  Non intrusive load monitoring (NILM), or energy disaggregation, is the
process of separating the total electricity consumption of a building as
measured at single point into the building's constituent loads. Previous
research in the field has mostly focused on residential buildings, and although
the potential benefits of applying this technology to commercial buildings have
been recognised since the field's conception, NILM in the commercial domain has
been largely unexplored by the academic community. As a result of the
heterogeneity of this section of the building stock (i.e., encompassing
buildings as diverse as airports, malls and coffee shops), and hence the loads
within them, many of the solutions developed for residential energy
disaggregation do not apply directly. In this paper we highlight some insights
for NILM in the commercial domain using data collected from a large smart meter
deployment within an educational campus in Delhi, India, of which a subset of
the data has been released for public use. We present an empirical
characterisation of loads in commercial buildings, highlighting the differences
in energy consumption and load characteristics between residential and
commercial buildings. We assess the validity of the assumptions generally made
by NILM solutions for residential buildings when applied to measurements from
commercial facilities. Based on our observations, we discuss the required
traits for a NILM system for commercial buildings, and run benchmark
residential NILM algorithms on our data set to confirm our observations. To
advance the research in commercial buildings energy disaggregation, we release
a subset of our data set, called COMBED (commercial building energy data set).
