The power grid today:
The North American power grid has been described as the “supreme engineering achievement of the 20th century”. It is a vast electricity delivery infrastructure comprising transmission and distribution networks spanning the continental United States, connecting electricity generation to the consumers of electric power. The grid contains over 200,000 miles of high-voltage (over 230 kV) transmission lines and more than 6 million miles of distribution lines that deliver power to over 100 million customers and 283 million people.
However, the power grid today is aging, congested and increasingly seen as incapable of meeting the future energy needs of an Information Economy. As businesses have become dependent on electronic devices for information exchange and commerce, the use of electricity as an energy source has grown relative to fuels, currently representing 40% of overall energy consumption in the US. The importance of electricity as a driver of economic growth can be gauged from the fact that electricity sales trend with the growth of the GDP more closely than other energy sources, as shown in the following graphic. Assembled over the last century, the power grid was not designed to support the extensive coordination of generation, transmission and distribution that is called for today and it faces stresses and challenges that are creating drivers for the modernization and restructuring of the grid to accommodate the needs and requirements of a 21st century economy.
The North American power grid has been described as the “supreme engineering achievement of the 20th century”. It is a vast electricity delivery infrastructure comprising transmission and distribution networks spanning the continental United States, connecting electricity generation to the consumers of electric power. The grid contains over 200,000 miles of high-voltage (over 230 kV) transmission lines and more than 6 million miles of distribution lines that deliver power to over 100 million customers and 283 million people.
However, the power grid today is aging, congested and increasingly seen as incapable of meeting the future energy needs of an Information Economy. As businesses have become dependent on electronic devices for information exchange and commerce, the use of electricity as an energy source has grown relative to fuels, currently representing 40% of overall energy consumption in the US. The importance of electricity as a driver of economic growth can be gauged from the fact that electricity sales trend with the growth of the GDP more closely than other energy sources, as shown in the following graphic. Assembled over the last century, the power grid was not designed to support the extensive coordination of generation, transmission and distribution that is called for today and it faces stresses and challenges that are creating drivers for the modernization and restructuring of the grid to accommodate the needs and requirements of a 21st century economy.
Drivers for modernization of the power grid:
New challenges and drivers: The grid faces new challenges and stresses that will put at risk its ability to reliably deliver power to an economy that is increasingly dependent on electricity:
-- Growth in demand:
Peak demand is forecasted to grow by 18% over the next 10 years, driven by economic growth and the evolution towards an Information Economy. Electricity’s growing importance as a source of energy supply to the economy is reflected in the fact that over 40% of energy consumption in the US is used to produce electricity, up from 10% in 1940 and 25% in 1970.
-- Constraints on capacity expansion:
Simultaneously, generation capacity is forecasted to hit critical reserve limits within the next 10 years for most of the US and new transmission and generation projects are not expected to be completed in time to avoid hitting capacity issues.
-- Shifts in generation sources:
The shift towards newer renewable and distributed energy generation sources such as wind and solar that can be variable and located far from demand present new challenges of control and coordination for the power grid. Co-generation from non-traditional sources will be mandated in some places requiring two-way control and monitoring at non-utility owned facilities.
-- Transmission congestion:
Investments in the transmission infrastructure have not kept pace with the growth in demand, resulting in heavier utilization, frequent congestion, increased transmission losses and increased risk of catastrophic failures. Costs of building transmission lines and obtaining rights-of-way have increased dramatically and construction timelines will continue to increase.
-- Distribution:
Increased use of information technologies, computers and consumer electronics by customers has resulted in lowered tolerances to outages and power quality disturbances. A growing interest in distributed generation and electric storage devices at the edge is adding new requirements for interconnection and safe operation of electric distribution systems. Emerging trends such as plug-in hybrid electric vehicles (PHEVs) promise to put still more stress on the already-strained generation, transmission and distribution systems.
-- Demand management:
Utilities see an increasing need for demand management as a way to improve operating costs, enhance reliability and to potentially defer construction of generation and transmission capacity. The need to regulate and control the demand side through demand response and time-based rates — both of which require two-way communications capabilities down to the individual meter — adds another layer of complexity to the grid.
-- Regulatory policy:
Federal governments and many states are passing energy efficiency mandates and PUCs are enabling utilities to recover investments in upgrading the grid infrastructure and implementing measures such as demand response.
-- Environmental impact:
Electric power generation accounts for approximately 25% of the world’s carbon dioxide emissions and new carbon regulations will have a major impact on the industry. Building new transmission lines will encounter stricter environmental impact requirements than ever before.
