IEEE Power & Energy Magazine - January/February 2020 - 96

in my view

Eric Lightner

evolution of distribution
impacts on grid planning and operations

THE WORLDWIDE UTILITY INdustry has been changing for decades.
This is shown by the evolution of the
regulation of utilities, wholesale power
markets, and the relationship between
bulk power system operations and distribution system operations. Years ago,
distribution system owners passively
encouraged customer participation in
conservation programs but now have
become more actively engaged with
customers through a variety of offerings such as demand response. In addition, numerous sets of new technologies have been developed and used by
utilities for distribution system planning and management. In particular, the
application of information and communications technology has steadily
increased along with improvements in
sensing and measurement technology.
Through all the changes, the core utility customer-the end user of electric
power-was historically not impacted at
all. The consumers' expectations of their
source of energy did not change. The
consumer was still primarily the buyer of
electricity, and the regulated utility was
still primarily the seller. But that is changing, and with it comes new challenges to
the utility business model resulting from
the large-scale development of distributed
energy resources (DERs) and their use
in implementing non-wire alternatives
(NWAs) to physical system upgrades.
The types of DERs vary considerably.
For example, New York's Reforming the
Energy Vision (REV) initiative comprehensively defined DERs as a series
Digital Object Identifier 10.1109/MPE.2019.2949317
Date of current version: 7 January 2020

ieee power & energy magazine

of technologies that include renewable
energy resources, such as photovoltaics,
wind turbines, and hydropower; storage systems, including battery storage,
fuel cells, thermal storage, compressed
air, and flywheels; generation technologies, including biogas, cogeneration,
and combustion generators; and demand
response and energy efficiency.
Key characteristics of DERs are the
following:
✔ They are very often small and can
be installed almost anywhere with
very simple (or no) permitting
process.
✔ Many generate energy from renewable sources that are intermittent in nature and generally
cannot be dispatched.
✔ Some can store and deliver energy when needed.
✔ All of them are installed in the
distribution system or at customer sites.
Microgrids, which can be defined as
smaller grids within an existing distribution grid, are growing in number. These
microgrids can be self-sufficient in energy
supply and demand under some circumstances, which empowers the customer
and changes his or her relationship with
the electric utility. The utility and the customer now can be partners and collaborators in the planning and operation of distribution systems.

Transmission/Distribution
Planning or Delivery
System Planning
Utility planning focuses on solving
existing and future system problems.
Planned system improvements use ex-

isting mature technologies but sometimes apply novel, less mature, technologies that can be justified to regulatory
commissions as the most economical
solution to resolving system problems
with due consideration to customer
rates and acceptable levels of risk.
Globally, electric power utilities are
being encouraged to support decarbonization. This will result in the major
growth of DERs, which will greatly affect
distribution systems and ultimately transmission systems too. An example of an
international response to climate change
originates with the Paris Accord, including its Mission Innovation activity, Innovation Challenge 1: Smart Grids. Here,
countries internationally collaborate
on the development and deployment of
technologies supporting decarbonization of electric power systems. In the
United States, two major initiatives in
New York (REV) and California (Better
Than Smart) have identified major changes to their state's direction. Furthermore,
several states have already passed laws
indicating their plans to become carbon
free by 2040-2050. This means that over
the next 20 years, the supply of energy
will likely change from predominantly
centralized sources to predominantly
decentralized sources connected to the
distribution system, completely transforming the dynamics of maintaining the
reliability and resiliency of the network.
The transformation of the grid raises several questions:
✔ Does the demarcation between
transmission and distribution
make any sense?
(continued on p. 92)
january/february 2020

IEEE Power & Energy Magazine - January/February 2020

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