IEEE Electrification Magazine - March 2014 - 12

By Peter Asmus

Why Microgrids
Are Moving into
the Mainstream
Improving the efficiency of the larger power grid.

he U.S. Utility grid waS graded a
lowly d+ by the american Council of Civil
engineers in 2009. although that was five
years ago, the performance of the U.S. grid
has actually declined since that grade was
issued. the galvin electricity initiative estimates that the
present antiquated dumb electric grid costs U.S. consumers US$140 billion annually because of power outages.
this declining quality of power service in the United
States is contributing to a flood of interest in the concept
of microgrids. these modular low- to medium-voltage
distribution level networks can (theoretically) provide
24/7 energy services regardless of the status of any larger
utility grid network. at the same time, microgrids can
reduce carbon emissions regionally and improve the
overall efficiency of the larger power grid-if they are
authorized to do so by regulators and utilities. it is this
latter possibility of providing ancillary services to the
larger grid that is allowing microgrids to inch their way
into the mainstream, sparking debate within the corporate suites of utility executives as well as within the circles of utility engineers.
No doubt, the future development of the U.S. grid will
require the safe and economic operation of the high-voltage meshed transmission grid since it is a US$800 billion

Digital Object Identifier 10.1109/MELE.2013.2297021
Date of publication: 18 March 2014

I E E E E l e c t r i f i cati o n M agaz ine / MARCH 2014

asset that is fully amortized. yet, the fundamental architecture of today's electricity grid, which is based on the
idea of a top-down radial transmission system predicated
on unidirectional energy flows from large centralized
power plants, is increasingly becoming obsolete. the economies of scale that once favored such monopoly models
no longer hold as markets now favor distributed and
decentralized devices whose energy services are more
customized and based on local availability and timing.
Perhaps the most glaring statistic gleaned from the
U.S. energy information administration is this: for every
1 Mw of power consumed by U.S. commercial and residential customers, rate payers are paying for 2.2 Mw of
generation and transmission capacity. that means that
we are building twice as much wholesale supply capacity as what is ideally needed. if instead, the utility power
grid took advantage of new smart grid technologies as
well as growing innovation on the financial side in the
form of new transactive energy service business models, these numbers would look very different. One
answer to this inefficiency is networks of distributed
energy resources providing a greater share of local
needs, shrinking line losses associated with centralized
power plants, and building greater resiliency into the
overall system. in short, a greater reliance upon
microgrids to aggregate and optimize distributed energy
resources (ders).
a clear definition of what is and what is not a
microgrid is still open to debate. do microgrids need to
2325-5987/14/$31.00©2014IEEE

Table of Contents for the Digital Edition of IEEE Electrification Magazine - March 2014