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Articles 31 - 60 of 69

Full-Text Articles in Energy Systems

Economic Analysis Of Islanded Microgrid: A Case Study Of Kisiju Village - Coastal Region, Jackson Justo Feb 2022

Economic Analysis Of Islanded Microgrid: A Case Study Of Kisiju Village - Coastal Region, Jackson Justo

Tanzania Journal of Engineering and Technology (TJET)

The concept of Microgrid (MG) has gained significant attention of researchers and projects on the business side of electrical power generation and utilization, particularly in electrification of islanded areas such as villages. Most of these microgrids are powered by renewable energy resources (RERs) and they distribute power in low voltage distribution networks. Hence, these systems are faced with reliability problems due to the intermittency nature of RERs which affect the technical as well as the return on Investment of specific projects. In the latter context, reliability and economic analysis of the MG systems is an inevitable choice. This paper presents …


High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen Jan 2022

High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen

Advanced Science Research Center

Water-responsive (WR) materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. Here, it is presented that Bacillus (B.) subtilis’ peptidoglycan (PG) exhibits WR actuation energy and power densities reaching 72.6 MJ m−3 and 9.1 MW m−3, respectively, orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. PG can deform as much as 27.2% within 110 ms, and its actuation pressure reaches ≈354.6 MPa. Surprisingly, PG exhibits an energy conversion efficiency of ≈66.8%, which can be attributed to its super-viscous nanoconfined …


Assessment Of The Impacts Of Climate Variability On Hydropower Generation: A Case Study Of The New Pangani Falls, Tanzania, Dativa Byarufu Jul 2021

Assessment Of The Impacts Of Climate Variability On Hydropower Generation: A Case Study Of The New Pangani Falls, Tanzania, Dativa Byarufu

Tanzania Journal of Engineering and Technology (TJET)

Climate change poses potential impacts on hydropower generation either positively by increasing or negatively by decreasing river flow. This study assessed the impacts of climate variability on hydropower with a focus on the New Pangani Falls in Tanzania. Rainfall and temperature time series data from 1980-2014 were analyzed in relation to river discharge and associated impacts to hydropower generation. The Man-Kendall test was used to detect trend in both annual and seasonal time series. The results showed a negative trend in annual rainfall with Z= -2.41 at α = 0.05 and the slope Q = -0.964. Seasonal trend analysis showed …


Performance And Economics Of Solar Inverters And Module Level Power Electronics In A 1 Mw Photovoltaic System, Maxwell Criswell May 2021

Performance And Economics Of Solar Inverters And Module Level Power Electronics In A 1 Mw Photovoltaic System, Maxwell Criswell

Biological and Agricultural Engineering Undergraduate Honors Theses

Photovoltaic solar panels convert sunlight to electricity in the form of direct current; therefore, a necessary component of every photovoltaic system is an inverter to convert the electricity to usable alternating current. There are various commercially available inverter technologies manufactured today such as microinverters, string inverters, and central inverters, as well as module level power electronic devices such as DC optimizers that are capable of improving system performance in string and central inverter systems. This thesis compares the performance and economics of five different inverter and module level power electronic systems through model simulation using Helioscope software. The five alternatives …


Potential For Increased Rural Electrification Rate In Sub-Saharan Africa Using Swer Power Distribution Networks, Aviti Thadei Mushi Dec 2020

Potential For Increased Rural Electrification Rate In Sub-Saharan Africa Using Swer Power Distribution Networks, Aviti Thadei Mushi

Tanzania Journal of Engineering and Technology (TJET)

Rural electrification rate (RER) in Africa is still low to date. Several countries in Sub-Saharan Africa have tried to address this problem using conventional single phase two-wire or three-phase three-wire systems, however at large costs due to the nature of dispersed rural load centres, low load demand, and low population density. Another solution of off-grid generation creates associated health problems. Therefore, this paper undertakes a review of a single wire earth return (SWER) network as a RER improvement solution. The paper undertakes intensive literature review to elucidate challenges and solutions to the implementation of SWER technology. Advantages of SWER technology …


Wind Power Integration And Its Impact On Power Quality-A Didactic Approach, Santos Kihwele Dr Dec 2020

Wind Power Integration And Its Impact On Power Quality-A Didactic Approach, Santos Kihwele Dr

