A Smart Grid Technology
A smart grid is a
modernized electrical grid that uses analogy or digital information
and communications technology to gather and act on information, such as
information about the behaviours of suppliers and consumers, in an automated
fashion to improve the efficiency, reliability, economics, and sustainability of
the production and distribution of electricity.
Roll-out of smart grid technology also implies
a fundamental re-engineering of the electricity services industry, although
typical usage of the term is focused on the technical infrastructure.
The Smart Grid
represents an unprecedented opportunity to move the energy industry into a new
era of reliability, availability, and efficiency that will contribute to
our economic and environmental health. During the transition period, it will be
critical to carry out testing, technology improvements, consumer education,
development of standards and regulations, and information sharing between
projects to ensure that the benefits we envision from the Smart Grid become a
reality. The benefits associated with the Smart Grid include:
- ·
More efficient transmission of electricity
- ·
Quicker restoration of electricity after power
disturbances
- ·
Reduced operations and management costs for
utilities, and ultimately lower power costs for consumers
- ·
Reduced peak demand, which will also help
lower electricity rates
·
Increased integration of large-scale renewable
energy systems
The Smart Grid will
consist of millions of pieces and parts—controls, computers, power lines, and
new technologies and equipment. It will take some time for all the technologies
to be perfected, equipment installed, and systems tested before it comes fully
on line. And it won’t happen all at once—the Smart Grid is evolving, piece by
piece, over the next decade or so. Once mature, the Smart Grid will likely
bring the same kind of transformation that the Internet has already brought to
the way we live, work, play, and learn.
The Smart Grid is not just
about utilities and technologies; it is about giving you the information and
tools you need to make choices about your energy use. If you already manage
activities such as personal banking from your home computer, imagine managing
your electricity in a similar way. A smarter grid will enable an unprecedented
level of consumer participation.
For example, you will no longer
have to wait for your monthly statement to know how much electricity you use.
With a smarter grid, you can have a clear and timely picture of it. "Smart
meters," and other mechanisms, will allow you to see how much electricity
you use, when you use it, and its cost. Combined with real-time
pricing, this will allow you to save money by using less power
when electricity is most expensive.
The Smart Home
How will the Smart Grid affect
your home? It won’t look very different, but behind the scenes a lot will be
happening. Even right now, in many cities across the nation, new equipment,
appliances, and software are available that use emerging Smart Grid
technologies to save energy, seek out the lowest rates, and contribute to the
smooth and efficient functioning of our electric grid.
Smart Meters and Home Energy
Management Systems
A key element that
allows all of the emerging Smart Grid technologies to function together is the
interactive relationship between the grid operators, utilities, and you.
Computerized controls in your home and appliances can be set up to respond to
signals from your energy provider to minimize their energy use at times when
the power grid is under stress from high demand, or even to shift some of
their power use to times when power is available at a lower cost.
Smart meters provide the Smart
Grid interface between you and your energy provider. Installed in place of your
old, mechanical meter, these meters operate digitally, and allow for automated
and complex transfers of information between your home and your energy
provider. For instance, smart meters will deliver signals from your energy
provider that can help you cut your energy costs. Smart meters also provide
utilities with greater information about how much electricity is being used
throughout their service areas.
This energy information coming to
and from your home through your smart meter can be run through a home energy
management system (EMS), which will allow you to view it in an
easy-to-understand format on your computer or hand-held device. A home EMS
allows you to track your energy use in detail to better save energy. For
instance, you can see the energy impact of various appliances and electronic
products simply by monitoring your EMS while switching the devices on and off.
An EMS also allows you to monitor
real-time information and price signals from your utility and create settings
to automatically use power when prices are lowest. You can also choose settings
that allow specific appliances and equipment to turn off automatically when a
large demand threatens to cause an outage—avoiding peak demand
rates, helping to balance the energy load in your area, and preventing
blackouts. Your utility may provide financial incentives for doing so.
Smart Appliances
In your smart home, many of your
appliances will be networked together, allowing you to access and operate them
through your EMS. An EMS provides the ability to turn on your heater or air
conditioner from work when you’re about to go home or keep track of the energy
use of specific appliances or equipment—like tracking the energy use of your
pool pump, or seeing how much energy you saved with your new Energy Star
dishwasher.
Smart appliances
will also be able to respond to signals from your energy provider to avoid
using energy during times of peak demand. This is more complicated than a
simple on and off switch. For instance, a smart air conditioner might extend
its cycle time slightly to reduce its load on the grid; while not
noticeable to you, millions of air conditioners acting the same way could
significantly reduce the load on the power grid. Likewise, a smart
refrigerator could defer its defrost cycle until off-peak hours, or a
smart dishwasher might defer running until off-peak hours.
Home Power generation
As consumers move toward home
energy generation systems, the interactive capacity of the Smart Grid will
become more and more important. Rooftop solar electric systems and small wind
turbines are now widely available, and people in rural areas may even consider
installing a small hydropower system on a nearby stream. Companies
are also starting to roll out home fuel cell systems, which produce heat and
power from natural gas.
The Smart Grid, with
its system of controls and smart meters, will help to effectively
connect all these mini-power generating systems to the grid, to provide data
about their operation to utilities and owners, and to know what surplus energy
is feeding back into the grid versus being used on site. A potential feature of
the Smart Grid will be to allow your community to use your solar array—and your
neighbor’s—to keep the lights on even when there is no power coming from a
utility. Called “islanding,” it will allow a home to grab power from
“distributed resources,” such as local rooftop solar, small hydropower, and
wind projects, until utility workers can bring the grid back online.
Renewable energy
Geography issues aside, the
current grid has difficulty accommodating variable sources of power like wind
and solar energy, the fastest-growing sources of renewable power on the grid.
