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Time in the Sun: The Challenge of High PV Penetration in the German Electric Grid

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Energy supply systems are facing significant changes in many countries around the globe. A good example of such a transformation is the German power system, where renewable energy sources (RESs) are now contributing 25% of the power needed to meet electricity demand, compared with 5% only 20 years ago. In particular, photovoltaic (PV) systems have been skyrocketing over the last couple of years. As of September 2012, about 1.2 million PV systems were installed, with a total installed peak capacity of more than 31 GWp. During some hours of 2012, PV already contributed about 40% of the peak power demand. It seems that Germany is well on the way to sourcing a major portion of its energy needs from solar installations. PV must therefore provide a full range of services to system operators so as to replace services provided by conventional bulk power plants.
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Progress in Photovoltaics: Research and Applications, 27th EU PVSEC, special issue, frankfurt, germany, 2012. t. stetz, f. marten, and m. Braun, "improved low voltage grid-integration of photovoltaic systems in germany
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