Energy question of the week: What part does natural gas play in meeting Germany’s energy requirements?
Whether used for heating, as a vehicle fuel or for power generation in gigantic turbines, natural gas plays a central role in Germany’s national energy supply. With consumption at 100 billion cubic metres a year, its use – and also importation – has almost doubled since 1970; and this trend is still growing. But does such a development make sense?
Natural gas is rich in methane and has significant advantages over crude oil and coal. It can be used very efficiently for electricity generation in flexibly controlled gas power stations, which can be brought fully online in just a few minutes in response to peak demand or the variability of wind power. Siemens recently tested the largest gas turbine in the world, with a capacity of 340 megawatts, at Irsching, near Ingolstadt. Coupled with a steam turbine, the installation is capable of an efficiency of over 60 percent – a value that coal-fired power stations can only dream of.
Installation of Siemen’s newly developed gas turbine, the largest in the world, at Irsching near Ingolstadt, Bavaria. Credit: Siemens Pressbild.
Natural gas reserves for more than 100 years
In contrast with crude oil the maximum exploitation of natural gas has not yet been reached. The German Federal Institute for Geosciences and Resources (Bundesanstalt für Geowissenschaften und Rohstoffe; BGR), based in Hanover, estimates global conventional natural gas reserves at 516 trillion cubic metres. One third of that is already exploited. Around 3.1 trillion cubic metres are consumed every year, so these reserves will last for more than 100 years at current rates of consumption. The most important reserves are in Siberia and the Middle East; new ones are always being discovered, like the estimated six trillion cubic metre reserves recently found in the Nile Delta, Egypt.
Natural gas and the climate
Burning natural gas – like any other fossil fuel – releases the greenhouse gas carbon dioxide. But thanks to the efficiency of gas turbines, emissions per kilowatt-hour of generated electricity are lower than those of coal-fired power stations. But leaking natural gas has a very large environmental impact, since it is composed largely of methane which, once it is released into the atmosphere, makes a 25 times greater contribution to global warming than carbon dioxide.
Natural gas reserves: The most important countries and regions in 2008, Source: German Federal Institute for Geosciences and Natural Resources (BGR).
Pipelines, tankers or refrigerated ships
Delivering this valuable fuel to its users is very expensive. For the EU, the controversial Baltic pipeline, currently under construction over the 1220 kilometres from Vyborg, near Saint Petersburg, to Lubmin, in Greifswald, Germany, is of central importance. However, this pipeline only increases Europe’s dependence on Russian gas. So the EU is also promoting the Nabucco pipeline project. The decision whether to build this 3300-kilometre long pipeline through Turkey and Eastern Europe will be taken this year. If it is built, the huge natural gas deposits around the Caspian (Iran, Turkmenistan, Kazakhstan, Azerbaijan) will provide a more secure energy supply for Europe.
For more information on natural gas and its exploitation:
Federal Institute for Geo-Sciences and Resources (BGR)
The DLR Energy question of the week in 'The future of energy' Year of Science
The Federal Ministry of Education and Research (BMBF) has given the Year of Science 2010 the motto 'The future of energy'. For this reason the science journalist Jan Oliver Löfken will this year answer a question on the subject of energy in his blog each week. Do you have a question about how our energy supply might look in the future? Or do you want to know, for example, how a wave power plant works and how it can efficiently generate electricity? Then send us your question by email. Science journalist Jan Oliver Löfken will investigate the answers and publish them each week in this blog.
Top image: Siemens Pressbild.