POWER SYSTEMS

GENERATION

TRANSMISSION

DISTRIBUTION

COMPONENTS

SMART GRID

HISTORY

FUN ZONE

Definition of "smart grid"
United States: The first official definition of Smart Grid was provided by the Energy Independence and Security Act of 2007 (EISA-2007), which was approved by the US Congress in January 2007. Title XIII of this bill provides a description, with ten characteristics, that can be considered a definition for Smart Grid, as follows: "It is the policy of the United States to support the modernization of the Nation's electricity transmission and distribution system to maintain a reliable and secure electricity infrastructure that can meet future demand growth and to achieve each of the following, which together characterize a Smart Grid:
(1) Increased use of digital information and controls technology to improve reliability, security, and efficiency of the electric grid.
(2) Dynamic optimization of grid operations and resources, with full cyber-security.
(3) Deployment and integration of distributed resources and generation, including renewable resources.
(4) Development and incorporation of demand response, demand-side resources, and energy-efficiency resources.
(5) Deployment of 'smart' technologies (real-time, automated, interactive technologies that optimize the physical operation of appliances and consumer devices) for metering, communications concerning grid operations and status, and distribution automation.
(6) Integration of 'smart' appliances and consumer devices.
(7) Deployment and integration of advanced electricity storage and peak-shaving technologies, including plug-in electric and hybrid electric vehicles, and thermal storage air conditioning.
(8) Provision to consumers of timely information and control options.
(9) Development of standards for communication and interoperability of appliances and equipment connected to the electric grid, including the infrastructure serving the grid.
(10) Identification and lowering of unreasonable or unnecessary barriers to adoption of smart grid technologies, practices, and services."

European Union: The European Union Commission Task Force for Smart Grids also provides smart grid definition as: "A Smart Grid is an electricity network that can cost efficiently integrate the behaviour and actions of all users connected to it – generators, consumers and those that do both – in order to ensure economically efficient, sustainable power system with low losses and high levels of quality and security of supply and safety. A smart grid employs innovative products and services together with intelligent monitoring, control, communication, and self-healing technologies in order to:
* Better facilitate the connection and operation of generators of all sizes and technologies.
* Allow consumers to play a part in optimising the operation of the system. Provide consumers with greater information and options for how they use their supply.
* Significantly reduce the environmental impact of the whole electricity supply system.
* Maintain or even improve the existing high levels of system reliability, quality and security of supply.
* Maintain and improve the existing services efficiently."

What Makes a Grid “Smart?”
In short, the digital technology that allows for two-way communication between the utility and its customers, and the sensing along the transmission lines is what makes the grid smart. Like the Internet, the Smart Grid will consist of controls, computers, automation, and new technologies and equipment working together, but in this case, these technologies will work with the electrical grid to respond digitally to our quickly changing electric demand.

What does a Smart Grid do?
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
* Better integration of customer-owner power generation systems, including renewable energy systems * Improved security

Today, an electricity disruption such as a blackout can have a domino effect—a series of failures that can affect banking, communications, traffic, and security. This is a particular threat in the winter, when homeowners can be left without heat. A smarter grid will add resiliency to our electric power System and make it better prepared to address emergencies such as severe storms, earthquakes, large solar flares, and terrorist attacks. Because of its two-way interactive capacity, the Smart Grid will allow for automatic rerouting when equipment fails or outages occur. This will minimize outages and minimize the effects when they do happen. When a power outage occurs, Smart Grid technologies will detect and isolate the outages, containing them before they become large-scale blackouts. The new technologies will also help ensure that electricity recovery resumes quickly and strategically after an emergency—routing electricity to emergency services first, for example. In addition, the Smart Grid will take greater advantage of customer-owned power generators to produce power when it is not available from utilities. By combining these "distributed generation" resources, a community could keep its health center, police department, traffic lights, phone System, and grocery store operating during emergencies. In addition, the Smart Grid is a way to address an aging energy infrastructure that needs to be upgraded or replaced. It’s a way to address energy efficiency, to bring increased awareness to consumers about the connection between electricity use and the environment. And it’s a way to bring increased national security to our energy System—drawing on greater amounts of home-grown electricity that is more resistant to natural disasters and attack.

Giving Consumers Control
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. While the potential benefits of the Smart Grid are usually discussed in terms of economics, national security, and renewable energy goals, the Smart Grid has the potential to help you save money by helping you to manage your electricity use and choose the best times to purchase electricity. And you can save even more by generating your own power.

Grid Operation Centers
Today's electrical transmission System—including the giant power lines and transmission towers that snake across our landscapes—operates much like a System of interconnected streams. Power flows through the transmission System along the path of least resistance, finding multiple paths between the power plants and the cities that are demanding the power. Grid operators actually have very little control over today's System. Their primary task is to make sure that as much power is being generated as is being used—if not, the grid's voltage could drop, causing the grid to become unstable. Operators generally know which lines are in service and when relays have opened to protect lines against faults, but they have limited control capabilities. Unfortunately, like water in a bathtub, power can "slosh around" within the grid, developing oscillations that, under the worst of conditions, could lead to widespread blackouts. To compound the problem, grid operators also have limited information about how the power is flowing through the grid. The Smart Grid will help solve this problem by adding new capabilities for measurement and control of the transmission System. These technologies will make the grid much more reliable and will minimize the possibility of widespread blackouts.

The Smart Grid Solution
Smart Grid technologies offer a new solution to the problem of monitoring and controlling the grid's transmission System. New technologies called Phasor Measurement Units (PMU) sample voltage and current many times per second at a given location, providing a snapshot of the power System at work. PMUs provide a new monitoring tool for the Smart Grid. In our current electric grid, measurements are taken once every 2 or 4 seconds, offering a steady-state view into the power System behavior. Equipped with Smart Grid communications technologies, measurements can be taken many times a second, offering dynamic visibility into the power System. This makes it easier to detect the types of oscillations that led to the 2003 blackout.

The "Self-Healing" Grid
Smart Grid technologies also offer new means of controlling the transmission System. New high-power electronics function essentially as large-scale versions of transistors, adding a new level of control to the transmission System. New technologies could also help dampen unwanted power oscillations and avoid unproductive flows of current through the grid that only serve to waste energy. The combination of new measurement and control technologies also enables a new automated approach to controlling the grid. Software could potentially monitor the grid in real time for potential disturbances that could lead to blackouts, and it could take actions to check the disturbances. Such monitoring software could act to dampen out oscillations in the power grid, or it could even reroute power through the grid to avoid overloading a transmission line. In the event that a power line needs to be removed from service, control software could reroute the power in a way that causes minimal disruptions to the grid. This approach is often referred to as the "self-healing" grid. The ideal self-healing grid will involve a combination of transmission System monitoring and control software and comparable measures for the local distribution systems that deliver the power to individual homes and businesses. These distribution System measures are sometimes referred to as distribution intelligence.

“Seeing” the Smart Grid
Another contributor to the 2003 blackout was the limited situational awareness of the various grid operators involved. At the time, there was limited data sharing and transparency among the grid operators in different regions of North America, making it hard for the individual grid operators to see the big picture. By including new standards that make it easier for grid systems to interact with one another, the Smart Grid will make data sharing among regional grid operators easier to accomplish. Potentially, grid operators will be able to explore the state of the grid at the national level and switch within seconds to explore specific details at the local level. These technologies will provide rapid information about blackouts and power quality as well as insights into System operations for utilities.

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 the System. 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 of System 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.