Analyzing the Energy Utilization Efficiency of Renewable Energy Resources. Part 2: Exergy Analysis Method

2006 ◽  
Vol 1 (4) ◽  
pp. 355-366 ◽  
Author(s):  
Arif Hepbasli ◽  
Zafer Utlu
2005 ◽  
Vol 9 (3) ◽  
pp. 15-23 ◽  
Author(s):  
Fajik Begic ◽  
Anes Kazagic

Along with the current processes of restructuring of Energy power system of Bosnia and Herzegovina, liberalization of the electricity market, and modernization of the existing power plants, Bosnia and Herzegovina must turn to the utilization of renewable resources in reason able dynamics as well. Respecting this policy, the initial Valuation of the potential of renewable erg resources in Bosnia and Herzegovina is per formed. The methodology of evaluation of wind energy utilization is presented in this paper, as well as some other aspects of utilization of the renewable energy resources in Bosnia and Herzegovina. Implementation of selected projects should improve sustainability of energy power production in Bosnia and Herzegovina, by reducing the total emission of carbon dioxide originated from energy power system of Bosnia and Herzegovina.


In the modern era, most of the utility grid is connected with Renewable Energy resources (RERs). In addition to this, many power electronic converters and reactive power compensating devices are also incorporated into the existing grid. This makes the system complicated. Penetration of renewable energy resources affect many power system parameters like grid stability, quality of power, reactive power balance and Sufficient energy utilization. However, the Distributed Generation (DG) towards the power electronic interface creates some critical power quality events such as reactive power management, harmonics and voltage profile which makes the distributed system become a polluted one. This paper depicts the review of modelling and incorporation of various reactive power compensating devices like TCSC, SVC and STATCOM into RES. Power generation model of solar, wind and fuel farm is discussed in this paper. Reactive power compensating devices and its location and sizing are important for the stable and secure operation of the electric grid. Consequently, power quality issues, real-time interconnection issues and policies related to reactive power management are in this paper.


Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 941 ◽  
Author(s):  
Xiaoling Xiong ◽  
Yuchen Yang

Due to the exhaustion of fossil energy, the utilization of renewable energy resources is developing quickly. Due to the intermittent nature of the renewable energy resources, the energy storage devices are usually adopted in renewable power generation system to enhance the system reliability. In this paper, the photovoltaic-based DC microgrid (PVDCM) system is designed, which is composed of a solar power system and a battery connected to the common bus via a boost converter and a bidirectional buck/boost converter, respectively. As the photovoltaic (PV) panels might operate in a maximum power point tracking (MPPT) mode or constant voltage mode, meanwhile, the power can flow between the battery and the load bidirectionally. Therefore, for the sake of optimizing power utilization in the PVDCM system, a control strategy making the system able to switch from one operating mode to another smoothly and automatically is proposed in this paper. Moreover, the small-signal modeling method based on averaged state-space is no more applicable in this study, thus the nonlinear analysis method with discrete-time mapping model is adopted for stability analysis. Based on the stability analysis, the closed-loop parameters are designed to make sure the whole system can operate properly in all operating modes. The control strategy and stability analysis based on the nonlinear analysis method in the closed-loop design are verified by experiment results.


2019 ◽  
Vol 10 (12) ◽  
pp. 1165-1171
Author(s):  
Karl Gatterer ◽  
◽  
Salah Arafa ◽  

Reliable and affordable energy is the key for the socio-economic development in rural and desert communities worldwide. While energy can be used for consumption purposes such as Lighting, Access to Information, Comfort and Entertainment, productive use of renewable energy is the key enabler for SMEs and Economy to grow. The paper examines the complex interactions among Energy, Materials, Water, Food, Building, Employment and Environment. It also discusses the implementation of renewable energy technologies to overcome some of barriers faced by rural villages and desert communities. It shows some of the special applications and approaches used over the past few decades in energy conversion, consumption and conservation to achieve poverty reduction, social justice and sustainable development. Field experiences in Basaisa projects, Egypt showed that open free dialogues with all stakeholders, site-specific education and training, appropriate local financing systems and access to knowledge are key-elements and essential factors for achieving green economy and sustainable community development. The coming decade will see a continued expansion of knowledge about renewable energy resources and its useful applications as systems friendly to the environment and as tools for economic activities, sustainable living and growth in rural and desert communities.


2012 ◽  
Vol 2 (11) ◽  
pp. 121-124
Author(s):  
Savitha C Savitha C ◽  
◽  
Dr. S. Mahendrakumar Dr. S. Mahendrakumar

Author(s):  
S. G. Obukhov ◽  
I. A. Plotnikov ◽  
V. G. Masolov

The paper presents the results of the comparative analysis of operation modes of an autonomous hybrid power complex with/without the energy store. We offere the technique which defines the power characteristics of the main components of a hybrid power complex: the consumers of the electric power, wind power and photo-electric installations (the last ones have been constructed). The paper establishes that, in order to compensate the seasonal fluctuations of power in autonomous power systems with renewable energy resources, the accumulative devices are required, with a capacity of tens of MWh including devices that are capable to provide energy storage with duration about half a year. This allows abandoning the storage devices for smoothing the seasonal fluctuations in the energy balance.The analysis of operation modes of energy stores has shown that for a stock and delivery of energy on time intervals, lasting several hours, the accumulative devices with rather high values of charging and digit power aren't required. It allows using the lead-acid rechargeable batteries of the deep category for smoothing the daily peaks of surplus and a capacity shortage. Moreover, the analysis of operation modes of energy stores as a part of the hybrid complexes has demonstrated that in charging/digit currents of the energy store the low-frequency and high-frequency pulsations of big amplitude caused by changes of size of output power of the renewable power installations and loading are inevitable. If low-frequency pulsations (the period of tens of minutes) can partially be damped due to the restriction of size of the maximum charging current of rechargeable batteries, then it is essentially impossible to eliminate high-frequency pulsations (the period of tens of seconds) in the power systems with the only store of energy. The paper finds out that the combined energy store having characteristics of the accumulator in the modes of receiving and delivery of power on daily time intervals, and at the same time having properties of the supercondenser in the modes of reception and return of impulses of power on second intervals of time is best suited to requirements of the autonomous power complexes with renewable energy resources.


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