Relying on storage or ICT? How to maintain low voltage grids' stability with an increasing feed-in of fluctuating renewable energy sources

Since the beginning of the new century our electricity system is changing rapidly. Distributed energy resources, such as wind or solar energies are becoming more and more important. These energies are producing fluctuating electricity, which is fed into low voltage distribution grids. The resulting volatility complicates the exact balancing of demand and supply. These changes can lead to distribution grid instabilities, damages of electronic devices or even power outages and might therefore end in deadweight losses affecting all electricity users. A concept to tackle this challenge is matching demand with supply in real-time, which is known as smart grids. In this study, we focus on two smart grids' key components: decentralized electricity storages and smart meters. The aim of this study is to provide new insights concerning the low diffusion of smart meters and decentralized electricity storages and to examine whether we are facing situations of positive externalities. During our study we conducted eight in-depth expert interviews. Our findings show that the diffusion of smart meters as well as decentralized electricity storages is widely seen as beneficial to society. This study identifies the most important stakeholders and various related private costs and benefits. As private benefits are numerous but widely distributed among distinct players, we argue that we face situations of positive externalities and thus societal desirable actions are omitted. We identify and discuss measures to foster diffusion of the two studied smart grid key components. Surprisingly, we find that direct interventions like subsidies are mostly not seen as appropriate even by experts from industries that would directly benefit from them. As the most important point, we identified well-designed and clearly defined regulatory and legal frameworks that are free of contradictions. --smart meter,decentralized electricity storage,smart grid,externality

Design and management of an Integrated Thermal Energy Storage System

openNowadays our society is experiencing an energy transition, in which renewable energy sources are assuming a newer and more central role in the energetic mix. In these scenarios, to boost the decarbonization and the usage of sustainable energy systems, Thermal Energy Storage Systems will play a fundamental role. In fact, given the discontinuous and intermittent behaviour of renewable sources, storage devices allow the mitigation of these effects and the enhancement of the electrical grid. These devices can find room not only for electrical applications, but even in the residential and industrial sectors. In this Master's thesis, the scope is to individuate how it is possible to size and manage, in an optimum way, Thermal Energy Storage Systems, starting from the production curves of a renewable energy sources power plantNowadays our society is experiencing an energy transition, in which renewable energy sources are assuming a newer and more central role in the energetic mix. In these scenarios, to boost the decarbonization and the usage of sustainable energy systems, Thermal Energy Storage Systems will play a fundamental role. In fact, given the discontinuous and intermittent behaviour of renewable sources, storage devices allow the mitigation of these effects and the enhancement of the electrical grid. These devices can find room not only for electrical applications, but even in the residential and industrial sectors. In this Master's thesis, the scope is to individuate how it is possible to size and manage, in an optimum way, Thermal Energy Storage Systems, starting from the production curves of a renewable energy sources power plan

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