Tanzania Journal of Engineering and Technology (TJET)

This paper presents a model of a wind power system integrated with realistic power system, with intention of using it in addressing power quality issues in relations to grid codes during steady-state operation transient-state operation i.e., presence of grid fault events. For that case, a didactic approach of the normal performance of power systems due to the connection of fixed-speed wind turbine with induction generators is used. A study of integrating wind farms will be presented, including the incidence of high inrush current due to switching capacitor banks, out-rush current and voltage sags due to nearby three phase faults. As …


Experimental Investigation Of The Wind Energy Harvesting Potential Of A Stand-Alone Piezoelectric Strip, Phillip Christopher Scott Jul 2020

Experimental Investigation Of The Wind Energy Harvesting Potential Of A Stand-Alone Piezoelectric Strip, Phillip Christopher Scott

Mechanical Engineering ETDs

The purpose of the study was to investigate the feasibility of harvesting wind energy on a small scale in residential areas. The method investigated was the initiation of movement-induced excitation (MIE), a type of aeroelastic flutter, within samples of polyvinylidine fluoride (PVDF), a piezoelectric polymer. Single samples of PVDF were secured in a wind tunnel and sample voltage was measured over a broad range of wind speeds. Power was calculated then via the addition of ohmic resistance matched to the magnitude of the capacitive impedances of the samples. The geometry of the PVDF samples studied was maintained as a simple …


Performance Analysis Of Renewable Energy Resources In Rural Areas: A Case Study Of Solar Energy, Jackson Justo Jun 2020

Performance Analysis Of Renewable Energy Resources In Rural Areas: A Case Study Of Solar Energy, Jackson Justo

Tanzania Journal of Engineering and Technology (TJET)

This paper presents an overview of the recent development trends of solar photovoltaic (PV) systems and the performance in the Tanzanian context. The two types of solar power generation that are considered in this paper are: i) solar PV systems and ii) concentrated solar power (CSP). The two are compared in terms of cost of energy and energy storage mechanism. Moreover, the effect of ambient temperature on the solar PV module is analyzed. In addition, a detailed analysis on using solar axis tracking to increase the power generation is also presented. The extent to which the cell surface temperature and …


Modeling And Control Of Solar Pv With Battery Energy Storage For Rural Electrification, Irene Masenge Jun 2020

Modeling And Control Of Solar Pv With Battery Energy Storage For Rural Electrification, Irene Masenge

Tanzania Journal of Engineering and Technology (TJET)

In rural areas where electric power grid network is rarely available, power generation from renewable energy resource such as solar photovoltaic (PV) is mostly accomplished in standalone mode. The standalone solar PV system requires energy storage device to achieve reliable power supply to the end users. This paper presents modelling and coordination control of solar PV with battery energy storage system (BESS) for rural-electrification applications. The proposed control is accomplished via a bidirectional buck-boost converter with the objective of maintaining voltage at the DC bus constant. Simulation results based-on MATLAB/Simulink platform confirms good performance of the proposed system


Dartmouth Formula Racing: Full Electric Battery System Design, Matt Gardner, Jacob Hagler, Ruthie Nordhoff, Otto Salmi Mar 2020

Dartmouth Formula Racing: Full Electric Battery System Design, Matt Gardner, Jacob Hagler, Ruthie Nordhoff, Otto Salmi

ENGS 89/90 Reports

Dartmouth Formula Racing (DFR) lacked an electrical energy storage system that was Formula Hybrid rules-compliant, optimized for FH events, safe, reliable, and integrated with the rest of their vehicle. Additionally, the team lacked the academic and professional resources required to bring a thorough, analytical approach to the design, testing, and documentation of the new storage system. Our team designed and built a Lithium-Ion battery pack (accumulator) containing energy storage, active cooling, battery management and temperature monitoring systems, and control circuitry compatible with DFR’s vehicle. Collaboration throughout design, fabrication, assembly and testing processes ensured effective knowledge transfer to the DFR team.


Residential Thermal Storage And Cooling, Joao Marcelo Rocha Belmonte, Jacob Anderson, Andrew Clarke, Daphne Forester, Bianca Hardtke, Josh Hartman, Marc D. Compere Jan 2020

Residential Thermal Storage And Cooling, Joao Marcelo Rocha Belmonte, Jacob Anderson, Andrew Clarke, Daphne Forester, Bianca Hardtke, Josh Hartman, Marc D. Compere

Sustainability Conference

No abstract provided.