As these resources begin to supply increasing percentages of power to the grid,
integrating them into grid operations will become increasingly difficult.
The Smart Grid will be able to
make better use of these energy resources. It will give grid operators new
tools to reduce power demand quickly when wind or solar power dips,
and it will have more energy storage capabilities to absorb excess wind and
solar power when it isn't needed, then to release that energy when the wind and
solar power dips. In effect, energy storage will help to smooth out the
variability in wind and solar resources, making them easier to use.
Building an electric superhighway
can also help solve the problem, as it will help to ship the power to where it
is needed. Studies have shown that connecting wind resources from a diversity
of geographic locations helps to balance out fluctuations in wind power. In other
words, when the wind isn't blowing in Iowa, in may be blowing in North Dakota
or Wyoming. Having such geographically diverse wind resources on a single
electric superhighway will result in a more steady supply of wind power to the
nation's power grid, making it easier for grid operators to make full use of
this resource.
Distribution intelligence
"Distribution
intelligence" refers to the part of the Smart Grid that applies to the
utility distribution system, that is, the wires, switches, and transformers
that connect the utility substation to you, the customers. The power lines that
run through people's back yards are one part of the power
distribution system.
A key component of distribution
intelligence is outage detection and response. Today, many utilities rely on
customer phone calls to know which areas of their
distribution system are being affected by a power outage. Along with
smart meters, distribution intelligence will help to quickly pinpoint the
source of a power outage so that repair crews can be immediately dispatched to
the problem area.
A utility's outage response can
also improve. Most utilities count on complex power distribution schemes and
manual switching to keep power flowing to most of their customers, even when
power lines are damaged and destroyed. However, this approach has its
limitations, and in many cases an automated system could respond more
quickly and could keep the power flowing to more customers.
By having sensors that can
indicate when parts of the distribution system have lost power, and
by combining automated switching with an intelligent system that
determines how best to respond to an outage, power can be rerouted to most
customers in a matter of seconds, or perhaps even milliseconds.
It may even be possible to react
quickly enough to power disturbances so that only those in the immediate
neighborhood are affected, while other customers' power source are rerouted
fast enough to avoid any interruption in power. This capability could be the
first example of the highly touted "self-healing" aspect of the Smart
Grid in action.
The "Self-Healing" Power Distribution System
Outage response is one aspect of
distribution intelligence that is commonly referred to as distribution
automation(DA). DA may actually be the oldest segment of the Smart Grid,
because utilities have been automating their distribution systems since the
1960s. But while DA initially focused just on remote control of switches, the
Electric Power Research Institute now considers distribution intelligence to
mean a fully controllable and flexible distribution system.
Combining DA components with a
set of intelligent sensors, processors, and communication technologies will
lead to distribution intelligence. When fully deployed, distribution
intelligence will enable an electric utility to remotely monitor and coordinate
its distribution assets, operating them in an optimal matter using either
manual or automatic controls.
Helping the Grid Run More Efficiently and Reliably
Along with outage detection and
response, another potential application of distribution intelligence is the
ability to optimize the balance between real and reactive power. Devices
that store and release energy, such as capacitors, or that use coils of wire to
induce magnetic fields, such as electrical motors, have the ability to cause
increased electrical currents without consuming real power; this is known
as reactive power.
A certain amount of reactive
power is desirable within a power system, but too much reactive
power can lead to large current flows that serve no purpose, causing
efficiency losses as they heat up the distribution system wires. An
intelligent distribution system can use power electronics to maintain
the proper level of reactive power in thesystem.
Distribution intelligence can
also help to protect and control the feeder lines, the power lines that make up
the distribution system. Most feeder lines are now protected by breakers
or relays that trip when high currents flow through the line, a situation
normally caused by a fault somewhere in the system. These relays
sometimes incorporate time delays to allow for momentary flows of high current,
which may be caused by industrial equipment powering up, rather than
a fault. Protection systems are often a combination of instantaneous
breakers with high current settings and time-delayed breakers or relays with
lower settings.
These systems of automated
breakers and relays end up being a balancing act: they must allow
the system to operate with high currents when needed but protect the system and
the people around it from high current flows when a fault exists.
Distribution intelligence can provide a more elegant approach to protecting the
feeder lines, using sophisticated monitoring and controls to detect and correct
for faults while maintaining the highest level ofsystem reliability during
non-fault conditions.
An
intelligent system could even detect and isolate faults in specific
pieces of equipment and route power through a backup system instead,
maintaining power reliability. Distribution intelligence can also incorporate
more sophisticated ground-fault detectors to minimize the possibility that
people can be shocked or electrocuted when encountering downed power lines.
Most utilities are only starting
on the road to true distribution intelligence, but the market is expected to
boom in the coming years.
Consumer Engagement
The Smart Grid offers many opportunities for consumers to
save energy and for utilities to operate the grid in a more efficient,
effective, and reliable way. But some features enabled by the Smart Grid also
involve some sacrifice on the part of consumers, such as holding off on running
your dishwasher until later in the evening.
A smart consumer will ask, "What's in it for me?"
And the answer is: money. Specifically, participating in these programs will
earn consumers extra savings on their energy bills. And for people who generate
their own power, it can even result in something you never thought you would
see: your utility could mail a check to you.
Many utilities already offer their customers ways to save
extra money on their utility bills. For people with central air conditioning
systems, for instance, some utilities will place a remote-control switch on the
air conditioner to cycle the air conditioner on and off during times of peak
power demand. In return, customers receive a credit on their electrical
bill.
The Smart Grid will allow programs like these to operate in
more sophisticated ways, resulting in greater energy savings with less
inconvenience to businesses and homeowners. Some examples
include time-of-use pricing, net metering, and compensation programs for
plug-in electric vehicles (PEVs)
