Showing posts with label Smart grid. Show all posts
Showing posts with label Smart grid. Show all posts

Thursday, 16 April 2015

Smart metering Technology for smart housing


A smart meter is usually an electronic device that records consumption of electric energy in intervals of an hour or less and communicates that information at least daily back to the utility for monitoring and billing.[7] Smart meters enable two-way communication between the meter and the central system. Unlike home energy monitors, smart meters can gather data for remote reporting. Such an advanced metering infrastructure (AMI) differs from traditional automatic meter reading (AMR) in that it enables two-way communications with the meter. Smart Meters are electronic measurement devices used by utilities to communicate information for billing customers and operating their electric systems. For over fifteen years electronic meters, have been used effectively by utilities in delivering accurate billing data for at least a portion of their customer base. Initially, the use of this technology was applied to commercial and industrial customers due to the need for more sophisticated rates and more granular billing data requirements. The use of electronic meters came into service to the largest customers of the utility and over time gradually expanded to all customer classes. This migration was made possible by decreasing cost of the technology and advanced billing requirements for all customer classes. The combination of the electronic meters with two-way communications technology for information, monitor, and control is commonly referred to as Advanced Metering infrastructure (AMI). Previous systems, which utilized one-way communications to collect meter data were referred to as AMR (Automated Meter Reading) Systems. AMI has developed over time, from its roots as a metering reading substitute (AMR) to today’s two-way communication and data system. Not until the Smart Grid initiatives were established were these meters and systems referred to as ―Smart Meters and Smart Meter Systems‖. Hence, the present state of these technologies should be more appropriately referred to as ―an evolution, not a revolution‖ because of the development and use of Smart Meter technology and communications over the last fifteen years. The combined technologies are also required to meet national standards for accuracy and operability essential in the industry. Utility Customers Better access and data to manage energy use More accurate and timely billing Improved and increased rate options Improved outage restoration Power quality data Customer Service & Field Operations Reduced cost of Metering reading Reduced trips for off-cycle reads Eliminates handheld meter reading equipment Reduced call center transactions Reduced collections and connects/disconnects Revenue Cycle Services - Billing, Accounting, Revenue Protection Reduced back office rebilling Early detection of meter tampering and theft Reduced estimated billing and billing errors Transmission and Distribution Improved transformer load management Improved capacitor bank switching Data for improved efficiency, reliability of service, losses, and loading Improved data for efficient grid system design Power quality data for the service areas Marketing & Load Forecasting Reduced costs for collecting load research data The Role of Utility Metering Operations Metering Services operations in utilities have traditionally been tasked with providing customer billing measurement and have been responsible for accuracy, precision, and robust operations of the meters and support devices. Using a national system of standards, formal quality processes, utility best practices, and a dedicated sense of purpose, utility metering professionals have strived to produce the best system for billing utility customers in the global electric industry. In joint partnership with meter and communications manufacturers, they have driven the development of electronic metering and metering communications to deliver the top notch Smart Metering Systems available in the marketplace today. For successful Smart Meter projects, Metering Services operations are an integral part of the project planning, deployment and maintenance of the systems. Their contributions in these areas of the process are required and fundamental to the project success. The most important contributions include: Development of the Business and Technical requirements of the Systems, Participant of the technology selection team, Certification of the system meters and devices, Acceptance of the incoming production products, Development of safe and appropriate installation plans and processes, Development of a maintenance model to support the new systems, Development of training programs , Design and implementation of an appropriate In-Service Testing & Compliance process With the significant increase of new measurement technologies and integration of communication systems into basic meters, metering operations will be challenged both technically and operationally in the near and long term. The emphasis on metering operations in utilities will increase as more sophisticated billing and measurement systems are developed, designed and deployed. The Smart Grid and Smart Meter Systems Smart Meter Systems are an integral part of the Smart Grid infrastructure in data collection and communications. The Smart Grid is essentially the modernization of the transmission and distribution aspects of the electrical grid. Functionally, it is an automated electric power system that monitors and controls grid activities, ensuring the efficient and reliable two-way flow of electricity and information between power plants and consumers—and all points in between. A Smart Grid monitors electricity delivery and tracks power consumption with smart