Open Access. Powered by Scholars. Published by Universities.®

Energy Systems Commons

Open Access. Powered by Scholars. Published by Universities.®

4,713 Full-Text Articles 1,864 Authors 795,053 Downloads 93 Institutions

All Articles in Energy Systems

Faceted Search

4,713 full-text articles. Page 1 of 83.

Numerical Modeling Of Advanced Propulsion Systems, Peetak P. Mitra 2021 University of Massachusetts Amherst

Numerical Modeling Of Advanced Propulsion Systems, Peetak P. Mitra

Doctoral Dissertations

Numerical modeling of advanced propulsion systems such as the Internal Combustion Engine (ICE) is of great interest to the community due to the magnitude of compute/algorithmic challenges. Fuel spray atomization, which determines the rate of fuel-air mixing, is a critical limiting process for the phenomena of combustion within ICEs. Fuel spray atomization has proven to be a formidable challenge for the state-of-the-art numerical models due to its highly transient, multi-scale, and multi-phase nature. Current models for primary atomization employ a high degree of empiricism in the form of model constants. This level of empiricism often reduces the art of ...


Lifetime And Performance Alteration Of Photovoltaic Panels, The Case Of Aerzen, Germany, Furkan Dinçer 2021 Kahramanmaras Sutcu Imam University

Lifetime And Performance Alteration Of Photovoltaic Panels, The Case Of Aerzen, Germany, Furkan Dinçer

Dicle University Journal of Engineering

Solar energy is unlimited, flawlessly, sustainable and among of the most preferred renewable energy source. The rapid development and the increasing demand in solar energy technologies provided an increasing the production and played an important role for reducing costs. Thousands of manufacturers around the world produce solar panels however solar panels are also exposed to aging during their lifetime. This aging of the solar panel is generally expressed by the manufacturers as 10% generation performance loss in 10 years and 20% in 25 years. However, solar panel technology is not a very old technology and these statements on aging are ...


Experimental And Computational Study Of Determining Mass Transport Parameters In Vanadium Redox Flow Batteries, Tugrul Y. Ertugrul 2021 University of Tennessee, Knoxville

Experimental And Computational Study Of Determining Mass Transport Parameters In Vanadium Redox Flow Batteries, Tugrul Y. Ertugrul

Doctoral Dissertations

Vanadium redox flow batteries are a promising large-scale energy storage technology, but a number of challenges must be overcome for commercial implementation. At the cell level, mass transport contributes significantly to performance losses, limiting VRFB performance. Therefore, understanding mass transport mechanisms in the electrode is a critical step to mitigating such losses and optimizing VRFBs.

In this study, mass transport mechanisms (e.g. convection, diffusion) are investigated in a VRFB test bed using a strip cell architecture, having 1 cm2 active area. It is found that diffusion-dominated cells have large current gradients; convection-dominated cells have relatively uniform current distribution ...


An Improved Earned Value Management Method Integrating Quality And Safety, Brian Briggs 2021 Louisiana State University and Agricultural and Mechanical College

An Improved Earned Value Management Method Integrating Quality And Safety, Brian Briggs

LSU Doctoral Dissertations

The construction industry invests significant time and money to improve quality and safety while reducing cost and schedule impacts. The industry has a sincere desire to improve construction project management methods to improve efficiency. Historically, quality and safety underperformances result from undermanaged quality control and safety activities. The cost and schedule impacts associated with poor quality work have always had an impact on construction operations. The unprecedented challenges and uncertainties of COVID-19 highlighted the need to improve the Earned Value Management (EVM) method within construction to reflect these quality and safety activities. The central goal of this dissertation is to ...


Global Gas-Phase Oxidation Rates Of Select Products From The Fast Pyrolysis Of Lignocellulose, Chad Peterson, Robert C. Brown 2021 Iowa State University

Global Gas-Phase Oxidation Rates Of Select Products From The Fast Pyrolysis Of Lignocellulose, Chad Peterson, Robert C. Brown

Mechanical Engineering Publications

The oxidation kinetics for products of fast pyrolysis at low temperatures (<600 °C) are not well-known. These will be important in an effort to model autothermal pyrolysis, which has been recently developed to intensify the process but which occurs at much lower temperatures than combustion. This study determines global oxidation rates at 400–600 °C for three important products of fast pyrolysis: levoglucosan, xylose, and acetic acid. Experiments were performed in a fluidized bed pyrolyzer with the reactor modeled as a series of continuously stirred reactors and plug flow reactors to determine reaction rates. Oxidation rates at 500 °C for the three model compounds varied by a factor of 10.


