Electricity generation
As power generation and power production is referred to in common parlance and energy on the technical production of electrical energy. This energy is transported via power grids to the consumers. In the physical sense of energy is not generated, but there is a transformation from another form of energy such as, for example, instead of of solar energy and the chemically bound energy of combustible fossil fuels.
- 4.1 International comparison
- 4.2 Gross electricity generation by energy sources in Germany
- 5.1 The price of electrical energy in Germany 5.1.1 final cost
- 5.1.2 production costs
- 5.2.1 The price of electricity in Europe
- 5.2.2 Which power plant supplies power to whom?
- 8.1 See also
- 8.2 Literature
- 8.3 External links
- 8.4 References and notes
General
Power generation from a physical perspective
Physically, the electric current per unit time flowing electric charge. The energy is calculated as the power divided by the electrical voltage and the time. Since the physical total energy remains constant according to the energy conservation law, the concepts of power or energy, from a physical point of view is incorrect. It is a conversion of various forms of energy, usually the conversion of kinetic energy into electrical energy by a generator. The electrical energy is then usually routed via a mains supply to the connected devices to meet their electricity needs. The majority of the electricity generation is done on an industrial scale in power plants.
Electricity from the energy industry perspective
General Linguistically and the energy of the current term of derogation to the common unit of kilowatt hours used ( " power consumption " instead of energy use) by the physical definition in terms of electrical energy. Power generation thinks in energy economic sense to provide electrical power using energy factors of production ( coal, gas, hydro, wind ...) and non-energy factors of production ( labor, emission trading certificates ... ).
Under gross electricity generation is taken to mean the total electrical energy generated. Taking away their own consumption of power plants starting, we obtain the net power generation. For example, the personal use of coal power plants is about 10 % and that of nuclear power plants around 5 % of the electrical energy produced by them, the energy requirements of nuclear power plants persist for several years remains even after the termination of electricity ( " shutdown" ) because the reactor must be further cooled and protected.
Importance
Electrical energy is the most versatile usable energy source, which also can be converted into other forms of energy with very low losses. It is a prerequisite for any modern industry and can not be replaced by other energy sources without taking high losses. A power outage brings experience, every economy to a halt and must therefore remain largely limited.
Is of great importance in the provision of electric energy comes to the rotating electrical machines. In thermal power plants mostly three-phase synchronous generators are used. Also in wind turbines and hydroelectric plants three-phase synchronous generators application. There, however, three-phase asynchronous generators are also used.
Main advantage is the ability to coat an entire continent such as Europe with a grid, in which the electric current can be distributed with low losses and increased by the number of connected power plants, the redundancy and hence the security of supply.
Main disadvantage of the electric current is the fact that - economically speaking - can be saved only vanishingly small amounts of energy directly. Only by consuming transformation into other forms of energy, for example by pumped storage power plants can avoid that the electrical energy generated must match at every moment exactly with the amount consumed.
Electrical energy is largely the sole bearer, to carry the energy of a hydroelectric power plant, a wind turbine or a nuclear power plant in industrialized areas. Alternatively, there is the hydrogen economy, which has heretofore been formulated only as a concept.
Historical
The triumph of the electrical energy supply began after 1882 by the construction of power plants with electric generators. First, there were independent stand-alone solutions. Very quickly was recognized the advantages of AC-powered electricity grids, because they are no longer so strongly depended on the reliability of individual power plants. In Germany, two almost independent power networks were:
- The public network with 50 Hz and
- The traction power network with 16 2/ 3 Hz for the railroad.
Some power plants have been equipped with separate generators and could generate electricity for both systems.
Today, the electricity generation in Germany has been privatized, although there are over 800 individual current provider, but about 80 % of electricity generated by the four major energy company RWE, E.ON, EnBW and Vattenfall are realized, thus forming a homogeneous oligopoly.
Gross electricity generation by energy source
International comparison
Global were produced 22158.5 billion kWh of electrical energy in 2011. About two-thirds of the total production comes from the burning of fossil fuels, approximately 20% were generated renewably and won just under 12% by nuclear energy.
The following table shows the gross electricity generation by energy source in 2008 in different countries over.
( K. A.: not specified )
Gross electricity generation by energy sources in Germany
The gross electricity generation by energy source in Germany for the years 1990, 2000 and 2007 to 2013 is shown in the two following tables.
The mix of the individual utilities differs from these average values greatly.
Electricity industry
The price of electrical energy in Germany
Final cost
Electricity prices depend on the reference amount. Industrial electricity prices for large quantities are probably the best measure of the production costs. They totaled 2007 with a minimum purchase of 70,000 MWh 6.6 ct / kWh, plus a 4.5 ct / kWh taxes and fees must be added. Total price of 11.1 cents / kWh.
