Seen and not heard: Students’ uses and experiences of silence in school relationships at a secondary school

Silence is traditionally understood as a power deficit; yet, it creates spaces in which power works unobtrusively. In this article, I report the findings of a qualitative study examining silence in school relationships. Based on nine conceptual discussions and 33 interviews with teachers and students in a secondary school in the UK, I assert that uses of silence in relationships between students and teachers revolve around two conceptions of power: a stronghold of respect and a refuge for dignity.

A Solution to Prevent a Blackout Crisis: Determining the Behavioral Potential and Capacity of Solar Power

Increasing the power grid peak in the summer time causes power outages in industries and residential areas in Iran. The most obvious example of this issue is the power outages in the summer of 2018. Management of the demand-side is the most important strategy to reduce the grid peak due to the high cost of the development of the power plant capacity (500$ per kilowatt). In the present study, the effect of behavioral parameters in decreasing the power grid peak was identified. The behavioral simulation was done as an agent-based model using the raw data of the time-use survey (TUS) of the Statistics Center of Iran. 4228 urban households were surveyed, and the quality of people’s behavior was determined in each time step of 15 minutes during the day and night with 2 deterministic and stochastic approaches. In the stochastic approach, the Markov chain method was used. It showed that the power grid peak can only be reduced by 10% with behavioral flexibility and up to 25% by upgrading technology. In addition, based on the power deficit in 2018, 2000 megawatts of solar power capacity must be added to the network at peak times to meet grid demand.

AN OVERVIEW OF THE COMPOSITE DESIGN OF SMART GRID DUE TO POWER DEMAND,PRODUCTION AND POWER DEFICIT IN NIGERIA

The general aim and objectives of the research is to demonstrate an overview of the composite design and emphasis of the implementation of an effective and efficient smart grid power system that will address the challenges of epileptic power due to power demand, power production and power deficit in Nigeria.

Total power deficiency estimation of isolated power system network using full-state observer method

<span>An isolated electrical network with an independent local distributed generator is very sensitive towards the contingencies between load demand and supply. Although the network system has less complexity in term of structure, its stability condition is crucial due to its stand-alone operating condition. The total power deficit in the network gives the important information related to the dynamical frequency responses which may directly affect the system’s stability level. In this paper, the approach to estimate the total power deficiency for the isolated electrical network was presented by utilized the Luenberger observer method. Although the power deficit is not the state variable in the network mathematical model, the solution of estimation problem was feasible by introducing the new variable using additional dummy system. The simulation was carried out by using MATLAB/Simulink environment and the designed estimator was verified using multifarious load demand changes. The results show that the estimated signal was successfully tracked the expected actual signal with minimum error.</span>

Improved Evaluation of The Wind Power Potential of a Large Offshore Wind Farm Using Four Analytical Wake Models

The objective of this paper is to investigate the ability of analytical wake models to estimate the wake effects between wind turbines (WTs). The interaction of multiple wakes reduces the total power output produced by a large offshore wind farm (LOFWF). This power loss is due to the effect of turbine spacing (WTS), if the WTs are too close, the power loss is very significant. Therefore, the optimization of turbine positions within the offshore wind farm requires an understanding of the interaction of wakes inside the wind farm. To better understand the wake effect, the Horns Rev 1 offshore wind farm has been studied with four wake models, Jensen, Larsen, Ishihara, and Frandsen. A comparative study of the wake models has been performed in several situations and configurations, single and multiple wakes are taken into consideration. Results from the Horns Rev1 offshore wind farm case have been evaluated and compared to observational data, and also with the previous studies. The power output of a row of WTs is sensitive to the wind direction. For example, if a row of ten turbines is aligned with the 270° wind direction, the full wake condition of WTs is reached and the power deficit limit predicted by Jensen model exceeds 70%. When a wind direction changes only of 10° (260° and 280°), the deficit limit reduces to 30%. The obtained results show that a significant power deficit occurs when the turbines are arranged in an aligned manner. The findings also showed that all four models gave acceptable predictions of the total power output. The comparison between the calculated and reported power output of Horns Revs 1 showed that the differences ranged from - 8.27 MW (12.49%) to 15.27 MW (23.06%) for the Larsen and Frandsen models, respectively.