The vision of a smart grid:
A growing recognition of the need to modernize the grid to meet tomorrow’s challenges has found articulation in the vision of a smart grid. Multiple industry and research groups have created architectural blueprints for the evolution of today’s power grid into a smart grid that share several common features.
The smart grid, as it is conceived today, will offer several benefits to utilities and consumers:
Simultaneously, generation capacity is forecasted to hit critical reserve limits within the next 10 years for most of the US and new transmission and generation projects are not expected to be completed in time to avoid hitting capacity issues.
-- Shifts in generation sources:
The shift towards newer renewable and distributed energy generation sources such as wind and solar that can be variable and located far from demand present new challenges of control and coordination for the power grid. Co-generation from non-traditional sources will be mandated in some places requiring two-way control and monitoring at non-utility owned facilities.
-- Transmission congestion:
Investments in the transmission infrastructure have not kept pace with the growth in demand, resulting in heavier utilization, frequent congestion, increased transmission losses and increased risk of catastrophic failures. Costs of building transmission lines and obtaining rights-of-way have increased dramatically and construction timelines will continue to increase.
-- Distribution:
Increased use of information technologies, computers and consumer electronics by customers has resulted in lowered tolerances to outages and power quality disturbances. A growing interest in distributed generation and electric storage devices at the edge is adding new requirements for interconnection and safe operation of electric distribution systems. Emerging trends such as plug-in hybrid electric vehicles (PHEVs) promise to put still more stress on the already-strained generation, transmission and distribution systems.
-- Demand management:
Utilities see an increasing need for demand management as a way to improve operating costs, enhance reliability and to potentially defer construction of generation and transmission capacity. The need to regulate and control the demand side through demand response and time-based rates — both of which require two-way communications capabilities down to the individual meter — adds another layer of complexity to the grid.
-- Regulatory policy:
Federal governments and many states are passing energy efficiency mandates and PUCs are enabling utilities to recover investments in upgrading the grid infrastructure and implementing measures such as demand response.
-- Environmental impact:
Electric power generation accounts for approximately 25% of the world’s carbon dioxide emissions and new carbon regulations will have a major impact on the industry. Building new transmission lines will encounter stricter environmental impact requirements than ever before.
The vision of a smart grid:
A growing recognition of the need to modernize the grid to meet tomorrow’s challenges has found articulation in the vision of a smart grid. Multiple industry and research groups have created architectural blueprints for the evolution of today’s power grid into a smart grid that share several common features.
The smart grid, as it is conceived today, will offer several benefits to utilities and consumers:
—It will provide utilities the ability to monitor and manage their power delivery down to the home or business in real time
—Utilities can offer multiple rate structures to manage demand peaks and offer demand management services to encourage efficiency
—It will allow utilities to manage outages more effectively by reducing their occurrence through better monitoring and control of the grid and by reducing the impact of outages through more efficient and early problem isolation, using techniques such as automatic load-shedding and islanding as well as faster recovery procedures. Power outages are estimated to impose an economic cost of upwards of $100 billion every year and, in an increasingly interconnected Information Economy, it is imperative to reduce the frequency and the impacts of outages as well as of disturbances in power quality.
—It will allow utilities to delay the construction of new plants and transmission lines and better manage their carbon output through implementing measures such as demand response and time-based rates to more actively manage load.
—It will allow utilities to provide real-time information to their customers and to utility workers in the field, resulting in operational efficiencies and more reliable service.
—It will allow utilities to more proactively manage the integration of clean energy technologies into the grid to maximize their environmental benefits and operational value.
The smart grid is envisioned to offer these benefits by enabling and enhancing a broad range of utility applications, including Advanced Metering Infrastructure (AMI), outage management, demand management, distribution automation, substation security and mobile workforce connectivity.
From a technological perspective, the essence of the smart grid vision is “the digital control of the power delivery network and two-way communication with customers and market participants” through the realization of “a fully-automated power delivery network that can ensure a two-way flow of electricity and information between the power plants and appliances and all points in between.”9 The central idea behind the smart grid vision is that information technology can revolutionize the generation and delivery of electricity just as it has transformed other aspects of business. It is an ambitious but attainable vision that comprises distributed intelligence, broadband communications and automated control systems – building on commercially-proven technologies that exist today.
