IEEE Electrification Magazine - December 2016 - 41

comfort and convenience. The demo
was one of the first efforts to provide
and have loads respond automatically to pricing data on a very short timescale-every 5 min compared to
other demos' 15 min-and the first to
include the true costs of transmission
and distribution within that price by
doing in-the-field demand response
with real-time prices.
From early 2006 through March
2007, PNNL also managed the Grid
Friendly Appliance Project, a field
demonstration of an autonomous,
grid-responsive controller called the
Grid Friendly Appliance controller.
This device is a small electronic controller board that autonomously
detects underfrequency events and
requests that load be shed by the
appliance that it serves. I mention
this because much of the discussion
around transactive energy often
focuses on load management and
basic power sales, but as discussed
in the "IEEE Grid Vision 2050" report
there are three things you can do
with electricity: make it, move it, or
use it. Everything we do involves
these simple actions, and that
includes things like frequency and
voltage regulation.
In anticipation of the applicability
of transactive energy systems to
emerging challenges in grid integration, the GridWise Architecture
Council (GWAC) began to build a
community of practice in the area of
transactive energy systems in May
2011. Starting with a workshop, the
council brought together a dozen
interested researchers and practitioners from utilities, vendors, labs, and
academia to compare their approaches and experience to create common
definitions and understanding within this topical area.
The council has continued this
work with additional topical workshops and has organized three
International Conference and Workshop on Transactive Energy Systems.
The changes at the edge of the grid
are here. They are making a differ-

ence. The communications and computing capability are here. The lessons
learned are here. The capabilities for
smart buildings and building control
systems are here. The interest is here.
My limited understanding of metaheuristics suggests that buildings represent the next big step forward. But
before we go looking for a problem to
solve just because we have a good
solution, let's step back and look at
why we need more buildings interoperating with the electricity grid.

Why do We Need a more
responsive Grid?
As more and more distributed energy
resources (DERs) penetrate distribution systems and more microgrids
and campus networks appear (as well
as entities such as virtual power
plants), the potential for these and
other entities, such as prosumers and
smart buildings and smart equipment, to interact with each other will
increase, requiring more decentralization and more coordination.
The GWAC's transactive energy
infographic (Figure 1) depicts the evolving interactive behavior of customers
and utilities. In the center of the diagram (the epicenter of change) is the
distribution system operator (DSO). In
this scenario, the DSO takes on the
responsibility for balancing supply and
demand variations at the distribution
level and linking the wholesale and
retail market agents (for more background, I recommend reading Kristov
and De Martini).
Another way of thinking about the
integrated distributed electricity system is through the concept of distributed reliability. This concept refers to a
federated reliability paradigm in which
DSOs-and potentially microgrids and
self-optimizing customers, enabled by
diverse small-scale generation, energy
storage, power flow control devices,
demand response, and other DERs
combined with advanced information
and control technologies-have
responsibility and accountability for
the reliable real-time operation of the

respective electric systems under their
operational control. Elements of this
federated system may adopt islanding
capability to enhance local resilience to
maintain electric service under stress
conditions on other parts of the electric system. Such a system requires
integrated operational processes and
distributed control systems to ensure
reliability (Taft et al.). Where we find
large users of power with control systems and motivation to optimize value
and economics, we ought to find an
opportunity to help. That sounds like a
role for smart buildings to me.
With perhaps some satirical foresight, Dave Barry asked the question,
"What in the world is electricity, and
where does it go after it leaves the
toaster?" I mention this because it
brings up an excellent point. With generation at the edge of the grid, we are
now seeing power flows in multiple
directions on networked systems and
bidirectional flows on radial systems.
The toaster itself may not be generating power, but the building where it is
located could be, which is why DSOs
will be needed to coordinate distribution power systems and the interaction
with the bulk power system.

How can We make the Grid
more responsive?
The prices of alternative energy and
renewable resources continue to
trend down, while their efficiency
continues to improve. Government
incentives and renewable energy
standards are mandating and promoting an ever-increasing adoption
of alternative energy projects to meet
the country's electricity needs. Microgrids are indicative of another approach to alternative energy adoption.
Distributed electricity generation
means decentralizing electricity production and creating the energy closer to where it is used. While this
approach lacks the economies of scale
inherent in a centralized approach, it
does introduce the capability for more
resiliency, local reliability, and local
energy independence.

IEEE Elec trific ation Magazine / d ec em be r 2 0 1 6

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