Baseload (also
base load, or
baseload demand) is the minimum amount of power that a utility or distribution company must make available to its customers, or the amount of power required to meet minimum demands based on reasonable expectations of customer requirements. Baseload values typically vary from hour to hour in most commercial and industrial areas.
Baseload plant, (also
baseload power plant or
base load power station) is an energy plant devoted to the production of baseload supply. Baseload plants are the production facilities used to meet some or all of a given region's continuous energy demand, and produce energy at a constant rate, usually at a low cost relative to other production facilities available to the system. Examples of baseload plants using nonrenewable fuels include
nuclearNuclear power is power produced from controlled nuclear reactions. Commercial plants in use to date use nuclear fission reactions....
and
coal-firedA fossil-fuel power plant is a power plant that burns fossil fuels such as coal, natural gas or petroleum to produce electricity.Fossil-fuel power plants are designed on a large scale for continuous operation...
plants. Among the renewable energy sources,
hydroelectricHydroelectricity is electricity generated by hydropower, i.e., the production of power through use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
,
geothermalGeothermal power is power extracted from heat stored in the earth. This geothermal energy originates from the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface...
and
OTECOcean thermal energy conversion is hydro energy conversion system which uses the temperature difference that exists between deep and shallow waters to run a heat engine. As with any heat engine, the greatest efficiency and power is produced with the largest temperature difference. This...
can provide baseload power. Baseload plants typically run at all times through the year except in the case of repairs or scheduled maintenance. (Hydroelectric power also has the desirable attribute of dispatchability, but a hydroelectric plant may run low on its fuel (water at the reservoir elevation) if a long
droughtA drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
occurs over its
drainage basinA drainage basin is an extent of land where water from rain or snow melt drains downhill into a body of water, such as a river, lake, reservoir, estuary, wetland, sea or ocean...
.)
Each baseload power plant on a grid is allotted a specific amount of the baseload power demand to handle. The base load power is determined by the
load duration curveA load duration curve is used in electric power generation to illustrate the relationship between generating capacity requirements and capacity utilization.A LDC is similar to a load curve but the demand data is ordered in descending...
of the system. For a typical power system, the
rule of thumbA rule of thumb is a principle with broad application that is not intended to be strictly accurate or reliable for every situation. It is an easily learned and easily applied procedure for approximately calculating or recalling some value, or for making some determination...
is that the base load power is usually 35-40% of the maximum load during the year.
Peaks or spikes in customer power demand are handled by smaller and more responsive types of power plants called
peaking power plantPeaking power plants, also known as peaker plants, are power plants that generally run only when there is a high demand, known as peak demand, for electricity....
s. In the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, peaking plants are typically powered with gas turbines.
Economics
Power plants are designated base load based on their low cost generation, efficiency and safety at set outputs. Baseload power plants do not change production to match power consumption demands since it is always cheaper to run them rather than running higher cost combined cycle plants or combustion turbines. Baseload generators, such as nuclear and coal, often have very large fixed costs and very low marginal costs. On the other hand, peak load generators, such as natural gas , have low fixed costs and high marginal costs. Typically these plants are large and provide a majority of the power used by a grid. Thus, they are more effective when used continuously to cover the power baseload required by the
gridElectric power transmission is the bulk transfer of electrical energy, a process in the delivery of electricity to consumers. A power transmission network typically connects power plants to multiple substations near a populated area...
.
Base load power plant usage
NuclearNuclear power is power produced from controlled nuclear reactions. Commercial plants in use to date use nuclear fission reactions....
and
coalA fossil-fuel power plant is a power plant that burns fossil fuels such as coal, natural gas or petroleum to produce electricity.Fossil-fuel power plants are designed on a large scale for continuous operation...
power plants may take many hours, if not days, to achieve a steady state power output. On the other hand, they have low
fuel costIn economics and finance, marginal cost is the change in total cost that arises when the quantity produced changes by one unit. It is the cost of producing one more unit of a good. Mathematically, the marginal cost function is expressed as the first derivative of the total cost function with...
s. Because they require a long period of time to heat up to operating temperature, these plants typically handle large amounts of baseload demand. Different plants and technologies may have differing capacities to increase or decrease output on demand: nuclear plants are generally run at close to peak output continuously (apart from maintenance,
refuelingNuclear fuel is any material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned to derive energy. By far the most common type of nuclear fuel is heavy fissile elements that can be made to undergo nuclear fission chain reactions in a nuclear fission reactor;...
and periodic refurbishment), while coal-fired plants may be cycled over the course of a day to meet demand. Plants with multiple generating units may be used as a group to improve the "fit" with demand, by operating each unit as close to peak
efficiencyEnergy conversion efficiency is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The useful output may be electric power, mechanical work, or heat. Energy conversion efficiency is not defined uniquely, but instead depends on the usefulness of the...
as possible.
See also
- Capacity factor
The net capacity factor of a power plant is the ratio of the actual output of a power plant over a period of time and its output if it had operated at full nameplate capacity the entire time. To calculate the capacity factor, total energy the plant produced during a period of time and divide by the...
- Energy demand management
Energy demand management, also known as demand side management , entails actions that influence the quantity or patterns of use of energy consumed by end users, such as actions targeting reduction of peak demand during periods when energy-supply systems are constrained...
- Grid energy storage
Grid energy storage refers to the methods used to store electrical energy within an electrical power grid. Electrical energy is stored during times when production exceeds consumption and the stores are utilized at times when consumption exceeds production...
- Intermittent power source
Intermittent energy source is a term usually used to refer to some sources of renewable energy, such as wind and solar,, because these sources of electric power generation may be uncontrollably variable or more intermittent than conventional power sources...
- Load balancing (electrical power)
Load balancing refers to the use of various techniques by electrical power stations to store excess electrical power during low demand periods for release as demand rises....
- Peaking power plant
Peaking power plants, also known as peaker plants, are power plants that generally run only when there is a high demand, known as peak demand, for electricity....
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