power supply

from Wikipedia, the free encyclopedia

Energy supply identified in economy and technology , the supply of consumers with useful energy . Forms of energy or energy carriers are on the one hand line-bound energy carriers such as electricity or liquid or gaseous energy carriers such as natural or district gas and district heating , on the other hand solid energy carriers such as coal, coke or wood. Renewable energies will become increasingly important in the future .


The common, especially in Germany, the Energy Act oriented use of means by "power" only the supply of end users with wired energy sources such as ( Electricity , gas transmission , district heating ), so the " last mile " ( English downstream ).

In a broader sense, in particular in the designation as an economic sector , for example according to NACE , the term includes all energy sources and the entire value chain from the development of energy sources to distribution to end consumers. This includes all precursors such as stone and brown coal mining or oil and gas production, so the extraction of energy resources ( English Upstream ), and then long-distance transport, storage and processing. B. in pipelines and oil refineries ( English midstream ) as well as the non- pipeline distribution of solid and liquid fuels. This broad meaning is also known as the energy being.

The energy supply of biological systems, on the other hand, does not belong to the terminology described here, but is referred to as energy metabolism .


With the beginning of the use of fire in human history, energy was supplied through collective collection of wood as the sole energy source at that time . With the formation of settlements, cities and industrial centers of trade and supply won with fuels such as wood, coal , train oil , and later petroleum , natural gas and electrical energy are becoming increasingly important. In highly industrialized countries have since the 19th century companies engaged in the provision of technically easily usable and economically outstanding controllable energy for general consumption. The focus here is on the inexpensive and reliable generation of electrical energy and its transmission to the individual consumers . The procurement, transport and transformation of fuel for heating purposes is also an important industry.

The world energy demand is a statistical value of the sales data of all energy supply companies. It has increased significantly in recent years and decades. It says nothing about how the ecosystems change as a result of the transformation processes. It is foreseeable, however, that the current (2012) practiced handling and consumption of energy will not be able to supply the entire world population at the level practiced by the industrialized countries.

Energy sources in Germany from 2005 to 2007

Energy sources

The most important energy source is nuclear fusion , which takes place in the sun and whose energy arrives on earth as electromagnetic radiation . Conversion processes turn this solar radiation into other forms of energy such as biomass , wind energy , water energy and, in the long term, fossil fuels . The use of renewable energies is based directly or indirectly primarily on this solar radiation.

A source of energy that is independent of solar radiation are radioactive decay processes in the earth's interior, which are the main source of energy when using geothermal energy. A nuclear power plant also uses the artificially created splitting of atomic nuclei as an energy source.

Another source of energy is the earth's rotation , the energy of which can be used in tidal power plants due to the associated effects ( tides ) .

Fossil energy sources

The chemical binding energy of the organic, carbonaceous substances can very easily be converted into thermal energy by burning . Most of the materials that are highly available and can easily be heated with little technical effort are hydrocarbons that initially come from the sugars of the carbon assimilation of phototrophic plants. The density of the energy released per kilogram of the starting material during complete combustion is satisfactory for fossil hydrocarbons. The fossil fuels represent a type of fuel concentrate made from prehistoric biomaterial, which has made them the preferred primary sources of energy supply.

When using fossil fuels such as oil or coal, the greenhouse gas carbon dioxide is released in very large quantities, which contributes to global warming .

Renewable energy

The energy in sunlight, wind, the earth's mantle and water can be used with the help of renewable energies. This is done using wind power plants , photovoltaic and solar thermal systems , geothermal power plants , hydropower plants and the use of biomass . While hydropower has been a technology that has been in use for a long time, other technologies such as photovoltaics or power generation using wind energy are relatively new ways of converting energy, which have only been increasingly used since the 1980s and 1990s, but with high growth rates exhibit. They are promoted in many countries with regard to environmental and climate protection as well as their CO 2 neutrality .

Wood and other biomass as carriers of energy-rich carbon compounds that are renewable using solar energy must be dried and even then have a lower specific calorific value than the fraction products from the mineral oil industry. The generation of energy sources ( biogas and biofuel ) for the purpose of energy supply on an economically relevant scale is not without problems, as can be seen from the tension between the supply of food and nature and landscape protection.

Nuclear fission

The thermal energy generated in nuclear reactors by splitting heavy atomic nuclei such as uranium and plutonium is used to evaporate water and thus to drive turbines, which then - as in all other thermal power plants - generate electricity in generators. In this way, electrical energy can be generated without the emission of gases that are harmful to the climate, such as CO 2 , although radioactive waste is generated , the final storage of which has not yet been clarified.

The Chernobyl disaster severely damaged the acceptance of nuclear power plants and in some countries such as Italy led to the withdrawal from this type of energy generation. Other states like France have not been influenced by this.

A referendum against nuclear energy was successfully held in Sweden in 1979 . The subsequent resolution of the parliament not to build any further nuclear power plants and to shut down the four existing ones by 2000 was revised on February 5, 2009: The 1980 ban on the construction of new reactors is lifted. The ten Swedish nuclear reactors may be renewed and expanded. Even after the Fukushima nuclear disaster , Sweden is sticking to the use of nuclear energy. Germany plans to phase out nuclear energy completely by 2022. In Switzerland, with the adoption of the Energy Strategy 2050 on May 21, 2017, a license ban for new nuclear power plants was issued.

Energy source

The "raw energy" energy sources such as oil and uranium is almost never used without previous conversion and is therefore always first into transportable and storable energy transformed . Only in this way can a comprehensive energy supply be created.