Dual-Axis Solar Tracker, Bryan Kennedy Jan 2020

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …


The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1 Dec 2019

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …


Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney Jul 2019

Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use a thermoelectric generator module to analyze the relationship between thermal and electrical energies. Using data collection sensors and analysis software, students will investigate the relationship between the temperature gradient across a thermoelectric generator module and the resulting electrical potential. Students will then use their data and analysis to solve problems relating to waste thermal energy in electrical systems and communicate their work to their peers and teacher.


The Comparative Analysis Of The Performances Of Four And Six Pole Pairs Permanent Magnet Synchronous Generator, Ra Msuya Jun 2019

The Comparative Analysis Of The Performances Of Four And Six Pole Pairs Permanent Magnet Synchronous Generator, Ra Msuya

Tanzania Journal of Engineering and Technology (TJET)

Wind power applications using multi-poles permanent magnet generators have become very attractive especially in small ratings. Low-speed multi-pole PM generators are maintenance-free and may be used in different climate conditions. Most of the low speed wind turbine generators presented is permanent magnet machines, which have advantages of high efficiency and reliability since there is no need of external excitation and conductor losses are removed from the rotor. From the study two types of PM AC generator are designed with 6 pole pairs and the other one with 4 pole pairs. These generators were designed and analysed using Maxwell software. The …


Networked Microgrid Optimization And Energy Management, Robert S. Jane Jan 2019

Networked Microgrid Optimization And Energy Management, Robert S. Jane

Dissertations, Master's Theses and Master's Reports

Military vehicles possess attributes consistent with a microgrid, containing electrical energy generation, storage, government furnished equipment (GFE), and the ability to share these capabilities via interconnection. Many military vehicles have significant energy storage capacity to satisfy silent watch requirements, making them particularly well-suited to share their energy storage capabilities with stationary microgrids for more efficient energy management. Further, the energy generation capacity and the fuel consumption rate of the vehicles are comparable to standard diesel generators, for certain scenarios, the use of the vehicles could result in more efficient operation. Energy management of a microgrid is an open area of …


Cost Benefit Analysis Of Led Vs Florescent Lighting, Kurtis Clark, Phillip Humphrey Nov 2018

Cost Benefit Analysis Of Led Vs Florescent Lighting, Kurtis Clark, Phillip Humphrey

Student Research

Over the last few years, the state of Oklahoma has been looking at ways to reduce expenses to address concerns about a budget deficit. There have been efforts made to reduce expenses due to the use of energy. It has been said, when the lights are on, work is getting done. Running lights is therefore the cost of doing business. Our research examines the question, “is there a way to provide better lighting while operating at a lower cost.” This research examines the current lighting at Southwestern State University, primarily fluorescent lighting (FL), and a cost benefit analysis of switching …


Low Voltage Ride Through Enhancement For Wind Turbines Equipped With Dfig Under Symmetrical Grid Faults, Francis Mwasilu Jun 2018

Low Voltage Ride Through Enhancement For Wind Turbines Equipped With Dfig Under Symmetrical Grid Faults, Francis Mwasilu

Tanzania Journal of Engineering and Technology (TJET)

In modern power systems with significant penetration of wind-turbines (WTs), improvement of low voltage ride through (LVRT) capability of WTs equipped with doubly-fed induction generators (DFIGs) is an important issue. Thus, this paper proposes a low voltage ride through (LVRT) strategy, which comprise of a capacitor connected in series with an inductor both connected in parallel to a resistor. The configuration is then connected to a small series resistor via a pair of antiparallel-Thyristors. The circuit and its switching control scheme of the proposed LVRT circuit are designed to: minimize the transition times, maintain the RSC connection to the rotor-windings, …


A Human Powered Micro-Generator For Charging Electronic Devices, John Adam May 2018