An average-size home in Germany annually consumes about 3500 kWh and paid for it in 2008, 12.98 ct / kWh to the electricity supplier. There are also 8.67 ct / kWh and taxes. Total price 21,65 ct / kWh.
Production costs
The prices in the table above are partially occupied, but only scanty and lacks the calculation bases. For example, has an old power plant, which has already paid for its cost of capital, significantly lower electricity costs than a new power plant. In addition, the production costs are also dependent on whether external costs such as decommissioning and disposal costs are factored.
It must also be borne in mind that the fuel costs are not stable and that the capital and maintenance costs vary within a type of power plant.
Biogas CHP and wood heating plants also the fuel costs are apportioned 100% on the electrical energy generated, whereas in reality, the waste heat of these power plants usually is shared in local heating systems. Considering a power ratio ( electrical: thermal) of 50:50 ( for biogas CHP ) or 20:80 (with wood HKW ), the fuel cost reduced to 2.5-4 ct / kWhelectr. (Biogas CHP ) or 1.6-2 ct / kWhelectr. (Wood HKW ). A similar calculation can of course be recognized even at CHP with other fuels (eg gas or oil).
Wind and photovoltaic not the actual production costs are given, but the maximum feed-in tariffs. This legally guaranteed payments are reduced from year to year, partly also during the year.
Electricity trading in Europe
In Europe it is common for some time that electrical energy is traded like any other commodity. Consequences of cross-border electricity trade show at an incident on September 28, 2003: A high-voltage line in the Alps was interrupted, which had a power outage in northern Italy consequence. As a rule, the connections run but easily and also serve to ensure the power supply during the regular shutdown of power plants without interruption for maintenance purposes.
The price of electricity in Europe
Electricity prices in Europe vary considerably. Cause this include different levels of taxes and other charges. Leaders are Denmark, Cyprus, Germany and Belgium. The price of household electricity was 2012 in these countries more than 23 cents per kWh (including all taxes and charges in an annual consumption 2500-5000 kWh). Was particularly favorable household electricity in 2012 with less than 13 cents per kWh in Bulgaria, Romania, Estonia and Lithuania ( see table ).
Which power plant supplies power to whom?
Basically, the nearest power plant supplies the majority of energy consumed. Figuratively, you can imagine it like a mountainous landscape: " press " the power plants, the mountain peaks upwards, consumers (cities, industrial plants ) down. Energy flows - as well as about heaped water - the steepest downhill path and disappears there. In physics it is called the gradient of a scalar field. It has never been observed that water turns uphill and downhill flows to reach a very specific valley. The energy flow behaves the same.
In the context of green electricity again, the question arises as to achieve some electricity suppliers to purchase electricity from a very specific, often distant power plant. Electricity from a distant power plant is not physically possible, unless you disconnects itself from the mains power source and creates a separate line to the desired power plant. Should be understood in this context important that the current market allows an accounting separation, ie a consumer takes from the grid the same amount of energy, which he bought from a power generator, and this feeds into the grid. Physically, the electric energy comes mostly from the nearest power plants, the trade-off " money for goods" takes place on the simplified " Stromsee " an interconnected network with the selected current provider.
In the cases of Kassel and Wolf near Kassel that would be the nuclear power plant Grohnde, local waste to energy plant, local district heating power plants, local CHP and local photovoltaic systems. Depending on the wiring, the distant storage power plant Werdohl - Elverlingsen and power plant Staudinger Grosskrotzenburg could also supply small amounts. Only for peak demand, the pumped storage power plant switched to Waldeck. The probability that the electrical energy but physically comes from Swedish or Austrian hydropower plants is low.
Local and mobile power generation
A generation in the vicinity of the consumer, such as within or near residential areas and industrial plants are referred to as distributed generation. If electricity is distributed over a spatially limited power supply, it is called an island grid.
If electricity is not distributed over a power grid, but locally produced and consumed, so it is called a stand-alone solution. Examples include electricity generators, solar cells and fuel cells, but also the alternator and bicycle dynamo in a car and bicycle. All wireless devices are typically used batteries or batteries as energy storage for use. Fuel cells provide a mobile power through conversion of chemically bound energy.
Health effects
Different forms of electricity generation have significantly different effects on health. This can occur due to accidents and air pollution in normal operation. According to the table the number of deaths in public is by accidents due to air pollution and accidents in the European Union in the nuclear energy significantly lower than lignite or hard coal. Most diseases caused by air pollution generated per terawatt hour caused in the European Union by lignite and hard coal, followed by oil and biomass.