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TECHNOLOGYSPOTLIGHT
Advances in technology across industry
E.ON to build one of the first commercial battery systems for the UK grid
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.ON has been awarded a contract with the British transmission system operator National Grid to support the power grid’s stability with an innovative battery solution. With the strong growth of weather-dependent renewable sources such as wind and solar, the amount of power fed into the grid is becoming increasingly volatile. National Grid had therefore launched a tender for a new service to deal with volatile fluctuations. As one of the first
of its kind in Great Britain, E.ON’s battery system will help balance demand and supply in real time ensuring that the power supply and quality is maintained. The solution makes it even possible to increase the share of renewable energy in the grid. The 10 megawatt (MW) lithium-ion battery with a size of four shipping containers has an equivalent power of roughly 100 family cars. E.ON will build the 10 MW battery at E.ON’s Blackburn Meadows Biomass CHP
and District Heating site near Sheffield. The system is planned to be operational by the start of 2018. Visit: www.eon.com
Power from body heat
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Beam me up to the video conference
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hen science fiction heroes communicate, they don‘t use landlines or cell phones. The caller simply appears in virtual form in the middle of the room; full sized and three dimensional. For researchers at Fraunhofer, this vision is already within reach. Scientists at the Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, HHI in Berlin have developed a method by which the realistic image of a person can be transmitted in a virtual world; and just like in science fiction movies, the image appears full sized and three dimensional. The image can be viewed from different directions and the viewer can even walk around it. To produce this three-dimensional impression the researchers have developed a stereo camera system that records the person with two lenses. However, recording a person in detail from all directions takes more than one camera. “We are currently using more than 20 stereo cameras to map a human,” says Oliver Schreer, head of the research group ‘Immersive Media & Communication’ at HHI. Each camera only captures a part of the person. The challenge is to merge the individual camera images together so that a realistic overall picture is produced. To do this the researchers have developed algorithms that can quickly extract depth information from the stereoscopic camera images. This is necessary in order to calculate the 3D form of a captured person. The computer calculates a virtual model of the human, which is then transferred into the virtual scene. The cameras perceive the surface shape with many details. In this way even small wrinkles, e.g. on the clothes of the person, can be shown. Visit: www.fraunhofer.de 22 Industry Europe
lectronics integrated into textiles are gaining in popularity: Systems like smartphone displays in a sleeve or sensors to detect physical performance in athletic wear have already been produced. The main problem with these systems tends to be the lack of a comfortable, wearable source of power. Chinese scientists are now aiming to obtain the necessary energy from body heat. In the journal Angewandte Chemie, they have introduced a flexible, wearable thermocell based on two different gel electrolytes. Our muscle activity and metabolism cause our bodies to produce constant heat, some of which is released through the skin into the environment. Because of the relatively small temperature difference between skin (approximately 32°C) and our surroundings, it is not so easy to make use of body heat. Previous thermoelectric generators produce too little energy, are costly, or are too brittle for use in wearable systems. Thermocells with electrolyte solutions are difficult to integrate into extensive wearable systems. A team led by Jun Zhou at Huazhong University of Science and Technology (Wuhan, China) has now found a solution to this problem: thermocells with gel-based electrolytes. The researchers are making use of the thermogalvanic effect: if two electrodes in contact with an electrolyte solution – or an electrolyte gel – are kept at different temperatures, a potential difference is generated. The ions of a redox pair in the electrolyte can rapidly switch between two different charge states, accepting or releasing electrons at electrodes with different temperature. In order to use this to produce a current, the scientists combined two types of cells containing two different redox pairs. Each cell consists of two tiny metal plates that act as electrodes, with an electrolyte gel in between. Because of the choice of these redox pairs, in cell type 1, the cold end gives a negative potential, while in type 2, the cold end gives a positive potential. Visit: www.hust.edu.cn
