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Base-load
The base load (also baseload) is the minimum level of demand on an electrical grid over a span of time, for example, one week. This demand can be met by unvarying power plants, dispatchable generation, or by a collection of smaller intermittent energy sources, depending on which approach has the best mix of cost, availability and reliability in any particular market. The remainder of demand, varying throughout a day, is met by dispatchable generation which can be turned up or down quickly, such as load following power plants, peaking power plants, or energy storage. Power plants that do not change their power output quickly, such as large coal or nuclear plants, are generally called baseload power plants. Donald G. Fink, H. Wayne Beatty (ed), ''Standard Handbook for Electrical Engineers'', Eleventh Edition, Mc-Graw Hill, 1978 , pp. 12-16 through 12-18 Historically, most or all of base load demand was met with baseload power plants, whereas new capacity based around renewables ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Thermal Energy Conversion
Ocean Thermal Energy Conversion (OTEC) uses the ocean thermal gradient between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce useful work, usually in the form of electricity. OTEC can operate with a very high capacity factor and so can operate in base load mode. The denser cold water masses, formed by ocean surface water interaction with cold atmosphere in quite specific areas of the North Atlantic and the Southern Ocean, sink into the deep sea basins and spread in entire deep ocean by the thermohaline circulation. Upwelling of cold water from the deep ocean is replenished by the downwelling of cold surface sea water. Among ocean energy sources, OTEC is one of the continuously available renewable energy resources that could contribute to base-load power supply.Lewis, Anthony, et al. IPCC: Special Report on Renewable Energy Sources and Climate Change Mitigation, 2011 The resource potential for OTEC is considered to be much larger than for ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combined Cycle
A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. On land, when used to make electricity the most common type is called a combined cycle gas turbine (CCGT) plant. The same principle is also used for marine propulsion, where it is called a combined gas and steam (COGAS) plant. Combining two or more thermodynamic cycles improves overall efficiency, which reduces fuel costs. The principle is that after completing its cycle in the first engine, the working fluid (the exhaust) is still hot enough that a second subsequent heat engine can extract energy from the heat in the exhaust. Usually the heat passes through a heat exchanger so that the two engines can use different working fluids. By generating power from multiple streams of work, the overall efficiency can be increased by 50–60%. That is, from an overall efficiency of the system of say 34% for a simple cycle, to as much as 64% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispatchable Generation
Dispatchable generation refers to sources of electricity that can be programmed ''on demand'' at the request of power grid operators, according to market needs. Dispatchable generators may adjust their power output according to an order. Non-dispatchable renewable energy sources such as wind power and solar photovoltaic (PV) power cannot be controlled by operators. Other types of renewable energy that are dispatchable without separate energy storage are hydroelectric, biomass, geothermal and ocean thermal energy conversion. Startup time Dispatchable plants have varying startup times. The fastest plants to dispatch are grid batteries which can dispatch in milliseconds. Hydroelectric power plants can often dispatch in tens of seconds to minutes and natural gas power plants can generally dispatch in tens of minutes. For example, the 1,728 MW Dinorwig pumped storage power plant can reach full output in 16 seconds. Gas turbine (Brayton cycle) thermal plants require around 15 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermittent Energy Source
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or biomass, or relatively constant sources, such as geothermal power. The use of small amounts of intermittent power has little effect on grid operations. Using larger amounts of intermittent power may require upgrades or even a redesign of the grid infrastructure. Options to absorb large shares of variable energy into the grid include using storage, improved interconnection between different variable sources to smooth out supply, using dispatchable energy sources such as hydroelectricity and having overcapacity, so that sufficient energy is produced even when weather is less favourable. More connections between the energy sector and the building, transport and industrial sectors may also help. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peaking Power Plant
Peaking power plants, also known as peaker plants, and occasionally just "peakers", are power plants that generally run only when there is a high demand, known as peak demand, for electricity. Because they supply power only occasionally, the power supplied commands a much higher price per kilowatt hour than base load power. Peak load power plants are dispatched in combination with base load power plants, which supply a dependable and consistent amount of electricity, to meet the minimum demand. Although historically peaking power plants were frequently used in conjunction with coal baseload plants, peaking plants are now used less commonly. Combined cycle gas turbine plants have two or more cycles, the first of which is very similar to a peaking plant, with the second running on the waste heat of the first. That type of plant is often capable of rapidly starting up, albeit at reduced efficiency, and then over some hours transitioning to a more efficient baseload generation mode. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Power In France