Hydropower potential in Assam: Assessment and analysis

Electricity is a must in every aspect of life. It has been identified as a fundamental human desire. It is the foundation of a country’s socio-economic growth. The provision of low-cost electricity to rural India is critical to the country’s overall growth. The service sector has made a significant contribution to our economy’s development. The availability of a high-quality electricity supply is critical to the sector’s long-term development. Energy consumption is rapidly increasing, as are greenhouse gas emissions from the energy industry. In terms of socio-economic indicators, Assam lags behind the rest of India. The vast hydroelectric potential of the area is due to the abundance of seasonal rivers and water bodies. However, it has been observed that hydropower development is hampered by a number of factors, including technical difficulties, political problems, a lack of adequately investigated projects, environmental concerns, power evacuation issues and many more. Exploitation of the huge hydro potential in Assam could be used for export to the power deficit regions of the country. Construction of infrastructure in remote hilly areas, communications, and energy supply, will benefit the country as a whole, resulting in a higher standard of living. The study’s aim is to determine the current power situation in Assam in terms of hydropower and also highlighting the region’s hydropower sector’s potential opportunities and challenges.

Offshore Wind Energy Integration using Photovoltaic Systems and Batteries as Smoothing Devices

Currently, producing electrical energy is among the major concerns, which will continue to grow in the future. This is due, on the one hand, to the depletion and high conventional energy sources costs. On the other hand, because of the pollution they cause to the environment, hence the need to produce electrical energy from renewable and clean sources, such as wind, photovoltaic and tidal systems. The exploitation of the sea wind by offshore wind turbines is interesting and promising. In this context, this work aims to propose a new approach to hybrid offshore wind/photovoltaic/battery systems energy management. The power produced by the photovoltaic/battery will be used to compensate for the lack of power presented by offshore wind production in relation to the demand of the grid, as offshore wind is taken as a main source in this study. To achieve the set objective, an energy management algorithm is developed and implemented. This algorithm makes it possible to involve photovoltaics in the first place, in a progressive way according to the power deficit presented by the offshore park and the available sunshine. As it also aims to manage the charge and discharge of the battery bench last if the power supplied by the offshore wind farm alone or by offshore wind/photovoltaic does not match the demand. To verify the efficiency of this management algorithm, simulations of the offshore wind/photovoltaic/battery system were carried out under matlab/simpowers. This system is divided into several sub-systems: wind, photovoltaic and battery bank. Each of them is equipped with different specific infrastructure, as well as adequate control systems for proper operation. All subsystems are grouped together at a common connection point, where energy management is carried out prior to connection to the distribution network. The results obtained validated the main approaches of the proposed method allowing a reliable stabilization of the power level to the common connection point at the reference power that must be injected into the distribution network.

Study and Simulation of a Wind Hydro Isolated Microgrid

Isolated microgrids are microgrids which operate autonomously. This paper presents an isolated microgrid which combines a Hydraulic Turbine Generator (HTG) with a Wind Turbine Generator (WTG) to supply consumers forming a Wind Hydro Isolated Microgrid (WHIM). The WHIM includes a Dump Load (DL) to dissipate the active power excess. The WHIM has been modeled and its operation has been simulated in two modes: Wind-Hydro (WH), where both HTG and WTG supply power, and Wind-Only (WO) mode, where the WTG is the active power supplier and the HTG keeps connected to the grid with null power to generate the grid voltage. In WO, a fast frequency regulation is achieved by means of a controller which commands the DL to consume the WTG power excess. Additionally, the simulation of the mode transition from WO to WH, which is triggered by a system active power deficit in WO mode, is shown. A kick starting system designed to speed up the HTG power production improves the transient from WO to WH mode change. Finally, the simulations in WH mode show the interaction between the HTG and WTG. The two controls proposed have been proved effective and the simulations show a good WHIM dynamic performance.