Today, in the 6th ScienceBeer, Ana Maria and Olga were our Science Brewers. Ana Maria is a PhD student in TU-Dresden and works on power quality in the power grids. Olga is a PhD student in TU-Dresden and works on power quality in the power grids. They told us very interesting facts about various distructive phenomenons which may happen in a power grid, from flickers and interruptions to harmonics. Then we learned how we can deal with this phenomenons, which type of data should be collected and how we should analyse them! They also brought us a full set of measuring and monitoring devices, therefore we had the chance to experience all of these theoretic facts in real-life demonstrations. Thank you Ana Maria.Thank you Olga.