A Human Powered Micro-Generator For Charging Electronic Devices, John Adam

Senior Theses

A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour …


Optimal Operation Of Integrated Microgrids, Abdullah Albaker Jan 2018

Optimal Operation Of Integrated Microgrids, Abdullah Albaker

Electronic Theses and Dissertations

Microgrids' deployments are increasing and projected to increase even more in future due to the significant advantages that are provided by this technology for end-use customers. However, microgrids can be connected to each other to create integrated microgrids system, which can further promote the anticipated and desired benefits. An integrated operation of microgrids can potentially improve the local power system reliability and resilience, increase the individual microgrids' economic benefits, and promote further utilization of renewable energy resources. Integrating microgrids, to achieve a microgrid network or cluster, is expected be an essential application towards smarter power grids and a key operational …


Designing And Testing 3-D Printed Wafer-Box With Embedded Pzt Sensors To Identify The Shape Effect On Energy Harvesting, Ahmad Jami Safayet Jan 2018

Designing And Testing 3-D Printed Wafer-Box With Embedded Pzt Sensors To Identify The Shape Effect On Energy Harvesting, Ahmad Jami Safayet

College of Graduate Studies: Theses & Dissertations

Piezoelectric energy has been recently paid attention in the field of alternative energy. Day by day the traditional energy sources including Coal tar and oils are becoming scarce. People are heading to an alternative energy source to meet the future energy demand. Piezoelectric energy is one of the competitive energy sources compared to the conventional renewable energy sources including solar, wind, and geothermal power and so on. This energy production method bears enormous research potential because it can be used as the roadway for a new method of power generation. This research project aimed to identify which shaped wafer-box produced …


Solar Irradiance Forecasting And Implications For Domestic Electric Water Heating, Christopher Nutter Jan 2017

Solar Irradiance Forecasting And Implications For Domestic Electric Water Heating, Christopher Nutter

College of Graduate Studies: Theses & Dissertations

As the effects of burning fossil fuels continues to present its prevalence, the interests in alternative forms of energy is expanding. Within the home, the domestic electrical water heater accounts for approximately 17% of its energy consumption. Reducing the amount of energy required to produce hot water from this thermal system alone can have a significant effect on reducing its carbon footprint. In this presented work, a modeled domestic electrical water heater was supplied photovoltaic and on-grid electrical power to increase its energy efficiency. As photovoltaic (PV) energy is directly related to solar irradiation, it is important to receive accurate …


Using Photovoltaics To Power Electrochemical Chloride Extraction From Concrete, Sean Bond, Lynette O'Callaghan, Niall Holmes Dr., Brian Norton Jan 2016

Using Photovoltaics To Power Electrochemical Chloride Extraction From Concrete, Sean Bond, Lynette O'Callaghan, Niall Holmes Dr., Brian Norton

Conference papers

Corrosion of embedded steel in reinforced concrete (RC) is a world-wide problem, that reduces structural performance and lifespan. Chloride attack may be a result of seawater, de-icing salts or contaminated admixtures, brought on by ingress of chlorides into the concrete. Electrochemical Chloride Extraction (ECE) is a non-destructive treatment for contaminated RC structures, that due to uncertainty of treatment times and applied current densities, is only 50% effective. It is often diesel powered has an environmental impact and often very costly due to the long treatment times. To improve the efficiency of ECE the influences of concrete resistance, cement type and …


Cultural Change Through Bim: Driving Lean Transformation In Education, Avril Behan, Malachy Mathews, Kevin Furlong, Ciara Ahern, Una Beagon, Peter Brennan, Colin Conway, Lee Corcoran, Pierce Fahy, Alan Hore, Barry Mcauley, Trevor Woods Nov 2015

Cultural Change Through Bim: Driving Lean Transformation In Education, Avril Behan, Malachy Mathews, Kevin Furlong, Ciara Ahern, Una Beagon, Peter Brennan, Colin Conway, Lee Corcoran, Pierce Fahy, Alan Hore, Barry Mcauley, Trevor Woods

Conference papers

This paper presents a case study of how the adoption of BIM-based practices in the AECO industry is being reflected by cultural change in higher education in Ireland. The silo-mentality that has dominated the AECO sector for more than a century has, despite numerous reorganisations, been replicated in the structures of educational institutions, including in Dublin Institute of Technology since the inception of its founding colleges in the late 1800s. Most AECO programmes must include content that is external to the programme’s specific discipline. Through the School structures of the Institute, delivery of such content is known as "service teaching" …


Shark Alert: Early Warning System, Cory Peterson, Marc Rauschnot, Taylor Mcclain Jun 2015

Shark Alert: Early Warning System, Cory Peterson, Marc Rauschnot, Taylor Mcclain

Electrical Engineering

The Shark Alert Early Warning System is a device geared toward avid beach goers such as surfers, divers, and swimmers. The system is composed of an ultrasonic transmitter mounted on a shark’s dorsal fin and a receiver worn by the user around the ankle. The receiver alerts the user to the presence of a shark upon ultrasonic signal detection.