Tribological Studies Of Thick Polytetrafluoroethylene Coatings Enhanced By Polydopamine And Nanoparticles, Sujan Kumar Ghosh 2021 University of Arkansas, Fayetteville

Tribological Studies Of Thick Polytetrafluoroethylene Coatings Enhanced By Polydopamine And Nanoparticles, Sujan Kumar Ghosh

Graduate Theses and Dissertations

Polytetrafluoroethylene (PTFE) is a popular low friction solid lubricant with high chemical and thermal stability. Thick PTFE coatings have the potential for many tribological applications, such as replacing Tin-based Babbitt materials in journal bearings. However, the weak bonding strength to the substrate and the high wear rate of PTFE coatings are current limiting factors. The lack of understanding of their tribological properties and wear mechanisms in oil-lubricated conditions and how coating thickness affects the tribological performance further hindered the use of PTFE coatings. In this dissertation, polydopamine (PDA), a bio-inspired adhesive, is used as an underlayer for or as a ...


Development Of Novel Battery Materials For Lithium-Ion Batteries And Beyond, Jiyu Cai 2021 University of Arkansas, Fayetteville

Development Of Novel Battery Materials For Lithium-Ion Batteries And Beyond, Jiyu Cai

Graduate Theses and Dissertations

As fossil fuels are depleting and causing environmental issues, it becomes imperative to widely implement renewable energies (e.g., solar and wind power). In this context, electrical energy storage (EES) systems are essential to accommodate the intermittent supply and uneven distribution of renewable energies. To this end, high-energy-density EES devices are highly demanded, such as rechargeable batteries. This dissertation presents my efforts in developing novel battery materials for lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), and solidstate lithium batteries (SSLBs). These efforts include electrochemical evaluations of battery materials, surface modifications of electrodes via atomic layer deposition (ALD), and advanced characterizations of ...


Connected Water Heater Load Shifting And Energy Efficiency Evaluation For The Southeast: Winter Laboratory Assessment, Final Report, Florida Solar Energy Center, Karen Fenaughty 2021 Florida Solar Energy Center

Connected Water Heater Load Shifting And Energy Efficiency Evaluation For The Southeast: Winter Laboratory Assessment, Final Report, Florida Solar Energy Center, Karen Fenaughty

FSEC Energy Research Center®

The University of Central Florida's FSEC Energy Research Center (FSEC) and Pacific Northwest National Laboratory (PNNL) are conducting laboratory electrical load shifting experiments using the CTA-2045-A standard to demonstrate the viability of grid-connected heat pump water heaters (HPWH), compared to electric resistance water heaters (ERWH), in providing load shifting in the Southeastern United States (U.S.). The investigation applied different CTA-2045 shed and critical peak (CP) control command designs under two different water draw profiles. The highly-controlled laboratory experiments were conducted on four HPWHs and one ERWH from December 2020 through February 2021.

The research aimed to evaluate the ...


Comparison Of The Residential Provisions Of The 7th Edition (2020) Florida Building Code, Energy Conservation With The 2021 Iecc, Florida Solar Energy Center, Jeffrey Sonne 2021 Florida Solar Energy Center

Comparison Of The Residential Provisions Of The 7th Edition (2020) Florida Building Code, Energy Conservation With The 2021 Iecc, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

This report provides a comparison between the 7th Edition (2020) Florida Building Code, Energy Conservation (FBC-EC) and 2021 International Energy Conservation Code (IECC), based on approved 2018 to 2021 IECC changes included in the International Code Council's Complete Revision History to the 2021 I-Codes document. The first part of this study involved developing code change listings based on the Revision History document that identify changes that have potential energy and cost impacts. This second part of the study provides a stringency evaluation and cost-benefit analysis for those changes that impact energy use, to provide guidance for the upcoming 2020 ...


Low Moisture Anhydrous Ammonia Pretreatment Of Four Lignocellulosic Materials—Distillers Dried Grains With Solubles, Corn Gluten Feed, Corn Fiber, And Oil Palm Frond, Nazira Mahmud, Kurt A. Rosentrater 2021 Iowa State University and Universiti Malaysia Pahang

Low Moisture Anhydrous Ammonia Pretreatment Of Four Lignocellulosic Materials—Distillers Dried Grains With Solubles, Corn Gluten Feed, Corn Fiber, And Oil Palm Frond, Nazira Mahmud, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Publications

Lignin and hemicellulose structures in cellulosic materials serve as a barrier for enzyme reactions. A pretreatment step is often needed to break these components to allow the biomass to be utilized as a source of value-added products. Various available pretreatment methods possess common drawbacks of the high amount of liquid and chemical requirements, harsh process conditions, and the high amount of waste produced, which driving up the production costs of bioproducts. Low moisture anhydrous ammonia (LMAA) pretreatment capable of eliminating those drawbacks. In this study, Distillers Dried Grains with Solubles (DDGS), corn gluten feed (CGF), corn fiber (CF), and oil ...


