Assessment of photovoltaic generation, supply, and sustainability: a case study of municipalities in São Paulo state

Energy consumption has been increasing together with population growth and the consequences for energy production widely generate discussions under the aspect of environmental outcome and supply reliability and quality. This paper proposes a methodology that allows the estimation of the potential for cities to be more independent in terms of centralized generation and distribution of electricity considering photovoltaic sources. Sustainability and environmental performance are also discussed. The methodology aims to assess some municipalities in the São Paulo state. The results showed high potential for photovoltaic supply in those municipalities under the considered conditions indicating the possibility for structuring a decentralized generation model where cities would be more independent in electricity supply. Implementing the required photovoltaic systems would return the energy consumed during their life cycle in a relatively short period compared to their expected lifetime.

Improvements of Micro-CHP SOFC System Operation by Efficient Dynamic Simulation Methods

Solid Oxide Fuel Cell (SOFC) technology is of high interest for stationary decentralized generation of electricity and heat in combined heat and power systems (CHP) for the residential sector. Application scenarios for SOFC systems in an electricity-regulated mode play an important role, especially in places where an electrical grid connection is not available or rather unstable. The advantages of SOFC systems are the high fuel flexibility and the high efficiencies also under partial load operation compared to other decentralized power generation technologies. Due to the long, energy-consuming system heat-up and the limited partial load capability, SOFC systems do not reach the performance of conventional power generation technologies. Furthermore, stack thermal cycling is associated with power degradation and should be minimized. In this paper, the improvement of these drawbacks are investigated for hotbox-based SOFC systems in the 1 kWel-class for residential applications. Since experimental investigations of the high-temperature systems are limited, modeling tools are established, enabling the visualization of internal system characteristics and providing the opportunity to simulate system operation in critical regions. To achieve this, a methodology for dynamic SOFC system modeling in a process engineering manner is developed based on the modeling language Modelica. A suitable approach is particularly important for modeling and simulation of the strong thermal interaction between the hot system components within the hotbox. The parametrized and validated models are used for the investigation of different dynamic effects, such as the system heat-up and the operation in low partial load points. A second reduced thermal system model aims for annual simulations of the SOFC system together with a battery to investigate the number of thermal cycles and the advantage of a hot standby operation. As a result, it is found that an adequate control of the power input at the start-up device and the cathode air flow has a high improvement potential to increase the stack heating rate and accelerate the heat-up in an energy-saving way. The hotbox-internal thermal management is identified as a crucial issue to reach low partial load points. To avoid the risk of stack cooling, lower heat losses and/or additional heat sources are of importance. Furthermore, the robustness of the tail gas oxidizer is found to be crucial for a higher load flexibility during partial load and the end of life stack operation. The annual simulation results indicate that operating the battery hybrid system with a hot standby mode requires much lower battery capacity for a high grid independence and a complete avoidance of system shutdown and associated power degradation.

Renewable Energy Sources in the Decentralized Power Supply System of Several Districts in Cote dIvoire

The article summarizes the results of research works carried out by the authors on matters concerned with assessment of decentralized energy. The main aim of the study was to estimate the influence of decentralized generation on the life activities of the selected districts and the country as a whole. To identify the effects from introduction of decentralized generation technologies, a case study analysis method was used. The analysis was carried out on the basis of 3 from 14 districts of Côte d’Ivoire, which are the least electrified points and are regarded to be strategic ones in transporting power to the neighboring countries. As a result of the study, technological, economic and social effects have been identified. The technological effects include achieving better reliability of power supply, reducing the environmental burden, including emissions and others. The economic and social effects are that power supply becomes available to consumers, and the electricity becomes cheaper.

Prospects for Renewable Energy at the Regional Level (in the Example of the Kemerovo Region) in the Context of Decarbonization and Decentralized Generation

The Kemerovo region is one of the largest regions for coal mining. The region’s economy is growing every year, but residents of remote communities still use diesel generators (which negatively affects the environment and essentially means poor use of it) or do not have access to centralize electricity. The Advanced Development Programme for Electricity Systems in the region has a limited budget and does not cover all regions. Most of the existing infrastructure has been in use for more than 25 years, which increases the relevance of decentralized generation. Renewable energy not only reduces emissions significantly, but also addresses the challenge of providing energy to rural people. The authors studied the feasibility of installations of solar panels, wind and hydro installations of low capacity in the Kemerovo region. As a result of the study, it was concluded that the use of hydropower plants will provide 6% of rural Residents of Tisul and Tashtagol municipal districts with electricity. Solar panels and collectors can be used in almost any area, but it is economically justified to link their installation with tourism development programs in the region. As far as wind farms are concerned, they are under-powered for objective reasons, and decisions about their use require further research.

Contribution of DGs in the stability and voltage drop reduction for future MV network in desert regions

<p>Day by day, the integration of decentralized generation in medium voltage networks becomes more important during the last years and even in the near future. This increase causes, at the same time, several negative effects and rarely positive impacts on the stability of the network. Therefore, this work aims at analyzing the impact of ambient temperature on radial distribution network parameters’ e.g.: voltage drop and stability voltage level (index). Based on MATLAB program, different analyses of distributed generation (DG) insertion influence’s on voltage drop in the radial distribution feeder, as well as the influence of climatic conditions such as ambient temperature on network parameters. The Integration of Photovoltaic DGs in MV networks can play an important role in reducing the global warming effect (in voltage drop, and voltage stability index) especially in radial distribution feeder. Furthermore, it protects network’s parameters if its location and power are well selected.</p>

The Present Trends and Challenges in Renewable Energy Sources Connected to a Grid

Smart grids are alterations of the traditional power grids where the monitoring and control of the electricity system are faster and easier than before due to their automated self-healing and sensing processes. However, their primary target is two-way communication, which is only feasible if the decentralized generation of power will exist alongside the national grid. In that light, this report first gives a comprehensive description of smart grids and their history. Afterward, it examines the two major groups of challenges to the penetration of the technology; that is technical and regulatory, policy, and economic challenges. Case studies from the U.S., Canada, Korea, California, and Sweden are used to illustrate the discovered trends and challenges to renewable energy sources connected to grids and demonstrate possible solutions. The research design employed in the study is diagnostic since the problem, its history, and solutions are all reviewed in the report. The study's recommendation is policy interventions to solve both the regulatory and technical challenges to the proliferation of gridded renewables.