Important Terms from A to Z
Fuels to Generate Heat and/or Electricity
A fuel is a liquid, solid or gaseous product used to generate heat, in the heat and electricity generation sectors, or motion in the mobility sector. In the electricity generation sector, fuels are also referred to as primary energy sources. In this glossary article, we refer to fuels that are used to generate heat and/or electricity. For a description on fuels to generate motion (automotive fuels), please see separate glossary article.
A fuel to generate heat and/or electricity may be composed of one or more chemical elements. Pure chemical elements that are used as fuel include hydrogen or the nuclear fuels uranium and plutonium. Heating oil, wood and coal, for example, are composed of a number of elements – usually carbon and hydrogen – whose stored energy is primarily released by combustion.
Fuels are generally classified as follows:
|According to their state of aggregation:|
|According to its sustainability:|
The energy content of a fuel is specified as a calorific value (inferior calorific value) or gross calorific value (superior calorific value). The superior calorific value corresponds to the energy that is released through a complete combustion of the fuel with subsequent cooling of the flue gases and condensation of the vapors. So the superior calorific value also includes use of the condensation heat. The (inferior) calorific value, by contrast, is the maximum usable amount of heat that is generated during the combustion of a fuel, not including the cooling of the flue gases and heat of condensation. However, in fuels that contain no chemically bound hydrogen, both calorific values would be equal.
Germany, for example, as a resource-poor country, has to import most of its fuel. Only lignite is available domestically in sufficient amounts. Bituminous coal is mostly imported from Poland and Australia. Crude oil comes mainly from Russia, the North Sea (primarily from the offshore production fields of the Netherlands and the United Kingdom) and North Africa, and natural gas also from Russia and the North Sea.
Biofuels are an exception. Germany is rich in forests, so a large part of the demand for wood-based fuels can be covered by domestic production.
Fuels are taxed in Germany under the Energy Tax Act. Taxation is based on the volume/weight or unit of energy (MWh) of the respective fuel. Reduced rates are set for use as heating fuel as opposed to automotive fuel. According to the Energy Tax Regulation (EnergieStV) therefore, properly labeled heating oil contains various dyes: Solvent Yellow 124 and red markers. The red color is used to visually differentiate between heating oil and diesel fuel, to prevent the misuse of the former as an automotive fuel (this is known as “dieselization”).
The following tax rates apply for fuels in the heating market in Germany (status: November 2015):
|Heating oil EL||61.35 euros/1,000 l|
|Natural gas||5.50 euros/MWh|
|LPG||60.60 euros/1,000 kg|
Exception: Wood-based biofuels such as pellets, firewood, charcoal, etc. are not subject to the energy tax.
The services of GMA – Gesellschaft für Mineralöl-Analytik und Qualitätsmanagement cover the analysis of fossil and biogenic fuels in accordance with international standards.
Status: December 2015
All information subject to change. Errors and omissions excepted.