Base load power plant
Encyclopedia
Baseload 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.
and coal-fired
plants. Among the renewable energy sources, hydroelectric
, geothermal
, biogas
, biomass
, solar thermal with storage and ocean thermal energy conversion
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 drought
occurs over its drainage basin
.
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 curve
of the system. For a typical power system, the rule of thumb 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 plant
s, typically powered with gas turbines.
Whilst historically large power grids have had base load power plant to exclusively meet the base load, there is no specific technical requirement for this to be so. The baseload can equally well be met by the appropriate quantity of intermittent power source
s and peaking power plant.
, have low fixed costs, low plant load factor and high marginal costs. Typically baseload 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 grid.
and coal
power plants may take many hours, if not days, to achieve a steady state power output. On the other hand, they have low fuel cost
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, refueling
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 efficiency
as possible.
Description
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
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
and coal-fired
Coal-fired power station
A coal-fired power station produces electricity, usually for public consumption, by burning coal to boil water, producing steam which drives a steam turbine which turns an electrical generator...
plants. Among the renewable energy sources, hydroelectric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
, geothermal
Geothermal power
Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals...
, biogas
Biogas
Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal dung, and kitchen waste can be converted into a gaseous fuel called biogas...
, biomass
Biomass
Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....
, solar thermal with storage and ocean thermal energy conversion
Ocean thermal energy conversion
Ocean Thermal Energy Conversion uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity....
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
Dispatchable generation
Dispatchable generation refers to sources of electricity that can be dispatched at the request of power grid operators; that is, generating plants that can be turned on or off, or can adjust their power output on demand...
, but a hydroelectric plant may run low on its fuel (water at the reservoir elevation) if a long drought
Drought
A 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 basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, 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 curve
Load Duration Curve
A 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 thumb 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 plant
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.-Peak hours:...
s, typically powered with gas turbines.
Whilst historically large power grids have had base load power plant to exclusively meet the base load, there is no specific technical requirement for this to be so. The baseload can equally well be met by the appropriate quantity of intermittent power source
Intermittent power source
An intermittent energy source is any source of energy that is not continuously available due to some factor outside direct control. The intermittent source may be quite predictable, for example, tidal power, but cannot be dispatched to meet the demand of a power system. Examples of intermittent...
s and peaking power plant.
Economics
Power plants are designated baseload based on their low cost generation, efficiency and safety at rated output power levels. Baseload power plants do not change production to match power consumption demands since it is more economical to operate them at constant production levels. Use of higher cost combined-cycle plants or combustion turbines is thus minimized, and these plants can be cycled up and down to match more rapid fluctuations in consumption. Baseload generators, such as nuclear and coal, often have very high fixed costs, high plant load factor and very low marginal costs. On the other hand, peak load generators, such as natural gasNatural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
, have low fixed costs, low plant load factor and high marginal costs. Typically baseload plants are large and provide a majority of the power used by a grid
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
. Thus, they are more effective when used continuously to cover the power baseload required by the grid.
Base load power plant usage
NuclearNuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
and coal
Fossil fuel power plant
A fossil-fuel power station is a power station that burns fossil fuels such as coal, natural gas or petroleum to produce electricity. Central station 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 cost
Marginal cost
In economics and finance, marginal cost is the change in total cost that arises when the quantity produced changes by one unit. That is, it is the cost of producing one more unit of a good...
s. Because they require a long period of time to heat up to operating temperature
Operating temperature
An operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the...
, 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, refueling
Nuclear fuel
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available...
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 efficiency
Energy conversion efficiency
Energy 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.-Overview:...
as possible.
See also
- Capacity factorCapacity factorThe net capacity factor or load factor of a power plant is the ratio of the actual output of a power plant over a period of time and its potential output if it had operated at full nameplate capacity the entire time...
- Energy demand managementEnergy demand managementEnergy demand management, also known as demand side management , is the modification of consumer demand for energy through various methods such as financial incentives and education...
- Grid energy storageGrid energy storageGrid energy storage refers to the methods used to store electricity on a large scale within an electrical power grid. Electrical energy is stored during times when production exceeds consumption and the stores are used at times when consumption exceeds production...
- Load balancing (electrical power)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....
- Smart grid