Since the mid 1980s, the largest source of electricity in France is Nuclear power, with a generation of 379.5 TWh in 2019 and a total electricity production of . In 2018, the nuclear share was 71.67%, the highest percentage in the world. Since June 2020, it has 56 operable reactors totalling 61,370 MWe, one under construction (1630 MWe), and 14 shut down or in decommissioning (5,549 MWe). In May 2022, EDF reported that twelve reactors were shut down and being inspected for stress corrosion, requiring EDF to adjust its French nuclear output estimate for 2022 to 280-300 TWh; the estimate of the impact of the decrease in output on the Group's EBITDA for 2022 was assessed to be -€18,5 billion. Électricité de France (EDF)the country's main electricity generation and distribution company – manages the country's 56 power reactors. EDF is substantially owned by the French Government, with around 85% shares in government hands. "Shareholding policy". Électricité de France ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispatchable Generation
Dispatchable generation refers to sources of electricity that can be programmed ''on demand'' at the request of power grid operators, according to market needs. Dispatchable generators may adjust their power output according to an order. Non-dispatchable renewable energy sources such as wind power and solar photovoltaic (PV) power cannot be controlled by operators. Other types of renewable energy that are dispatchable without separate energy storage are hydroelectric, biomass, geothermal and ocean thermal energy conversion. Startup time Dispatchable plants have varying startup times. The fastest plants to dispatch are grid batteries which can dispatch in milliseconds. Hydroelectric power plants can often dispatch in tens of seconds to minutes and natural gas power plants can generally dispatch in tens of minutes. For example, the 1,728 MW Dinorwig pumped storage power plant can reach full output in 16 seconds. Gas turbine (Brayton cycle) thermal plants require around 15 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermittent Power Source
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or biomass, or relatively constant sources, such as geothermal power. The use of small amounts of intermittent power has little effect on grid operations. Using larger amounts of intermittent power may require upgrades or even a redesign of the grid infrastructure. Options to absorb large shares of variable energy into the grid include using storage, improved interconnection between different variable sources to smooth out supply, using dispatchable energy sources such as hydroelectricity and having overcapacity, so that sufficient energy is produced even when weather is less favourable. More connections between the energy sector and the building, transport and industrial sectors may also help. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blade Pitch
Blade pitch or simply pitch refers to the angle of a blade in a fluid. The term has applications in aeronautics, shipping, and other fields. Aeronautics In aeronautics, blade pitch refers to the angle of the blades of an aircraft propeller or helicopter rotor. Blade pitch is measured relative to the aircraft body. It is usually described as "fine" or "low" for a more vertical blade angle, and ,# "coarse" or "high" for a more horizontal blade angle. * i n Blade pitch is normally described as a ratio of forward distance per rotation assuming no slip. Blade pitch acts much like the gearing of the final drive of a car. Low pitch yields good low speed acceleration (and climb rate in an aircraft) while high pitch optimizes high speed performance and fuel economy. It is quite common for an aircraft to be designed with a variable-pitch * propeller, to give maximum thrust over a larger speed range. A fine pitch would be used during take-off and landing, whereas a coarser pitch is u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curtailment (electricity)
In electric grid power generators, curtailment is the deliberate reduction in output below what could have been produced in order to balance energy supply and demand or due to transmission constraints. The definition is not strict, and several types of curtailment exist. "Economic dispatch" (low market price) is the most common. Curtailment is a loss of potentially useful energy, and may impact power purchase agreements. However, utilizing all available energy may require costly methods such as building new power lines or storage, becoming more expensive than letting surplus power go unused. Examples After ERCOT built a new transmission line from the Competitive Renewable Energy Zone in West Texas to the central cities in the Texas Interconnection in 2013, curtailment was reduced from 8-16% to near zero.Wiser, Ryan H., and Mark Bolinger.2014 Wind Technologies Market Report page 38. ''Lawrence Berkeley National Laboratory'', August 2015. Curtailment of wind power in western China ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renewables Need Flexible Backup Not Baseload
Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation. Renewable energy often provides energy for electricity generation to a grid, air and water heating/cooling, and stand-alone power systems. Renewable energy technology projects are typically large-scale, but they are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. Renewable energy is often deployed together with further electrification, which has several benefits: electricity can move heat or objects efficiently, and is clean at the point of consumption. In addition, electrification with renewable energy is more efficient and therefore lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed Costs
In accounting and economics, 'fixed costs', also known as indirect costs or overhead costs, are business expenses that are not dependent on the level of goods or services produced by the business. They tend to be recurring, such as interest or rents being paid per month. These costs also tend to be capital costs. This is in contrast to variable costs, which are volume-related (and are paid per quantity produced) and unknown at the beginning of the accounting year. Fixed costs have an effect on the nature of certain variable costs. For example, a retailer must pay rent and utility bills irrespective of sales. As another example, for a bakery the monthly rent and phone line are fixed costs, irrespective of how much bread is produced and sold; on the other hand, the wages are variable costs, as more workers would need to be hired for the production to increase. For any factory, the fix cost should be all the money paid on capitals and land. Such fixed costs as buying machines and lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
