Performance Assessment of Micro and Small-Scale Wind Turbines in Urban Areas

2012 ◽  
Vol 6 (1) ◽  
pp. 152-163 ◽  
Author(s):  
J. L. Acosta ◽  
K. Combe ◽  
Sasa Z. Djokic ◽  
I. Hernando-Gil
Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 35 ◽  
Author(s):  
Francesco Castellani ◽  
Davide Astolfi ◽  
Mauro Peppoloni ◽  
Francesco Natili ◽  
Daniele Buttà ◽  
...  

In the recent years, distributed energy production has been one of the main research topics about renewable energies. The decentralization of electric production from wind resources raises the issues of reducing the size of generators, from the MW scale of industrial wind farm turbines to the kW scale, and possibly employing them in urban areas, where the wind flow is complex and extremely turbulent because of the presence of buildings and obstacles. On these grounds, the use of small-scale vertical axis small wind turbines (VASWT) is a valid choice for on-site generation (OSG), considering their low sensitivity with respect to turbulent flow and that there is no need to align the turbine with wind direction, as occurs with horizontal axis small wind turbines (HASWT). In addition, VASWTs have a minor acoustic impact with respect to HASWTs. The aim of this paper is to study the interactions that take place between a 1.2 kW, vertical axis, Darrieus VASWT turbine and a small, experimental building, in order to analyze the noise and the vibrations transmitted to the structure. One method to damp the vibrations is then assessed through spectral analysis of data acquired through accelerometers located both in the mast of the wind turbine and at the building walls. The results confirm the usefulness of dampers to increase the building comfort regarding vibrations.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 139-144 ◽  
Author(s):  
S. Iwai ◽  
Y. Oshino ◽  
T. Tsukada

Although the ratio of sewer systems to population in Japan has been improving in recent years, the construction of sewer systems in small communities such as farming or fishing villages, etc. had lagged behind that of urban areas. However, construction of small-scale sewer systems in farming and fishing villages has been actively carried out in recent years. This report explains the history of the promotion of small-scale sewer systems, why submerged filter beds are being employed in many cases, and introduces the design, operation and maintenance of representative waste-water treatment plants in farming and fishing villages which incorporate de-nitrogen and dephosphorization.


2020 ◽  
Vol 37 ◽  
pp. 63-71
Author(s):  
Yui-Chuin Shiah ◽  
Chia Hsiang Chang ◽  
Yu-Jen Chen ◽  
Ankam Vinod Kumar Reddy

ABSTRACT Generally, the environmental wind speeds in urban areas are relatively low due to clustered buildings. At low wind speeds, an aerodynamic stall occurs near the blade roots of a horizontal axis wind turbine (HAWT), leading to decay of the power coefficient. The research targets to design canards with optimal parameters for a small-scale HAWT system operated at variable rotational speeds. The design was to enhance the performance by delaying the aerodynamic stall near blade roots of the HAWT to be operated at low wind speeds. For the optimal design of canards, flow fields of the sample blades with and without canards were both simulated and compared with the experimental data. With the verification of our simulations, Taguchi analyses were performed to seek the optimum parameters of canards. This study revealed that the peak performance of the optimized canard system operated at 540 rpm might be improved by ∼35%.


Author(s):  
Biagio Citarella ◽  
Rita Mastrullo ◽  
Alfonso W. Mauro ◽  
Massimiliano Sfragara ◽  
Marcello Tammaro

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.


2020 ◽  
Vol 29 (5) ◽  
pp. 74-88
Author(s):  
Aleksandr Larichev ◽  
Emil Markwart

Local government as a political, legal and social institution finds itself in a very difficult period of development in Russia. The long-established tendency of its subordination to the state has intensified today in connection with the newly adopted constitutional amendments. At the same time, it seems obvious that further “embedding” of local government into the state management vertical, in the absence of any positive effect in terms of solving socio-economic and infrastructural problems, will inevitably lead to other hard to reverse, negative results both for local government institutions and the system of public authority as a whole. The normal functioning of local government requires, however, not only the presence of its sufficient institutional and functional autonomy from the state, but also an adequate territorial and social base for its implementation. To ensure the formation of viable territorial collectives, especially in urban areas, it seems appropriate to promote the development of self-government based on local groups at the intra-municipal level. Such local groups can independently manage issues of local importance on a small scale (landscaping, social volunteering, and neighborly mutual assistance), and provide, within the boundaries of a local territory, due civil control over the maintenance by municipal authorities of more complex and large-scale local issues (repair and development of infrastructure, removal of solid household waste and more). At the same time, the development of local communities can by no means be a self-sufficient and substitutional mechanism, whose introduction would end the need for democracy in the full scope of municipal structures overall. In this regard, the experience of local communities’ development in Germany, a state with legal traditions similar to Russian ones, with a centuries-old history of the development of territorial communities and a difficult path to building democracy and forming civil society, seems to be very interesting. Here, the progressive development of local forms of democracy and the participation of residents in local issue management are combined with stable mechanisms of municipal government, and the interaction of municipalities with the state does not torpedo the existing citizen forms of self-government. At the same time, the experience of Germany shows that the decentralization of public issue management which involves the local population can only be effective in a situation where, in addition to maintaining a full-fledged self-government mechanism at the general municipal level, relevant local communities are endowed with real competence and resources to influence local issue decision-making. The role of formalized local communities in urban areas, as the German experience shows, can not only facilitate the decentralization of solving public problems, but can also help in timely elimination of triggers for mobilizing citywide supercollectives with negative agendas. This experience seems useful and applicable in the Russian context.


2005 ◽  
Vol 51 (12) ◽  
pp. 191-199 ◽  
Author(s):  
R. Craggs ◽  
L. Golding ◽  
S. Clearwater ◽  
L. Susarla ◽  
W. Donovan

Chironomid midge larvae are a valuable component of wastewater stabilisation pond (WSP) ecology. However, in high numbers, adult midge swarms can be a nuisance to near-by urban areas. Improving WSP treatment by incorporating aerobic or maturation ponds or by the addition of pre-treatment to reduce organic loading also increases the availability of aerobic sediment (midge larva habitat) in the pond system and the potential for midge nuisance problems. The efficacy of Maldison, an organophosphate traditionally used to control midge larvae in New Zealand WSPs, was compared to Bacillus thuringiensis var. israelensis (Bti), Methoprene, Pyriproxyfen and Diflubenzuron which are all more specific to insects and have fewer adverse environmental effects. Initial laboratory trials established the concentration of each compound required to achieve 95% control of the midge population. During 21-day small-scale trials within the WSP, Bti, Diflubenzuron and Maldison reduced live larvae numbers substantially (80–89%) compared to controls and adult midge emergence was markedly reduced by all compounds (72–96%). Large-scale trials with Bti (Vectobac® WG) powder (1000 μg/L) only caused a slight reduction in midge larvae numbers compared to controls and had little effect on adult emergence, however, Methoprene (Prolink XRG granules) (50 μgAI/L) reduced midge adult emergence by ∼80% over 25 days and has been used successfully to control several midge nuisance outbreaks.


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