meters that transmit energy usage information to utilities via communication networks. Smart meters also allow the customers to track their own energy use. Basic Types of Smart Meter Systems There are two basic categories of Smart Meter System technologies as defined by their LAN. They are Radio Frequency (RF) and Power Line Carrier (PLC). Each of these technologies has its own advantages and disadvantages in application. The utility selects the best technology to meet its demographic and business needs. Factors that impact the selection of the technology include evaluation of existing infrastructure; impact on legacy equipment, functionality, technical requirements as well has the economic impact to the utility’s customers. The selection of the technology requires a thorough evaluation and analysis of existing needs and future requirements into a single comprehensive business case. Radio Frequency – RF Smart Meter measurements and other data are transmitted by wireless radio from the meter to a collection point. The data is then delivered by various methods to the utility data systems for processing at a central location. The utility billing, outage management, and other systems use the data for operational purposes. RF technologies are usually two different types: Mesh Technology The smart meters talk to each other (hop) to form a LAN cloud to a collector. The collector transmits the data using various WAN methods to the utility central location. – Mesh RF Technologies’ advantages include acceptable latency, large bandwidth, and typically operate at 9157 MHz frequencies. – Mesh technologies disadvantages include terrain and distance challenges for rural areas, proprietary communications, and multiple collection points. Point to Point Technology The smart meters talk directly to a collector, usually a tower. The tower collector transmits the data using various methods to the utility central location for processing. – Point to Point RF technologies advantages include little or no latency, direct communication with each endpoint, large bandwidth for better throughput, some are licensed spectrum, and can cover longer distances. – The disadvantages of point to point RF networks are licensing (not for 900MHz), terrain may prove challenging in rural areas (Line of Sight), proprietary communications used for some technologies, and less interface with DA devices Power Line Carrier - PLC Smart Meter measurements and other data can be transmitted across the utility power lines from the meter to a collection point, usually in the distribution substation feeding the meter. Some solutions have the collection point located on the secondary side of a distribution transformer. The data is then delivered to the utility data systems for processing at a central location. The utility billing, outage management, and other systems use the data for operational purposes. PLC technology advantages include leveraging the use of existing utility infrastructure of poles & wires, improved cost effectiveness for rural lines, more effective in challenging terrain, and the capability to work over long distances. PLC disadvantages include longer data transmit time (more latency), less bandwidth and throughput, limited interface with Distribution Automation (DA) devices , and higher cost in urban and suburban locations. There are other Smart Meter Systems in use that differ from those described above. However, these are generally a hybrid or combination design, a slight variation of the basic types, or niche products. The major Smart Meter System Technologies in use today are of one of these basic types.

Thursday, 2 April 2015

Smart grid future grid for power distribution and monitoring


A smart grid is a modernized electrical grid that uses analog or digital information and communications technology to gather and act on information - such as information about the behaviors of suppliers and consumers - in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity. Electronic power conditioning and control of the production and distribution of electricity are important aspects of the smart grid. “Smart grid” generally refers to a class of technology people are using to bring utility electricity delivery systems into the 21st century, using computer-based remote control and automation. These systems are made possible by two-way communication technology and computer processing that has been used for decades in other industries. They are beginning to be used on electricity networks, from the power plants and wind farms all the way to the consumers of electricity in homes and businesses. They offer many benefits to utilities and consumers -- mostly seen in big improvements in energy efficiency on the electricity grid and in the energy users’ homes and offices. For a century, utility companies have had to send workers out to gather much of the data needed to provide electricity. The workers read meters, look for broken equipment and measure voltage, for example. Most of the devices utilities use to deliver electricity have yet to be automated and computerized. Now, many options and products are being made available to the electricity industry to modernize it. The “grid” amounts to the networks that carry electricity from the plants where it is generated to consumers. The grid includes wires, substations, transformers, switches and much more. Much in the way that a “smart” phone these days means a phone with a computer in it, smart grid means “computerizing” the electric utility grid. It includes adding two-way digital communication technology to devices associated with the grid. Each device on the network can be given sensors to gather data (power meters, voltage sensors, fault detectors, etc.), plus two-way digital communication between the device in the field and the utility’s network operations