appliance. Since the noise generated in the powerline is dependent both on
type and location of an appliance, we believe that our technique based on PLC
modems can be a promising addition for solving NILM.