Electrical power

By far the most versatile type of energy is electrical energy, the basis of the electricity supply . Electrical energy can be converted into all other types of energy with very low losses and has therefore achieved supremacy worldwide. The extraordinarily universal usability of electrical energy is expressed in the wide availability of converters that convert electrical energy into thermal energy ( electrical heating ), kinetic energy ( motor ), light energy ( light source ), sound energy ( loudspeaker ), electromagnetic waves ( transmitter ), chemical forms of energy ( Electrolysis ) or convert potential energy ( electromagnet ).

The main disadvantage of electrical energy is its limited storage capacity. Although small amounts can be stored in capacitors , significant amounts of energy require detours involving losses via other types of energy in accumulators , pumped storage plants or compressed air storage . Other energy storage devices such as hydrogen or flywheels , on the other hand, are currently only used for relatively small amounts of energy (see also energy storage devices). The storage capacity of the German natural gas network for hydrogen is more than 200,000 GWh and can temporarily store the energy required for several months. For comparison: the capacity of all German pumped storage power plants is only 40 GWh. The natural gas network is suitable for the absorption of hydrogen. The storage requirement of a future power supply in Germany, 80% of which is based on wind power and photovoltaic systems, is estimated at 30,000 GWh and could therefore already be covered by the existing gas storage without any problems. The storage of larger amounts of energy to compensate for fluctuations in the power supply throughout Europe with pumped storage power plants in Scandinavia or the Alps, which is also suggested occasionally, is not feasible with the current power grids. Due to the high losses that occur with AC transmission over long distances, the current high-voltage network with 420 kV would first have to be superimposed by one with approx. 1250 kV or a high-voltage direct current transmission (HVDC) must be set up.

Other energy sources

The construction, operation and maintenance of electrical transmission networks and the electrical transmission losses generate costs. Therefore, when choosing a location for power plants, it is essential to check whether the conversion into electrical energy takes place away from the place of consumption (non-consumption generation) and is then transferred. Sometimes it is more economical, liquid or gaseous fuels such as oil, natural gas , industrial gas , district heating and district heating via pipelines ( pipeline to be transported) and to build power plants directly where the electrical energy is required (distributed generation).

The distribution of solids such as hard coal and wood or small amounts of heating oil and fuel ( gasoline and diesel fuel ) is carried out by trucks.

Energy storage

Sufficiently dimensioned energy storage systems must be built for the switch to renewable energy sources . There is currently no tried and tested economic solution for this long-term goal. Power-to-gas technology is accorded great importance as long-term storage, although only a number of test systems are currently in operation (as of 2013). Pumped storage power plants are available for storing small amounts of electricity for hours and days . There are heat accumulators for residential and commercial buildings in which solar thermal energy obtained during the warm season can be stored, so that only a small amount of additional heating is required during the winter months (see also: solar house ). The storage of fossil fuels such as natural gas or crude oil for seasonal compensation is managed with underground storage .

Energy supply company

Energy supply companies are companies that provide private households and businesses with energy in the form of electricity , district gas and / or district heating as part of the basic supply . In Germany , energy supply companies are mainly municipal utilities and regional subsidiaries of the large control area operators .

Energy supply company i. S. v. § 3  No. 18 EnWG are “natural or legal persons who supply energy to others, operate an energy supply network or have power of disposal as the owner of an energy supply network; the operation of a customer system or a customer system for the company's own supply does not make the operator an energy supply company ”.

See also


  • Wilm Tegethoff: The law of the public energy supply. ETV since 1982 (first edition), together with Ulrich Büdenbender, Heinz Klinger.
  • Wilm Tegethoff: Problems of spatial energy supply. Vincentz, Hannover 1986, ISBN 3-87870-765-7 .
  • Jochen Monstadt: The modernization of the power supply. Regional energy and climate policy in the liberalization and privatization process. Verlag für Sozialwissenschaften, Wiesbaden 2004, ISBN 3-531-14277-1 .
  • Thomas Schöne: Contract manual electricity industry. Practical design and legally secure application. Vwew Energieverlag, 2008, ISBN 978-3-8022-0865-2 .
  • Energy supply for the future. In: Technologies for the 21st Century. FA Brockhaus, Leipzig / Mannheim 2000, ISBN 3-7653-7945-X , pp. 203-297.
  • Brockhaus People, nature, technology: The future of our planet: The energy mix for the 21st century. Wissenmedia publishing house, ISBN 3-7653-7946-8 , pp. 274-395.

Web links

Wiktionary: Energy supply  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. BMWi Energy Statistics , p. 4.
  2. Sweden renews NPP
  3. ^ Nuclear power in Sweden. In: Sweden currently. March 30, 2011, inserted March 16, 2012.
  4. Nuclear power: That's why Sweden got back on it. In: Welt am Sonntag. June 19, 2011, inserted March 16, 2012.
  5. ↑ Store green electricity as natural gas (source: Fraunhofer Institute as of April 26, 2010)
  6. Adding hydrogen to the natural gas network (source: German Gas and Water Association as of October 2010; PDF file; 176 kB)
  7. Volker Quaschning : Wouldn't the light go out? In: Sun, Wind & Warmth. 07/2012, pp. 10-12.
  8. Jörg Moll: The great blackout and the strategies against it. (Film in wmv format), 3sat hitec, June 17, 2007.
  9. With 120 euros heating costs throughout the year: In the year-round solar house in Neustadt . In: Ostthüringer Zeitung . May 31, 2012. Retrieved December 13, 2013.