Grid Capacity Issues with Distributed Generation

Climate change is more evident than ever as reflected in The European union's environmental directives which say that the carbon emission must be reduced by 20% and 20% of the used energy must come from renewable energy sources until 2020. In Germany political decision has been made that the nuclear power will be replaced by renewable energy in long term. The purpose of the Master Thesis is to investigate how high penetration of photovoltaic affects the electrical grid on a distribution level concerning active power and map the potential for different renewable energy sources in Germany. Using a simulation model and grid data received from E.ON the goal is to map what problems that may occur and evaluate different measures for solving the problems. The data and information collection have been done by interviews and literature studies. The simulation program that has been used is DIGSILENT Power Factory where all the simulations have been static ones. Different load profiles for households have been handed by an internal source in E.ON and evaluated before inserted in the simulations. The studied measures for balancing the active power are battery storages of different technologies, load shifting and biomass power plants. The investigated battery technologies were Li-ion batteries, Lead-acid batteries and Vanadium Redox flow batteries. The main purpose of evaluating three different technologies is the costs for each technology. Battery storages and load shifting have been used for all load profiles, the biomass power plants have been used while the PV output has been low. The results showed that Germany is able to increase its wind and PV output in the future. Implementation of battery storage and load shifting will balance the grid and less power will be taken from the transmission grid. Load shifting is very hard to analyze and utilize but assumed to have low capital costs. Load shifting in households is also a very immature technology. Storing energy is the most effective measure for balancing the active power because of the valuable property to store energy and use when it is needed. But the costs of battery storages are high even if no costs of power electronics were included. Implementation of a 10 MW biomass power plant will balance the active power while low production of PV and high demand

PIXE Detection Limits for some Aerosol Collection Substrates by Excitation with protons and 4He2+ Ions from a 3 MV Tandem Accelerator

Comparisons of PIXE detection limits for K, X rays using 2-5 MeV protons and 7-8 MeV 4He2+ ions as projectiles have been performed. The comparisons have been made for common aerosol backings. According to simple theoretical considerations regarding X-ray production cross sections and the production of background radiation, detection limits for 4He2+ should be two to four times lower than for protons for equal vefoeity projectiles of equal numbers. However, the background in X-ray spectra arising from gamma-quanta being Compton scattered in the Si(Li) detector can strongIy affect the detection limits. The detection limits using protons and 4HeZ+ ions from a 3 MV electrostatic tandem accelerator are determined and discussed

An Analytical Procedure for Determining Chromium in Samples of Airborne Dust

Abstract in UndeterminedA method is described for assessing occupational exposures to chromium aerosols; it involves four procedures. The first, proton induced X-ray emission (PIXE), measures the total chromium,. The second, electron spectroscopy for chemical analysis (ESCA), measures the oxidation state of the particle surfaces, and the third, which uses sym-diphenylcarbazide (DPC), measures the proportion of water-soluble chromium VI. The fourth, transmission electron microscopy (TEM), provides information about the size and shape of the particles and guides the interpretation of the ESCA-data.The multielemental nature of PIXE-analysis is advantageous in eliminating the possibility of interference in the DPC-method and in eliminating chromium compounds from the tentative list of existing health hazards in the smoke. These methods were applied to the analysis of samples of fume produced in welding, and information was obtained for the amounts of soluble and insoluble chromium (III and VI) in samples of different aerosols