Articles for "Erneuerbare Energien"

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Energy | 30. August 2010 | posted by Jan Oliver Löfken | 1 Comment

Energy question of the week: Can the greenhouse gas carbon dioxide be stored safely underground?

Coal-fired power stations release more carbon dioxide per kWh than any other fossil fuel facility, and Germany has a large number of just this sort of power station. It is estimated that around 40 billion tons of coal are stored in potential open cast deposits in Lusatia and the Lower Rhine Basin. That makes up 14 percent of world reserves. The question is, can the carbon dioxide emissions be captured and stored underground? read more

Energy | 23. August 2010 | posted by Jan Oliver Löfken | 2 Comments

Energy question of the week: Can wind turbines also float on the open sea?

The twelve offshore wind turbines that make up the 'alpha ventus' wind farm, 45 kilometres to the north of the North Sea island of Borkum, can generate sufficient electricity for 50,000 households. Like all other wind farms in the North Sea, these turbines are installed on firm foundations at water depths of between 30 and 50 metres. However, not all coastal countries have such a flat and shallow seabed immediately off their coastline. Might it not be a great deal simpler and less expensive to install wind turbines on floating platforms? read more

Energy | 16. August 2010 | posted by Jan Oliver Löfken

Energy question of the week: Is any country already able to meet all of its energy needs from renewable sources?

A growing volume of energy originating from renewable sources is being used right around the world – from Europe to America to China. This trend is especially widespread in the electricity-generation sector. Over the last couple of years, the USA and the countries of the EU have been building more power station capacity based on wind, water and solar energy than they in conventionally fuelled power stations, – that is, coal, gas or uranium. However, is any country already able to meet all of its energy needs from renewable sources? read more

Energy | 09. August 2010 | posted by Jan Oliver Löfken | 11 Comments

Energy question of the week: Which type of electricity generation has the least impact on climate?

Coal-fired power stations burn lignite or, for the most part, coal imported from overseas. Solar cells need crystalline silicon that first needs to be extracted from quartz, an energy-intensive process. Therefore, when examining the climate compatibility of power generating plants, it makes sense to not restrict the analysis just to the operation of the plant. Instead, the total energy required should be considered across the entire service life of the plant, typically in excess of 30 years. Viewed against this benchmark, which type of power plant has the best environmental credentials? read more

Energy | 02. August 2010 | posted by Jan Oliver Löfken

Energy question of the week: Can we secure our fuel supply with the help of algal blooms?

Every hot summer, gigantic carpets of blue algae spread across the Baltic, much to the disapointment of seaside visitors looking for a quick dip in the cool water. Cyanobacteria inhabit the yellow-green plumes and can lead to poisoning if ingested. However, these same microorganisms can also produce flammable hydrocarbon chains known as alkanes and alkenes. Might they be suited to diesel and petrol production? read more

Security | 19. July 2010 | posted by Jan Oliver Löfken

Energy question of the week: Does the oil spill in the Gulf of Mexico mean the end of deep sea drilling?

Since disaster struck the Deepwater Horizon drilling platform in the Gulf of Mexico on 20 April 2010, up to nine million litres of crude oil have been gushing into the sea every day. It remains to be seen whether the recently installed 40-ton cap can really stop the majority of the oil flowing from the wellhead, 1500 metres under the sea. The spill will only be stopped definitively when the relief wells are completed in mid-August. But is this catastrophe the beginning of the end for deep sea drilling? read more

Energy | 05. July 2010 | posted by Jan Oliver Löfken

Energy question of the week: How does a solar cell work?

At present, commercially available solar cells made from polycrystalline silicon operate with an efficiency of 20 percent. Special solar cells composed of other semiconductors such as gallium arsenide have already passed the 40 percent efficiency barrier. In contrast, cells based on organic materials or pigments convert only 10 percent of the sunlight into electrical current at best. All of these use the photovoltaic effect, but what actually happens in the process? read more

Energy | 28. June 2010 | posted by Jan Oliver Löfken

Energy question of the week: Can burning ice solve our energy problems?

Crude oil, coal and natural gas are not the only fossil fuels hidden deep below the surface of the Earth. Right around the globe, enormous quantities of methane hydrates can be found as many people already know, especially since Frank Schätzings famous novel 'The Swarm' (Der Schwarm). This white combustible ice consists of water and methane gas. If thawed in a controlled fashion, many billions of tons of methane could be obtained from it. The question is: do methane hydrate have a genuine role to play in our energy future? read more