Machine Learning Reduced Order Model For Cost And Emission Assessment Of A Pyrolysis System, Olumide Olafasakin, Yahan Chang, Alberto Passalacqua, Shankar Subramaniam, Robert C. Brown, Mark Mba Wright 2021 Iowa State University

Machine Learning Reduced Order Model For Cost And Emission Assessment Of A Pyrolysis System, Olumide Olafasakin, Yahan Chang, Alberto Passalacqua, Shankar Subramaniam, Robert C. Brown, Mark Mba Wright

Mechanical Engineering Publications

Biomass pyrolysis is a promising approach for producing economic and environmentally friendly fuels and bioproducts. Biomass pyrolysis experiments show that feedstock properties have a significant impact on product yields and composition. Scientists are developing detailed chemical reaction mechanisms to capture the relationships between biomass composition and pyrolysis yields. These mechanisms can be computationally intensive. In this study, we investigate the use of a machine learning reduced order model (ROM) for assessing the costs and emissions of a pyrolysis biorefinery. We developed a Kriging-based ROM to predict pyrolysis yields of 314 feedstock samples based on the results of a detailed chemical ...


Consumer-Ready Insulated Solar Electric Cooker, Simon Ford, Sachin Gokhale, Brendan Lynn, Richard Nguyen 2021 California Polytechnic State University, San Luis Obispo

Consumer-Ready Insulated Solar Electric Cooker, Simon Ford, Sachin Gokhale, Brendan Lynn, Richard Nguyen

Mechanical Engineering

An insulated solar electric cooker, or ISEC, converts solar energy into electricity to cook food, boil water, provide heat or even help charge batteries. In this project, the focus is an ISEC with a phase change material (PCM) that helps store heat when the solar energy input is minimal, such as after the sun has set. Although a successful ISEC already exists that utilizes PCM, this product can be improved in many ways. The specific revisions investigated in this report are the improvement of the thermal efficiency with the implementation of a vacuum-sealed outer pot, the reduction of the overall ...


Sustainable Tiny Home, Abigail Jessica Jones, Vince John Bugni, Sean Robert Paddy, Cameron Michael Gross 2021 California Polytechnic State University, San Luis Obispo

Sustainable Tiny Home, Abigail Jessica Jones, Vince John Bugni, Sean Robert Paddy, Cameron Michael Gross

Mechanical Engineering

As housing prices and environmental concerns continue to increase, many people are looking for cheaper and more sustainable ways to live. A solution to both problems is building homes with smaller footprints which incorporate renewable energy and water-reclamation systems. In addition, adding a roof pond system to the dwelling also reduces the need for heating and cooling. The roof pond system uses a water bladder on the roof which acts as a heat-sink and moveable insulation panels. This document contains the process for our final design along with results from testing the verification prototype.


Sustainable Energy Storage, Jacob S. Grillo, Alyse C. Coonce, Jack R. Linchey, Nick P. Schnorr 2021 California Polytechnic State University, San Luis Obispo

Sustainable Energy Storage, Jacob S. Grillo, Alyse C. Coonce, Jack R. Linchey, Nick P. Schnorr

Mechanical Engineering

This Final Design Review document covers the work we, students at California Polytechnic State University – San Luis Obispo, have performed in collaboration with Mr. Harish Bhutani and Dr. Mohammad Noori. The project’s intent is to create an energy storage system for off-grid and developing region applications using alternative technologies to lithium-ion battery storage. We plan to manufacture and assemble a scale model of the energy storage system to prove effectiveness and practicality. This system will store enough energy to power basic appliances and essential devices for a house or community. The chosen design direction will be a flywheel, as ...


Cal Poly Wind Power: Wind Turbine Prototype, Sophie A. Spencer, Maggie Nevrly, Michael Reyna, Loi Q. Nguyen 2021 California Polytechnic State University, San Luis Obispo

Cal Poly Wind Power: Wind Turbine Prototype, Sophie A. Spencer, Maggie Nevrly, Michael Reyna, Loi Q. Nguyen

Mechanical Engineering

The Cal Poly Wind Power (CPWP) club is competing in the Collegiate Wind Competition (CWC) hosted by the National Renewable Energy Laboratory (NREL). The CWC is hosted annually by NREL to increase the number of skilled workers prepared to work in the wind energy industry. Our senior project team is one of several design teams contributing to the CPWP prototype turbine design including the pitching mechanism, blade design, generator, and shaft. The scope of this project is to design the yaw mechanism, tower, and nacelle. The goal is to create components that function well with other planned components and are ...