center. A key feature of the smart grid is automation technology that lets the utility adjust and control each individual device or millions of devices from a central location. Features of the smart grid The smart grid represents the full suite of current and proposed responses to the challenges of electricity supply. Because of the diverse range of factors there are numerous competing taxonomies and no agreement on a universal definition. Nevertheless, one possible categorisation is given here. Reliability The smart grid will make use of technologies, such as state estimation, that improve fault detection and allow self-healing of the network without the intervention of technicians. This will ensure more reliable supply of electricity, and reduced vulnerability to natural disasters or attack. Although multiple routes are touted as a feature of the smart grid, the old grid also featured multiple routes. Initial power lines in the grid were built using a radial model, later connectivity was guaranteed via multiple routes, referred to as a network structure. However, this created a new problem: if the current flow or related effects across the network exceed the limits of any particular network element, it could fail, and the current would be shunted to other network elements, which eventually may fail also, causing a domino effect. See power outage. A technique to prevent this is load shedding by rolling blackout or voltage reduction (brownout). The economic impact of improved grid reliability and resilience is the subject of a number of studies and can be calculated using a US DOE funded methodology for US locations using at least one calculation tool. Flexibility in network topology Next-generation transmission and distribution infrastructure will be better able to handle possible bidirection energy flows, allowing for distributed generation such as from photovoltaic panels on building roofs, but also the use of fuel cells, charging to/from the batteries of electric cars, wind turbines, pumped hydroelectric power, and other sources. Classic grids were designed for one-way flow of electricity, but if a local sub-network generates more power than it is consuming, the reverse flow can raise safety and reliability issues.[14] A smart grid aims to manage these situations.] Efficiency Numerous contributions to overall improvement of the efficiency of energy infrastructure are anticipated from the deployment of smart grid technology, in particular including demand-side management, for example turning off air conditioners during short-term spikes in electricity price, reducing the voltage when possible on distribution lines through Voltage/VAR Optimization (VVO), eliminating truck-rolls for meter reading, and reducing truck-rolls by improved outage management using data from Advanced Metering Infrastructure systems. The overall effect is less redundancy in transmission and distribution lines, and greater utilization of generators, leading to lower power prices. Load adjustment/Load balancing The total load connected to the power grid can vary significantly over time. Although the total load is the sum of many individual choices of the clients, the overall load is not a stable, slow varying, increment of the load if a popular television program starts and millions of televisions will draw current instantly. Traditionally, to respond to a rapid increase in power consumption, faster than the start-up time of a large generator, some spare generators are put on a dissipative standby mode. A smart grid may warn all individual television sets, or another larger customer, to reduce the load temporarily (to allow time to start up a larger generator) or continuously (in the case of limited resources). Using mathematical prediction algorithms it is possible to predict how many standby generators need to be used, to reach a certain failure rate. In the traditional grid, the failure rate can only be reduced at the cost of more standby generators. In a smart grid, the load reduction by even a small portion of the clients may eliminate the problem. Peak curtailment/leveling and time of use pricing To reduce demand during the high cost peak usage periods, communications and metering technologies inform smart devices in the home and business when energy demand is high and track how much electricity is used and when it is used. It also gives utility companies the ability to reduce consumption by communicating to devices directly in order to prevent system overloads. Examples would be a utility reducing the usage of a group of electric vehicle charging stations or shifting temperature set points of air conditioners in a city. To motivate them to cut back use and perform what is called peak curtailment or peak leveling, prices of electricity are increased during high demand periods, and decreased during low demand periods.[7] It is thought that consumers and businesses will tend to consume less during high demand periods if it is possible for consumers and consumer devices to be aware of the high price premium for using electricity at peak periods. This could mean making trade-offs such as cycling on/off air conditioners or running dishes at 9 pm instead of 5 pm. When businesses and consumers see a direct economic benefit of using energy at off-peak times, the theory is that they will include energy cost of operation into their consumer device and building construction decisions and hence become more energy efficient. According to proponents of smart grid plans, this will reduce the amount of spinning reserve that electric utilities have to keep on stand-by, as the load curve will level itself through a combination of "invisible hand" free-market capitalism and central control of a large number of devices by power management services that pay consumers a portion of the peak power saved