-- Distributed intelligence:
This builds on advanced sensors with processing and communications capabilities built into every element of the grid (switches, transformers, substations, distribution lines, etc.) as well as advanced metering endpoints and smart appliances in the home. The distributed intelligence will enable real-time monitoring, coordination and control. For example, advanced meters with wide-area wireless communications capabilities can report back interval data to a meter data management system several times a day, allowing for real-time demand response coordination. Advanced sensors can be used to monitor the health of the grid in real-time and respond (perhaps autonomously, without central coordination) to avert system-wide failures and outages.
--Broadband communications:
A broadband communications infrastructure is key to enabling comprehensive system-wide monitoring and coordination to enable applications as diverse as distribution automation, demand response, outage management and power quality monitoring. These applications include requirements for low latency, high bandwidth and QoS prioritization that require a broadband network. The communications infrastructure would tie together the meter end-points, the utility mobile workforce, advanced sensors and control centers into a single integrated network. SCADA systems employed today do not sense or control nearly enough of the components of the grid and there is a need for reliable, up-to-date information to feed state estimation, contingency analysis and other procedures. Furthermore, the communications links in use today are proprietary (non-standard) and slow (high latency, low capacity). However, standards-based technologies exist today to enable multiple low-latency high-data-rate, two-way communications links among all the nodes in the network, extending from the control centers down to the substations and all the way down to individual meters.
--Automated control systems:
The third major element consists of centralized software tools and algorithms for self-re configuring and adapting the grid, executing protocols for demand response and automatic load-shedding, and promoting better coordination within and between utilities.
—Utilities can offer multiple rate structures to manage demand peaks and offer demand management services to encourage efficiency
—It will allow utilities to manage outages more effectively by reducing their occurrence through better monitoring and control of the grid and by reducing the impact of outages through more efficient and early problem isolation, using techniques such as automatic load-shedding and islanding as well as faster recovery procedures. Power outages are estimated to impose an economic cost of upwards of $100 billion every year and, in an increasingly interconnected Information Economy, it is imperative to reduce the frequency and the impacts of outages as well as of disturbances in power quality.
—It will allow utilities to delay the construction of new plants and transmission lines and better manage their carbon output through implementing measures such as demand response and time-based rates to more actively manage load.
—It will allow utilities to provide real-time information to their customers and to utility workers in the field, resulting in operational efficiencies and more reliable service.
—It will allow utilities to more proactively manage the integration of clean energy technologies into the grid to maximize their environmental benefits and operational value.
The smart grid is envisioned to offer these benefits by enabling and enhancing a broad range of utility applications, including Advanced Metering Infrastructure (AMI), outage management, demand management, distribution automation, substation security and mobile workforce connectivity.
From a technological perspective, the essence of the smart grid vision is “the digital control of the power delivery network and two-way communication with customers and market participants” through the realization of “a fully-automated power delivery network that can ensure a two-way flow of electricity and information between the power plants and appliances and all points in between.”9 The central idea behind the smart grid vision is that information technology can revolutionize the generation and delivery of electricity just as it has transformed other aspects of business. It is an ambitious but attainable vision that comprises distributed intelligence, broadband communications and automated control systems – building on commercially-proven technologies that exist today.
-- Distributed intelligence:
This builds on advanced sensors with processing and communications capabilities built into every element of the grid (switches, transformers, substations, distribution lines, etc.) as well as advanced metering endpoints and smart appliances in the home. The distributed intelligence will enable real-time monitoring, coordination and control. For example, advanced meters with wide-area wireless communications capabilities can report back interval data to a meter data management system several times a day, allowing for real-time demand response coordination. Advanced sensors can be used to monitor the health of the grid in real-time and respond (perhaps autonomously, without central coordination) to avert system-wide failures and outages.
--Broadband communications:
A broadband communications infrastructure is key to enabling comprehensive system-wide monitoring and coordination to enable applications as diverse as distribution automation, demand response, outage management and power quality monitoring. These applications include requirements for low latency, high bandwidth and QoS prioritization that require a broadband network. The communications infrastructure would tie together the meter end-points, the utility mobile workforce, advanced sensors and control centers into a single integrated network. SCADA systems employed today do not sense or control nearly enough of the components of the grid and there is a need for reliable, up-to-date information to feed state estimation, contingency analysis and other procedures. Furthermore, the communications links in use today are proprietary (non-standard) and slow (high latency, low capacity). However, standards-based technologies exist today to enable multiple low-latency high-data-rate, two-way communications links among all the nodes in the network, extending from the control centers down to the substations and all the way down to individual meters.
--Automated control systems:
The third major element consists of centralized software tools and algorithms for self-re configuring and adapting the grid, executing protocols for demand response and automatic load-shedding, and promoting better coordination within and between utilities.
No comments:
Post a Comment