Power Output Modeling And Optimization For A Single Axis Tracking Solar Farm On Skewed Topography Causing Extensive Shading, Logan J. Smith 2021 California Polytechnic State University, San Luis Obispo

Power Output Modeling And Optimization For A Single Axis Tracking Solar Farm On Skewed Topography Causing Extensive Shading, Logan J. Smith

Master's Theses

Many utility-scale solar farms use horizontal single axis tracking to follow the sun throughout the day and produce more energy. Solar farms on skewed topography produce complex shading patterns that require precise modeling techniques to determine the energy output. To accomplish this, MATLAB was used in conjunction with NREL weather predictions to predict shading shapes and energy outputs. The MATLAB models effectively predicted the sun’s position in the sky, panel tilt angle throughout the day, irradiance, cell temperature, and shading size. The Cal Poly Gold Tree Solar Farm was used to validate these models for various lengths of time ...


Implementing A Data Acquisition System For The Training Of Cloud Coverage Neural Networks, Weston C. Montgomery 2021 California Polytechnic State University, San Luis Obispo

Implementing A Data Acquisition System For The Training Of Cloud Coverage Neural Networks, Weston C. Montgomery

Master's Theses

Cal Poly is home to a solar farm designed to nominally generate 4.5 MW of electricity. The Gold Tree Solar Farm (GTSF) is currently the largest photovoltaic array in the California State University (CSU) system, and it was claimed to be able to produce approximately 11 GWh per year. These types of projections come from power generation models which have been developed to predict power production of these large solar fields. However, when it comes to near-term forecasting of power generation with variable sources such as wind and solar, there is definitely room for improvement.

The two primary factors ...


Mitigation Of Airborne Contaminant Spread Through Simple Interventions In An Occupied Single-Family Home, Florida Solar Energy Center, Nazim Muradov 2021 Florida Solar Energy Center

Mitigation Of Airborne Contaminant Spread Through Simple Interventions In An Occupied Single-Family Home, Florida Solar Energy Center, Nazim Muradov

FSEC Energy Research Center®

Historically, reducing aerosol-based transmission of respired viruses in indoor environments has been of importance for controlling influenza viruses and common-cold rhinoviruses. The present public health emergency associated with SARS-CoV-2 makes this topic critically important. Yet to be tested is the potential effectiveness of simple interventions that create an isolation zone (IZ) for a suspected/confirmed sick or sensitive person requiring quarantine. The intent in existing homes is to find a practical means to mitigate exposure to airborne contaminants. In creating an IZ in an occupied single-family home in the study, four simple strategies were tested. The test configurations were: (1 ...


Techno-Economic Analysis Of Integrating Soybean Biorefinery Products Into Corn-Based Ethanol Fermentation Operations, Kurt A. Rosentrater, Weitao Zhang 2021 Iowa State University

Techno-Economic Analysis Of Integrating Soybean Biorefinery Products Into Corn-Based Ethanol Fermentation Operations, Kurt A. Rosentrater, Weitao Zhang

Agricultural and Biosystems Engineering Publications

With the development of agricultural biorefineries and bioprocessing operations, understanding the economic efficiencies and environmental impacts for these have gradually become popular for the deployment of these industrial processes. The corn-based ethanol and soybean oil refining industries have been examined extensively over the years, especially details of processing technologies, including materials, reaction controls, equipment, and industrial applications. The study focused on examining the production efficiency changes and economic impacts of integrating products from the enzyme-assisted aqueous extraction processing (EAEP) of soybeans into corn-based ethanol fermentation processing. Using SuperPro Designer to simulate production of corn-based ethanol at either 40 million gallons ...


Desalination For Sustainable Water Production With An Emphasis On Low Pressure Distillation, Jessica Vivian Savage 2021 Embry-Riddle Aeronautical University

Desalination For Sustainable Water Production With An Emphasis On Low Pressure Distillation, Jessica Vivian Savage

PhD Dissertations and Master's Theses

Freshwater resources depletion is a growing concern. This freshwater scarcity motivates research into seawater desalination as a means for alleviating the stresses on water demands. The primary methods of desalination include filtration and distillation. This paper explores the potential energy savings of vacuum distillation for seawater desalination to reduce the amount of energy needed to achieve phase change.

Depending on the vacuum boiler design, the vaporization mechanism may be boiling, evaporation, or cavitation. There is very little literature on cavitation that involves mass transfer, so cavitation is not developed here. This thesis focuses on standard models for boiling and evaporation ...


Digital Commons powered by bepress