by turning their device off.. Sustainability The improved flexibility of the smart grid permits greater penetration of highly variable renewable energy sources such as solar power and wind power, even without the addition of energy storage. Current network infrastructure is not built to allow for many distributed feed-in points, and typically even if some feed-in is allowed at the local (distribution) level, the transmission-level infrastructure cannot accommodate it. Rapid fluctuations in distributed generation, such as due to cloudy or gusty weather, present significant challenges to power engineers who need to ensure stable power levels through varying the output of the more controllable generators such as gas turbines and hydroelectric generators. Smart grid technology is a necessary condition for very large amounts of renewable electricity on the grid for this reason. Market-enabling The smart grid allows for systematic communication between suppliers (their energy price) and consumers (their willingness-to-pay), and permits both the suppliers and the consumers to be more flexible and sophisticated in their operational strategies. Only the critical loads will need to pay the peak energy prices, and consumers will be able to be more strategic in when they use energy. Generators with greater flexibility will be able to sell energy strategically for maximum profit, whereas inflexible generators such as base-load steam turbines and wind turbines will receive a varying tariff based on the level of demand and the status of the other generators currently operating. The overall effect is a signal that awards energy efficiency, and energy consumption that is sensitive to the time-varying limitations of the supply. At the domestic level, appliances with a degree of energy storage or thermal mass (such as refrigerators, heat banks, and heat pumps) will be well placed to 'play' the market and seek to minimise energy cost by adapting demand to the lower-cost energy support periods. This is an extension of the dual-tariff energy pricing mentioned above. Demand response support Demand response support allows generators and loads to interact in an automated fashion in real time, coordinating demand to flatten spikes. Eliminating the fraction of demand that occurs in these spikes eliminates the cost of adding reserve generators, cuts wear and tear and extends the life of equipment, and allows users to cut their energy bills by telling low priority devices to use energy only when it is cheapest. Currently, power grid systems have varying degrees of communication within control systems for their high value assets, such as in generating plants, transmission lines, substations and major energy users. In general information flows one way, from the users and the loads they control back to the utilities. The utilities attempt to meet the demand and succeed or fail to varying degrees (brownout, rolling blackout, uncontrolled blackout). The total amount of power demand by the users can have a very wide probability distribution which requires spare generating plants in standby mode to respond to the rapidly changing power usage. This one-way flow of information is expensive; the last 10% of generating capacity may be required as little as 1% of the time, and brownouts and outages can be costly to consumers. Latency of the data flow is a major concern, with some early smart meter architectures allowing actually as long as 24 hours delay in receiving the data, preventing any possible reaction by either supplying or demanding devices. Platform for advanced services As with other industries, use of robust two-way communications, advanced sensors, and distributed computing technology will improve the efficiency, reliability and safety of power delivery and use. It also opens up the potential for entirely new services or improvements on existing ones, such as fire monitoring and alarms that can shut off power, make phone calls to emergency services, etc. Provision megabits, control power with kilobits, sell the rest The amount of data required to perform monitoring and switching one's appliances off automatically is very small compared with that already reaching even remote homes to support voice, security, Internet and TV services. Many smart grid bandwidth upgrades are paid for by over-provisioning to also support consumer services, and subsidizing the communications with energy-related services or subsidizing the energy-related services, such as higher rates during peak hours, with communications. This is particularly true where governments run both sets of services as a public monopoly. Because power and communications companies are generally separate commercial enterprises in North America and Europe, it has required considerable government and large-vendor effort to encourage various enterprises to cooperate. Some, like Cisco, see opportunity in providing devices to consumers very similar to those they have long been providing to industry.[18] Others, such as Silver Spring Networks or Google, are data integrators rather than vendors of equipment. While the AC power control standards suggest powerline networking would be the primary means of communication among smart grid and home devices, the bits may not reach the home via Broadband over Power Lines (BPL) initially but by fixed wireless. The number of applications that can be used on the smart grid once the data communications technology is deployed is growing as fast as inventive companies can create and produce them. Benefits include enhanced cyber-security, handling sources of electricity like wind and solar power and even integrating electric vehicles onto the grid. The companies making smart grid technology or offering such services include technology giants, established communication firms and even brand new technology firms.