by Deewakar Poudel  , Benjamin Belfore  , Shankar Karki  , Grace Rajan  , Sina Soltanmohammad  , Angus Rockett  and Sylvain Marsillac

Received: 28 October 2020;  Published: 06 January 2021;  doi: 10.21926/jept.2101001

The effect of water ingress on the surface of the buffer layer of a Cu(In, Ga)Se2 (CIGS) solar cell was studied. Such degradation can occur either during the fabrication process, if it involves a chemical bath as is often the case for CdS, or while the modules are in the field and encapsulants degrade. To simulate the impact of this moisture ingress, devices with a structure sodalime glass/Mo/CIGS/CdS were immersed in deionized water. The thin films were then analyzed both pre and post water soaking. Dynamic second [...]

by Wisut Chamsa-ard  , Derek Fawcett  , Chun Che Fung  and Gerrard Poinern

Received: 28 September 2020;  Published: 29 December 2020;  doi: 10.21926/jept.2004018

The demand for high-quality freshwater is increasing due to global population growth, intensifying agricultural practices and expanding industrial development. Additionally, many global regions have low levels of rainfall which makes them arid and incapable of supporting large human populations or agriculture. Currently, large quantities of fossil fuels are used to generate the power needed to drive energy intensive desalination processes that deliver high-quality freshwater to many of these regions. However, the u [...]

by Samuel Cruz-Manzo

Received: 31 July 2020;  Published: 24 November 2020;  doi: 10.21926/jept.2004017

In this study, uncertainties during the assessment of the electrochemical impedance spectrum of the polymer electrolyte fuel cell (PEFC) attributed to inductive artefacts at high frequencies and inductive loops at low frequencies as well as oxygen diffusion time constant are discussed. A validated impedance model represented as an equivalent electrical circuit of a PEFC allowed the simulation of the effect of inductive artefacts, inductive loops and oxygen diffusion time constant on electrochemical impedance spectr [...]

by Katarzyna Grubel  , Ji Su  , Jotheeswari Kothandaraman  , Kriston Brooks  , Gabor A. Somorjai  and Tom Autrey

Received: 01 September 2020;  Published: 23 November 2020;  doi: 10.21926/jept.2004016

In this perspective on hydrogen carriers, we focus on the needs for the development of robust active catalysts for the release of H2 from aqueous formate solutions, which are non-flammable, non-toxic, thermally stable, and readily available at large scales at reasonable cost. Formate salts can be stockpiled in the solid state or dissolved in water for long term storage and transport using existing infrastructure. Furthermore, formate salts are readily regenerated at moderate pressures using the same catalyst as for [...]

by Jacob Ladenburg

Received: 28 April 2020;  Published: 12 August 2020;  doi: 10.21926/jept.2003015

Visual external costs are significant elements in the cost-benefit analysis of wind farm locations. This has been demonstrated well in the literature. However, in the assessment of the visual costs, a large share of the earlier studies used no or only simplistic visualizations of the visual impacts at stake. The cost estimates thus rely on the respondents’ ability to imagine the visual impacts associated with wind turbines of different sizes and at different locations. This has been argued to potentially reduce the [...]

by Mohammad Jafari  and Zahra Malekjamshidi

Received: 13 June 2020;  Published: 05 August 2020;  doi: 10.21926/jept.2003014

In this paper, a topology of a residential hybrid renewable energy system based on a high-frequency multi-winding transformer is introduced and analyzed. The system includes a PV and a wind-turbine as renewable energy sources, a battery as energy storage and their energies are integrated through a high-frequency transformer. In fact, the transformer integrates the energies in a magnetic form and also isolates the system inputs and outputs. The integrated output from renewables and battery is a DC high-voltage and i [...]

by Najmul Hoque  , Wahidul Biswas  , Ilyas Mazhar  and Ian Howard

Received: 29 June 2020;  Published: 31 July 2020;  doi: 10.21926/jept.2003013

Hydrogen is regarded as a potential solution to address future energy demands and environmental protection challenges. This study assesses the triple bottom line (TBL) sustainability performance of hydrogen as an automotive fuel for Western Australia (WA) using a life cycle approach. Hydrogen is considered to be produced through water electrolysis. Two scenarios, current grid electricity and future renewable-based hydrogen, were compared with gasoline as a base case. The results show that locally produced grid elec [...]

