rather than installing a power monitoring meter on
each device within a building, software can instead
analyse and determine which devices on a property
are in use based on the power signatures found within
an aggregate power data set for an entire home, or
business.
Power producers will be able to monitor a home,
or business, and understand which devices can be
cycled during peak loads to relieve grid pressure,
especially in high energy consumption areas like
urban centres where large percentages of a population
tend to live. In order to accomplish this, a device is
needed to record a consumer’s power usage. A pilot
program has been created at the University of Hawai’i
that currently involves monitoring aggregate power
usage from 20 homes on the island of Oahu using a
smart power meter (SPM). The components,
challenges and scalability of the pilot system will be
discussed, as well as future work pertaining to
demand response programs, which will be discussed
in the following sections.
1.2 Related Research
The study and feasibility of demand response as it
relates to power grids is ongoing, and the pilot
program looks to contribute to that research in the
areas of large data collection, storage and analysis
(FERC 2008, NAERC 2007).
Demand response programs allow for increased
peak load reduction as well as the ability to balance
supply and demand of energy in power grids (FERC,
2008). Stability and load shifting are two factors that
are important in maintaining grid stability, which can
be accomplished through demand response programs.
Cost efficiency is another benefit of demand response
because there is no need to maintain spinning reserves
and large power storage infrastructure (NREL 2012).
Similar research is being done on smart meters to
collect and analyse data. A group from the University
of Bath investigated the use of smart metering devices
in combination with voltage control techniques. Their
re-search focused on analysing the consumer side of
demand response as a way to create cost efficiency
for a consumer as well as a tool to restore grid system
faults and maintain transmission stability. The Lon
Local Operating System (LonWorks) and ZigBee
Wireless Network Standard were two suggestions for
creating a system of communication between smart
meters and controllers to handle real-time data (Gao
and Redfern, 2011).
A research group in Europe proposed the use of
local area networks (LAN) and wireless local area
networks (WLAN) in combination with KNX
communication standards as an option to set up
communication between smart metering devices. The
use of ZigBee and KNX components were deemed
feasible to monitor load consumption of devices in
order to create a timetable of shiftable loads. The load
shifts refer to the rescheduling of device usage from
peak hours to times that do not provide large strains
on the grid. Real-time analysis and visualization
would allow consumers to make the proper choices in
energy consumption that are related to cost
efficiency. An algorithm based on tariffs was the
basis for the load timetables (Kunold et al., 2011).
Researchers in Canada proposed a smart metering
system based on load disaggregation where a power
signal is analysed into the various device components
that produce it. Their research focused on the factors
that affect load disaggregation such as noisy signals,
simultaneous loading, computational costs and
privacy issues. They noticed that devices produced
different power signals when cycled, for example,
constant vs. periodic loads. To train algorithms in
detecting a device, the research group suggested
algorithm training based on probabilities and the
clustering of individual devices. The research group
deemed the definition of deferrable actions as
necessary in their proposed system. Deferrable
actions are those relating to devices whose utilization
is not a priority and cycling can instead be scheduled
at an alternative time, which would allow for load
shedding. These devices include washer/dryers,
ovens and dishwashers (Makonin, 2013).
A UK-based power utility, National Grid, looked
into the affect the power usage of certain devices had
on the grid. They found that millions of kettles are
cycled around 5pm, knowledge such as this allows a
utility to know when to cycle specific loads within
home. National Grid uses the aforementioned
knowledge to maintain grid frequency. Aggregating
these cycling patterns with the loads of other houses
in a neighbourhood, or region, allow for the ability to
maintain grid stability throughout sections of a power
grid (National Grid, 2015).
2 SPM PILOT SYSTEM
Because of the island’s geography and dense
population, Oahu provides an ideal location to
understand renewable energy penetration into an
existing power grid, and how it relates to demand
response programs. Several factors allow for Oahu to
be the location to implement the pilot system, these
factors include high solar radiation on the island,
access to a dense urban populations, and Oahu being