1,721,014 research outputs found
Battery energy storage system for primary control reserve and energy arbitrage
No full textThe transition to high penetration of renewable energy sources brings about problems related to the security and reliability of the electric power system. For this reason, EU countries are considering extending participation in the provision of ancillary services to distributed generators. Grid-connected Battery Energy Storage Systems (BESS) are a promising technology for enabling this transition. Besides the research efforts to regulate and integrate BESS into the existing power systems, several studies have introduced improvements in BESS control for ancillary services provision. In this paper, attention is focused on primary control reserve (PCR). An introduction to the suitability of using BESS for PCR is followed by a literature review on BESS control strategies and controller models. Then the paper presents a model to investigate methods to increase BESS potential in providing PCR. The model is based on two different operating options: (i) variable-droop, meaning the droop-control is allowed to vary in time in order to avoid state of charge saturations and guarantee PCR availability; (ii) energy arbitrage, meaning that the battery is charged and discharged when economically favourable. A 1MW/1MWh BESS was simulated in MATLAB® Simulink® by implementing the two operating options via two fuzzy logic controllers that determine the droop and the arbitrage set points. The simulations rely on real metred data inputs (i.e. frequency and electricity prices) and demonstrate that both options improve BESS operations. Specifically, a study on the Italian case was applied to evaluate the feasibility of these applications in a real life scenario
Novel procedure to formulate load profiles for off-grid rural areas
Full text linkIn this paper, we describe the development, implementation and application of a novel mathematical procedure devoted to formulating the daily load profiles of off-grid consumers in rural areas. The procedure aims at providing such profiles as input data for the design process of off-grid systems for rural electrification. Indeed, daily load profiles represent an essential input for off-grid systems capacity planning methods based on steady-state energy simulation and lifetime techno-economic analyses, and for the analysis of the logics to control the energy fluxes among the different system components. Nevertheless, no particular attention has been devoted so far in the scientific literature as regards specific approaches for daily load profiles estimates for rural consumers. In order to contribute to covering this gap, we developed a new mathematical procedure taking into consideration the specific features of rural areas. The procedure is based on a set of data that can be surveyed and/or assumed in rural areas, and it relies on a stochastic bottom-up approach with correlations between the different load profile parameters (i.e. load factor, coincidence factor and number of consumers) in order to build up the coincidence behavior of the electrical appliances. We have implemented the procedure in a software tool (LoadProGen) which can eventually support the off-grid systems design process for rural electrification. Finally, we have applied the procedure to a case study in order to clarify the proposed approach
Community pico and micro hydropower for rural electrification: experiences from the mountain regions of Cameroon
Full text linkLess than 15% of rural areas of Cameroon have access to grid electricity. Only 53% of the population has access to grid electricity. Notwithstanding, Cameroon has a huge hydropower potential which could be harnessed. Mini grids, powered by pico and micro hydropower plants, are a relatively new rural electrification strategy in Cameroon. Several of such mini grids have been realized in the mountain regions of the country. Some of these systems have been more successful than others. This paper aims to share the experiences of community-based pico and micro hydropower schemes for rural electrification in Cameroon. The paper provides insight to the challenges that three of such mini grid systems powered by pico and micro hydropower plants had encountered and it attempts to identify issues related to their performances. The study was based on personal experience, field visits, participant observations, interviews and focus group discussions with key members of the beneficiary communities and documentations from the local NGO which implemented the schemes. Key findings of this study relate to the description of the main aspects about: planning of a robust system design, organizational aspects, like social cohesion at all levels of scheme management, community leadership and ownership of the system and involvement of the beneficiaries at all stages of the project cycle. These aspects were particularly addressed within the context of rural communities in Cameroon
Facts and Figure a Reasoned Approach
No full textIl capitolo affronta il tema dell'accesso all'energia con particolare riferimento alla situazione in Africa dove si identifica la dimensione del problema come al 2012
A sizing methodology based on Levelized Cost of Supplied and Lost Energy for off-grid rural electrification systems
Full text linkA methodology for supporting the planning of microgrids based on composable tools: A case in Bhutan
Full text linkElectrification Processes in Developing Countries: Grid Expansion, Microgrids, and Regulatory Framework
Full text linkShortages and poor diversification of generating
capacity, high environmental impacts, and low qualities of supply
and affordability are common characteristics of the electricity
sector in most developing countries (DevCs). Recent cost
reductions in the telecommunication sector and some generation
technologies, especially renewable-based, with improved
economic feasibility have paved the way for new electric
infrastructures. This is especially true for emerging economies,
as locally dispatched hybridmicrogrids introduce flexibility and
show the promise of technical and economic advantages. The
design and integration of microgrids require detailed assessments
to ensure the effective deployment of capital to minimize
the risk of stranded assets and capital waste. Microgrids
can be considered an affordable option for a rapid response
to the electrification challenge, recognizing that, in the longer
horizon, a sharing of resources with the bulk electrical power
system will remain, technically and economically, advantageous.
This article presents a comprehensive review of the
approaches commonly adopted for microgrid electrification.
A “real-life” study case is reported to highlight the operational
challenges of a stand-alone microgrid versus a grid-connected
system. The need for an improved regulatory framework is
presented as the cornerstone problem to be solved to allow
an effective integration of microgrids in the national grid
A Methodology To Develop Design Support Tools For Stand-Alone Photovoltaic Systems In Developing Countries
No full textOff-grid systems for rural electrification in developing countries: Definitions, classification and a comprehensive literature review
Full text linkAccess to electric power supply has always had a significant role in promoting improvements in all the society sectors, nevertheless nowadays 1.3 billion of people still do not have electricity access. Moreover, most of them live in rural areas of developing countries which are often isolated, scattered populated and characterized by poor infrastructure and services. In this situation, the growing consideration towards the target of universal access to energy has emphasized the role of rural electrification, and off-grid small-scale generation represents one of the most appropriate options. As a consequence, the scientific literature has devoted attention to this topic with a large number of papers. In this frame, the present analysis focuses on off-grid systems for rural electrification and provides a general framework to this topic and an analytical review of the literature. The work is based on the review of more than 350 papers mainly published from 2000 to 2014 within selected journals, and it is organized in two sections. In the first one we describe the role of small-scale generation systems throughout the process of electrification, the main features of rural areas and their typical energy uses, and we propose a new comprehensive taxonomy for off-grid systems for rural electrification. In the second one we develop an extensive review of the selected literature according to the proposed classification and to five main research areas: Technology: layout and components; Models and methods for simulation and sizing; Techno-economic feasibility analyses and sustainability analyses; Case studies analyses; Policy analyses. The work results in a comprehensive review which organizes and capitalizes the main fundamentals of the addressed topic and provides elements to get acquainted with the literature
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