Monitoring moisture and inorganic content of forest harvesting residues for energy production purposes: A case study

2020 ◽  
Vol 61 (1) ◽  
pp. 8.01-8.12
Author(s):  
Mahdi Vaezi ◽  
◽  
Md Ruhul Kabir ◽  
Amit Kumar ◽  
◽  
...  
Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4618
Author(s):  
Antonio Mariani ◽  
Gaetano Crispino ◽  
Pasquale Contestabile ◽  
Furio Cascetta ◽  
Corrado Gisonni ◽  
...  

Overtopping-type wave power conversion devices represent one of the most promising technology to combine reliability and competitively priced electricity supplies from waves. While satisfactory hydraulic and structural performance have been achieved, the selection of the hydraulic turbines and their regulation is a complex process due to the very low head and a variable flow rate in the overtopping breakwater set-ups. Based on the experience acquired on the first Overtopping BReakwater for Energy Conversion (OBREC) prototype, operating since 2016, an activity has been carried out to select the most appropriate turbine dimension and control strategy for such applications. An example of this multivariable approach is provided and illustrated through a case study in the San Antonio Port, along the central coast of Chile. In this site the deployment of a breakwater equipped with OBREC modules is specifically investigated. Axial-flow turbines of different runner diameter are compared, proposing the optimal ramp height and turbine control strategy for maximizing system energy production. The energy production ranges from 20.5 MWh/y for the smallest runner diameter to a maximum of 34.8 MWh/y for the largest runner diameter.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4271
Author(s):  
Lucia Cattani ◽  
Paolo Cattani ◽  
Anna Magrini

Photovoltaic panel efficiency can be heavily affected by soiling, due to dust and other airborne particles, which can determine up to 50% of energy production loss. Generally, it is possible to reduce that impact by means of periodic cleaning, and one of the most efficient cleaning solutions is the use of demineralized water. As pauperization of traditional water sources is increasing, new technologies have been developed to obtain the needed water amount. Water extracted from the air using air to water generator (AWG) technology appears to be particularly suitable for panel cleaning, but its effective employment presents issues related to model selection, determining system size, and energy efficiency. To overcome such issues, the authors proposed a method to choose an AWG system for panel cleaning and to determine its size accordingly, based on a cleaning time optimization procedure and tailored to AWG peculiarities, with an aim to maximize energy production. In order to determine the energy loss due to soiling, a simplified semiempirical model (i.e., the DIrt method) was developed as well. The methodology, which also allows for energy saving due to an optimal cleaning frequency, was applied to a case study. The results show that the choice of the most suitable AWG model could prevent 83% of energy loss related to soling. These methods are the first example of a design tool for panel cleaning planning involving AWG technology.


1991 ◽  
Vol 32 (5) ◽  
pp. 505-513
Author(s):  
A.M. Tayeb ◽  
H.M. Asfour ◽  
I.H. Aly ◽  
N.A. Mostafa

Energy ◽  
2021 ◽  
Vol 222 ◽  
pp. 119972
Author(s):  
I. Iglesias ◽  
A. Bio ◽  
L. Bastos ◽  
P. Avilez-Valente

2018 ◽  
Vol 3 (2) ◽  
pp. 667-680 ◽  
Author(s):  
Jennie Molinder ◽  
Heiner Körnich ◽  
Esbjörn Olsson ◽  
Hans Bergström ◽  
Anna Sjöblom

Abstract. The problem of icing on wind turbines in cold climates is addressed using probabilistic forecasting to improve next-day forecasts of icing and related production losses. A case study of probabilistic forecasts was generated for a 2-week period. Uncertainties in initial and boundary conditions are represented with an ensemble forecasting system, while uncertainties in the spatial representation are included with a neighbourhood method. Using probabilistic forecasting instead of one single forecast was shown to improve the forecast skill of the ice-related production loss forecasts and hence the icing forecasts. The spread of the multiple forecasts can be used as an estimate of the forecast uncertainty and of the likelihood for icing and severe production losses. Best results, both in terms of forecast skill and forecasted uncertainty, were achieved using both the ensemble forecast and the neighbourhood method combined. This demonstrates that the application of probabilistic forecasting for wind power in cold climates can be valuable when planning next-day energy production, in the usage of de-icing systems and for site safety.


2017 ◽  
Author(s):  
Jennie P. Söderman ◽  
Heiner Körnich ◽  
Esbjörn Olsson ◽  
Hans Bergström ◽  
Anna Sjöblom

Abstract. The problem of icing on wind turbines in cold climates is addressed using probabilistic forecasting to improve next- day forecasts of icing and related production losses. A case study of probabilistic forecasts was generated for a two- week period. Uncertainties in initial and boundary conditions are represented with an ensemble forecasting system, while uncertainties in the spatial representation are included with a neighbourhood method. Using probabilistic forecasting instead of one single forecast was shown to improve the forecast skill of the ice-related production loss forecasts and hence the icing forecasts. The spread of the multiple forecasts can be used as an estimate of the forecast uncertainty and of the likelihood for icing and severe production losses. Best results, both in terms of forecast skill and forecasted uncertainty, were achieved using both the ensemble forecast and the neighbourhood method combined. This demonstrates that the application of probabilistic forecasting for wind power in cold climate can be valuable when planning next-day energy production, in the usage of de-icing systems, and for site safety.


2021 ◽  
Author(s):  
◽  
Singkham Lueyeevang

<p>Over the last decade, construction of hydropower dams has increased rapidly around the world, including in developing countries. For many countries including Laos, energy production and export play a significant role in promoting and boosting economic growth and development. Energy production generates substantial revenue and foreign exchange from exporting electricity and expands economic activity domestically. However, construction of hydropower dams also causes negative effects on the people who live at and around the dam site. Some local communities have been affected indirectly, while others require relocation to other areas bringing significant change, including for women. This research explores the impact of resettlement from hydropower dam creation on women by using the Nam Mang 3 hydropower dam in central Laos as a case study. This dam, completed in 2005, required the relocation of approximately 150 households from two villages at the dam site. The research draws on a social constructivist epistemology, qualitative methods including semi-structured interviews, and analysis of relevant policy documents. Interviews involved 18 participants including both male and female from the three affected villages. Results indicate that the resettlement of villagers by the Nam Mang 3 hydropower dam has generally improved living conditions of the resettled communities. Women were found to have greater opportunities to benefit from home-based business, employment and wage labouring. In addition, with better access to modern facilities and services, women have been able to save greater time from agricultural activities and divert this time saving to other economic activities. Overall, access to water supplies, roads, and transport have reduced women’s workload significantly. Access to improved health services and facilities have also improved women’s wellbeing. Girls have greater opportunities to attend school and seek employment in towns. However, this research identified some challenges experienced by the resettled such as the reduction of agricultural and grazing land area, and that new livelihood options were not accessible to all women. Instead of these challenges, the experience with the Nam Mang 3 hydropower project has highlighted one of the key lessons learnt that is worth highlighting for future resettlement programs, which is to have the resettlers fully engaged in the entire process of resettlement and livelihood strategy development.</p>


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