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Load Profile
In electrical engineering, a load profile is a graph of the variation in the electrical load versus time. A load profile will vary according to customer type (typical examples include residential, commercial and industrial), temperature and holiday seasons. Power producers use this information to plan how much electricity they will need to make available at any given time. Teletraffic engineering uses a similar load curve. Power generation In a power system, a load curve or load profile is a chart illustrating the variation in demand/electrical load over a specific time. Generation companies use this information to plan how much power they will need to generate at any given time. A load duration curve is similar to a load curve. The information is the same but is presented in a different form. These curves are useful in the selection of generator units for supplying electricity. Electricity distribution In an electricity distribution grid, the load profile of electricity u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Forward Agreement
Electricity Forward Agreement (calendar) (short: EFA system) is a calendar used to specify load profiles when trading on the electricity market. It was officially only valid until October 2014, but is still abundantly used among commodity traders. Features of the EFA calendar One distinguishes between weekdays ''WD'' and weekend ''WE'' since the electricity consumption is clearly lower on Saturdays and Sundays. An ''EFA day'' starts on 11pm local time and runs through to 11pm the next (astronomical) day. An EFA-week ''WK'' consists of five ''WD'' and two ''WE''-days. An ''EFA month'' is defined differently to common months: March, June, September and December have five weeks, all other months are considered to have exactly four weeks. The two ''EFA seasons'' are winter (WK 40 – WK 13) and summer (WK 14 – WK 39), each having exactly 26 weeks. Due to the existence of leap years, some EFA-Decembers have six weeks (e.g. 2004 and 2009), a strong difference from the commonly used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vehicle-to-grid
Vehicle-to-grid (V2G), also known as Vehicle-to-home (V2H) or Vehicle-to-load (V2L) describes a system in which plug-in electric vehicles (PEV) sell demand response services to the grid. Demand services are either delivering electricity or by reducing their charging rate. Demand services reduce pressure on the grid, which might otherwise experience disruption from load variations. Plug-in electric vehicles include battery electric vehicles (BEV), plug-in hybrids (PHEV), and hydrogen vehicles. They share the ability to generate electricity. That electricity is typically used to power the vehicle. However, at any given time 95% of cars are parked, while their energy sits unused. V2G envisions sending some of the stored power to the grid (or reducing charge rates to pull less power from the grid). A 2015 report found that vehicle owners could receive significant payments. Batteries have a finite number of charging cycles, as well as a shelf-life, therefore V2G can impact battery lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peak Demand
Peak demand on an electrical grid is simply the highest electrical power demand that has occurred over a specified time period (Gönen 2008). Peak demand is typically characterized as annual, daily or seasonal and has the unit of power. Peak demand, peak load or on-peak are terms used in energy demand management describing a period in which electrical power is expected to be provided for a sustained period at a significantly higher than average supply level. Peak demand fluctuations may occur on daily, monthly, seasonal and yearly cycles. For an electric utility company, the actual point of peak demand is a single half-hour or hourly period which represents the highest point of customer consumption of electricity. At this time there is a combination of office, domestic demand and at some times of the year, the fall of darkness. Some utilities will charge customers based on their individual peak demand. The highest demand during each month or even a single 15 to 30 minute period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Distribution
Electric power distribution is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between and with the use of transformers. ''Primary'' distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment and household appliances. Often several customers are supplied from one transformer through ''secondary'' distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level. The transition from transmission to distribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid. Efficient long-distance transmission of electric power requires high voltages. This reduces the losses produced by strong currents. Transmission lines use either alternating current (HVAC) or direct current (HVDC). The voltage level is changed with transformers. The voltage is stepped up for transmission, then reduced for local distribution. A wide area synchronous grid, known as an "interconnection" in North America, directly connects generators delivering AC power with the same rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Generation
Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transmission, transmission, Electric power distribution, distribution, etc.) to end users or its Grid energy storage, storage (using, for example, the Pumped-storage hydroelectricity, pumped-storage method). Electricity is not freely available in nature, so it must be "produced" (that is, transforming other forms of energy to electricity). Production is carried out in power stations (also called "power plants"). Electricity is most often generated at a power plant by electromechanical electric generator, generators, primarily driven by heat engines fueled by combustion or nuclear fission but also by other means such as the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaics and geothermal power. There are al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duck Curve
The duck curve is a graph of power production over the course of a day that shows the timing imbalance between peak demand and renewable energy production. Used in utility-scale electricity generation, the term was coined in 2012 by the California Independent System Operator. Solar power In some energy markets, daily peak demand occurs after sunset, when solar power is no longer available. In locations where a substantial amount of solar electric capacity has been installed, the amount of power that must be generated from sources other than solar or wind displays a rapid increase around sunset and peaks in the mid-evening hours, producing a graph that resembles the silhouette of a duck.Paul Denholm, Matthew O'Connell, Gregory Brinkman, and Jennie Jorgenson.Overgeneration from Solar Energy in California: A Field Guide to the Duck Chart NREL/TP-6A20-65023. ''National Renewable Energy Laboratory'', November 2015 In Hawaii, significant adoption of solar generation has led to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cost Of Electricity By Source
Different methods of electricity generation can incur a variety of different costs, which can be divided into three general categories: 1) wholesale costs, or all costs paid by utilities associated with acquiring and distributing electricity to consumers, 2) retail costs paid by consumers, and 3) external costs, or externalities, imposed on society. Wholesale costs include initial capital, operations & maintenance (O&M), transmission, and costs of decommissioning. Depending on the local regulatory environment, some or all wholesale costs may be passed through to consumers. These are costs per unit of energy, typically represented as dollars/megawatt hour (wholesale). The calculations also assist governments in making decisions regarding energy policy. On average the levelized cost of electricity from utility scale solar power and onshore wind power is less than from coal and gas-fired power stations, but this varies a lot depending on location. Cost metrics Levelized cost o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smart Meter
A smart meter is an electronic device that records information such as consumption of electric energy, voltage levels, current, and power factor. Smart meters communicate the information to the consumer for greater clarity of consumption behavior, and electricity suppliers for system monitoring and customer billing. Smart meters typically record energy near real-time, and report regularly, short intervals throughout the day. Smart meters enable two-way communication between the meter and the central system. Such an advanced metering infrastructure (AMI) differs from automatic meter reading (AMR) in that it enables two-way communication between the meter and the supplier. Communications from the meter to the network may be wireless, or via fixed wired connections such as power line carrier (PLC). Wireless communication options in common use include cellular communications, Wi-Fi (readily available), wireless ad hoc networks over Wi-Fi, wireless mesh networks, low power long- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smart Grid
A smart grid is an electrical grid which includes a variety of operation and energy measures including: *Advanced metering infrastructure (of which smart meters are a generic name for any utility side device even if it is more capable e.g. a fiber optic router) *Smart distribution boards and circuit breakers integrated with home control and demand response (''behind the meter'' from a utility perspective) **Load control switches and smart appliances, often financed by efficiency gains on municipal programs (e.g. PACE financing) *Renewable energy resources, including the capacity to charge parked (electric vehicle) batteries or larger arrays of batteries recycled from these, or other energy storage. *Energy efficient resources *Sufficient utility grade fiber broadband to connect and monitor the above, with wireless as a backup. Sufficient spare if "dark" capacity to ensure failover, often leased for revenue. Electronic power conditioning and control of the production and distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
