Natural gas, a fossil fuel used primarily for warming water and heating buildings, can be divided into two types in Germany, depending on its energy content: high-calorific gas (H-gas) and low-calorific gas (L-gas). While both types are composed mostly of methane, L-gas has a lower energy content, generally costs less, and consists of 80-87 percent methane. H-gas has a methane content of 87-99 percent and costs more than L-gas due to its higher energy content. Found in Northern Germany and the Netherlands, L-gas has higher quantities of nitrogen and carbon dioxide than H-gas. Russia, which supplies natural gas to Germany, has large H-gas reserves. Germany is switching from L-gas to H-gas in many places because its major supplier of L-gas, the Netherlands, has nearly exhausted its reserves. To accommodate this transition, Germany is updating its gas infrastructure by constructing new pipelines and compressor stations and retrofitting end-use appliances.
(Braunkohle) Lignite, or brown coal, has been formed under relatively little pressure, has a high water content, and is extracted by opencast mining in Germany – mainly in Lusatia in the east, and North Rhine-Westphalia in the west. Lignite accounted for about 23 percent of Germany’s power production in 2017, and is the most CO2-intensive fuel in the energy mix. Because lignite is humid and heavy, it is too expensive to transport over long distances, and so normally it is burned in power stations near the mines. These power stations are high on the list of Europe’s largest CO2 emitters. The economies of the regions where it is mined – Lusatia in particular – are heavily dependent on lignite.
(Laststeuerung) See → demand-side management
(Ringflüsse) Electricity tends to follow the path of least resistance. When power is produced in one place and purchased by a consumer elsewhere, it tends to flow along the most direct power lines between the two points. But if the route is congested, it will take a detour through other parts of the grid, looping around the blockage. Grid congestion in Germany means that at times of high renewable generation, these loop flows result in destabilising surges of power through the grids of neighbouring countries.