The receiver warns the user through both visual and tactile (vibration) alerts to ensure user notification. This circuit was built and tested in the EE labs and Recreation Center pools to determine transmission range. The receiver detects the transmitted signal up …


Loss Modeling Of A Permanent Magnet Dc Motor Drive Water Pumping System, Nelson Lujara Dec 2014

Loss Modeling Of A Permanent Magnet Dc Motor Drive Water Pumping System, Nelson Lujara

Tanzania Journal of Engineering and Technology (TJET)

The paper presents an analytical approach to the determination of losses in each of the sub-systems of the Photovoltaic (PV) Permanent Magnet DC Motor (PMDC) drive water pumping system with and without maximum power tracking. The losses of the system at varying heads are firstly, determined using parameters from the data sheets and then validated by experimental results. The results are used to establish the head and the flow rate optimal operating point of the system.


Analysis Of Power Efficiency Of A Direct-Driven Locally Fabricated Permanent Magnet Ac Generator For Small-Scale Wind Power Applications In Tanzania, Mussa Iddi Mgwatu Dr. Dec 2013

Analysis Of Power Efficiency Of A Direct-Driven Locally Fabricated Permanent Magnet Ac Generator For Small-Scale Wind Power Applications In Tanzania, Mussa Iddi Mgwatu Dr.

Tanzania Journal of Engineering and Technology (TJET)

The use of direct-driven permanent magnet alternating current (AC) generators offers the opportunity to reduced costs and increased system efficiency. This type of generator could be the best alternative for rural population whom are not connected to the national grid. To improve the design and efficiency of locally fabricated generators, it is imperative to characterize both their mechanical and electrical parameters. This paper presents the analysis of power efficiency of the synchronous permanent AC generator locally fabricated in Tanzania. In this case, load resistance and rotational speed are characterized using designed experiment. The output current and voltage of the generator …


Lunalight - Bringing Light To The Expanding World, Gabriela M. Igel, Daniel J. Patrick, Kimberley M. Smith Jun 2013

Lunalight - Bringing Light To The Expanding World, Gabriela M. Igel, Daniel J. Patrick, Kimberley M. Smith

Materials Engineering

The LunaLight, a solar rechargeable light and cell phone charger, addresses the lack of access to electricity faced by 1.4 billion of the world’s population (International Finance Corporation). The LunaTech team has developed a product that is bright, simple, compact, versatile and competitive with existing products. Through a partnership with the non-profit organization One Million Lights, LunaTech has improved a previous team’s design to address user feedback, concerns of durability, and manufacturability.

The LunaLight design includes a 5 component plastic housing held together by 4 screws, a surface mounted PCB, a lithium-ion (Li-Ion) battery, one high-brightness LED, a solar panel, …


Cal Poly Brocade Challenge 2013, Chandler Morehardt, Alexa Coburn, Juan Silva, Kerry Sun, Greg Wang, Raul Chagoya, Jd Torres Jun 2013

Cal Poly Brocade Challenge 2013, Chandler Morehardt, Alexa Coburn, Juan Silva, Kerry Sun, Greg Wang, Raul Chagoya, Jd Torres

Architectural Engineering

No abstract provided.


Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs), Travis R. Ward Aug 2011

Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs), Travis R. Ward

Master's Theses

This study focuses on both the numerical and experimental investigations of the novel, passively operated, tubular-shaped, Direct Methanol Fuel Cell (DMFC) as an alternative geometry to the traditional planar-shaped fuel cell. The benefit of the tubular geometry compared to the planar geometry is the higher instantaneous volumetric power density provided by the larger active area, which could be beneficial in applications that require a high instantaneous power while occupying a small volume. First, a two-dimensional, two-phase, non-isothermal model was developed to investigate the steady-state performance and design characteristics of a tubular-shaped, passive DMFC. It was found that a higher ambient …