Experimental and CFD investigation of small-scale solar chimney for power generation. Case study: southeast of Algeria

2019 ◽  
Vol 160 ◽  
pp. 1-8
Author(s):  
A. Azizi ◽  
T. Tahri ◽  
M.H. Sellami ◽  
L. Segni ◽  
R. Belakroum ◽  
...  
Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5874
Author(s):  
Navid Goudarzi ◽  
Kasra Mohammadi ◽  
Alexandra St. St. Pé ◽  
Ruben Delgado ◽  
Weidong Zhu

Annual mean wind speed distribution models for power generation based on regional wind resource maps are limited by spatial and temporal resolutions. These models, in general, do not consider the impact of local terrain and atmospheric circulations. In this study, long-term five-year wind data at three sites on the North, East, and West of the Baltimore metropolitan area, Maryland, USA are statistically analyzed. The Weibull probability density function was defined based on the observatory data. Despite seasonal and spatial variability in the wind resource, the annual mean wind speed for all sites is around 3 m/s, suggesting the region is not suitable for large-scale power generation. However, it does display a wind power capacity that might allow for non-grid connected small-scale wind turbine applications. Technical and economic performance evaluations of more than 150 conventional small-scale wind turbines showed that an annual capacity factor and electricity production of 11% and 1990 kWh, respectively, are achievable. It results in a payback period of 13 years. Government incentives can improve the economic feasibility and attractiveness of investments in small wind turbines. To reduce the payback period lower than 10 years, modern/unconventional wind harvesting technologies are found to be an appealing option in this region. Key contributions of this work are (1) highlighting the need for studying the urban physics rather than just the regional wind resource maps for wind development projects in the build-environment, (2) illustrating the implementation of this approach in a real case study of Maryland, and (3) utilizing techno-economic data to determine suitable wind harnessing solutions for the studied sites.


2018 ◽  
Vol 61 ◽  
pp. 00011
Author(s):  
Archishman Bose ◽  
Kiran Raj ◽  
Denitsa Kuzeva ◽  
Tommaso Mura ◽  
Jialei Xin ◽  
...  

Decentralized power generation, from renewables, is an attractive option for the future energy transition. Through a case study, the techno-economic feasibility to produce own power from distributed renewable to de-carbonize the operations of the Small and Medium Scale Enterprises (SMEs) was critically analysed. The case study was performed on one of the leading printing outfits of Sri Lanka. Solar photovoltaic (PV) and biomass gasification systems are the most cost-efficient and easy to operate technologies for grid-connected, small-scale power generation, at present, for the context. Grid integration has been found as a major challenge, in both technical and economic parameters of the project. The low capacity factor of solar PV and complexity of the supply chain for biomass power systems are critical to the respective technologies. A hybrid Solar PV-Biomass gasification power plant would have superior techno-economic performances with lower environmental impact than stand-alone systems. An equal share of the net power capacity between the technologies was obtained as the most suitable combination for the proposed hybrid power plant. A net carbon dioxide reduction of more than eighty percent of the operations of the SMEs is feasible. Socio-political factors also have a high impact on overall viability of such small-scale systems.


Author(s):  
Suchart Janjornmanit ◽  
Sakorn Panta ◽  
Vishnu Thonglek

The controls of power generation by the inverter-based generator are proposed in this work. The proposed control adjusts the active power output by varying the phase angle instead of the conventional frequency variation. The benefit of operating the network by a fixed frequency is that it eradicates the problems associated with the frequency deviation. The PID controls with recommended gain adjustment are proposed to control the power generation. The power generation schemes are adapted from the classical power generation by the synchronous generator, where the modes of operation are Swing, PV and PQ mode. The proposed three modes of operation are adequate to operate fully in a small-scale power system such as in an islanded microgrid. A case study of operating the proposed controls in a microgrid by simulation is used to demonstrate the feasibility of implementation of the controls.


2021 ◽  
pp. 136700692110231
Author(s):  
Francesca Romana Moro

Aims and Objectives/Purpose/Research Questions: The Alorese in eastern Indonesia are an Austronesian community who have inhabited two Papuan-speaking islands for approximately 600 years. Their language presents a paradox: contact with the neighbouring Papuan languages has led to both complexification and simplification. This article argues that these opposite outcomes of contact result from two distinct scenarios, and formulates a hypothesis about a shift in multilingual patterns in Alorese history. Design/Methodology/Approach: To formulate a hypothesis about the discontinuity of multilingual patterns, this article first sketches the past and present multilingual patterns of the Alorese by modelling language contact outcomes in terms of bilingual optimisation strategies. This is followed by a comparison of the two scenarios to pinpoint similarities and differences. Data and Analysis: Previous research shows that two types of contact phenomena are attested in Alorese: (a) complexification arising from grammatical borrowings from Papuan languages, and (b) morphological simplification. The first change is associated with prolonged child bilingualism and is the result of Papuan-oriented bilingual strategies, while the latter change is associated with adult second language (L2) learning and is the result of universal communicative strategies. Findings/Conclusions Complexification and simplification are the results of two different layers of contact. Alorese was first used in small-scale bilingual communities, with widespread symmetric multilingualism. Later, multilingualism became more asymmetric, and the language started to undergo a simplification process due to the considerable number of L2 speakers. Originality: This article is innovative in providing a clear case study showing discontinuity of multilingual patterns, supported by linguistic and non-linguistic evidence. Significance/Implications: This article provides a plausible explanation for the apparent paradox found in Alorese, by showing that different outcomes of contact in the same language are due to different patterns of acquisition and socialisation. This discontinuity should be taken into account by models of language contact.


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