by Peter Leary  , Peter Malin  , Graeme Saunders  and Charles Sicking

Received: 03 December 2019;  Published: 29 July 2020;  doi: 10.21926/jept.2003012

A core feature of convective geothermal resource production is wellbore energy flow Q ~ ρC x T x V. E.g., for wellbore fluid of volume heat capacity ρC ~ 4.3MJ/m3.oC, temperature T ~ 230oC, and volumetric flow V ~ 50L/s, wellbore heat energy production is Q~ 50MWth ~ 5MWe. Wellbore fluid flow V =2πr0ϕv0ℓ for open wellbore length ℓ is given in turn by the spatially variable product crustal porosity times crustal fluid velocity v ≡ ϕv0 at the wellbore rad [...]

by Kosmas A. Kavadias  and Stefanos Tzelepis

Received: 03 June 2020;  Published: 24 July 2020;  doi: 10.21926/jept.2003011

The fluctuations in the cost of energy coupled with the gradual decrease in natural resources (i.e., oil, natural gas, coal) and the environmental issues caused by the extensive use of fossil fuels, demand the urgent need for the development of advanced and clean energy systems. The European Union has requested new measures to target climate and energy deterioration by developing renewable energy sources by 2030. The stochastic character of the energy sources and the fluctuation in demand for the energy systems pos [...]

by Ryan J. Clarke  and David A. Miller

Received: 15 April 2020;  Published: 09 June 2020;  doi: 10.21926/jept.2002010

As wind turbine blades grow longer, new design parameters gain additional importance such as blade weight, tip deflection and material cost. These parameters require designers to relook at carbon fiber as a potential design solution. However, the composite materials in wind turbine blades are subjected to significant compressive loading, and the compressive strength of carbon fiber reinforced polymer (CFRP) composites is much lower than its tensile strength. This reduction in compression strength is due to a change [...]

by Camille Jubert Tomasso  , Anne L. Pham  , Tracy M. Mattox  and Jeffrey J. Urban

Received: 20 April 2020;  Published: 19 May 2020;  doi: 10.21926/jept.2002009

Hydrogen (H2) shows great promise as zero-carbon emission fuel, but there are several challenges to overcome in regards to storage and transportation to make it a more universal energy solution. Gaseous hydrogen requires high pressures and large volume tanks while storage of liquid hydrogen requires cryogenic temperatures; neither option is ideal due to cost and the hazards involved. Storage in the solid state presents an attractive alternative, and can meet the U.S. Department of Energy (DOE) constraints to find m [...]

by Akira Nishimura  , Satoshi Ohata  , Kaito Okukura  and Eric Hu

Received: 25 March 2020;  Published: 14 May 2020;  doi: 10.21926/jept.2002008

Biogas is a promising resource for the production of H2 since it liberates energy by recycling waste, along with the reduction of CO2. In this paper, the biogas dry reforming membrane reactor is proposed to produce H2 for use in fuel cells. Pd/Cu alloy membrane is used to enhance the performance of the biogas dry reforming reactor. This study aims at understanding the effect of operating parameters such as feed ratio of sweep gas, pressure in the reactor, and reaction temperature on the performance of the biogas dr [...]

by Xiang Li  , Yuan Xue  , Ryan Dehoff  , Costas Tsouris  and Patricia Taboada-Serrano

Received: 09 April 2020;  Published: 09 May 2020;  doi: 10.21926/jept.2002007

Hierarchically-structured, electro-catalysts consisting of a titanium core with controlled macro-porosity and a thin titania surface-layer with controlled nano-porosity were synthesized via combination of additive manufacturing and in-situ anodization. The electrodes were tested for hydrogen evolution reaction and depicted competitive electro-catalytic activities, with Tafel slopes between 40 and 56 mV dec-1. The electrodes also depicted competitive onset and over potentials when compared with other electrode alter [...]

by Megan Schutt  and Harvey Seim

Received: 10 April 2020;  Published: 30 April 2020;  doi: 10.21926/jept.2002006

SODAR wind profiler measurements from a land-based site within 1000 m of the coastal ocean are compared with predicted wind profiles based on upwind conditions and a stability-based model. The thermally dynamic influence of the Gulf Stream near the site of measurement, Cape Hatteras, has been found to complicate wind speed estimation at height through its impacts on atmospheric stability and the resulting changes to wind shear. The COARE 3.0 algorithm was used to calculate a Monin-Obukhov Similarity Theory (MOST) s [...]

by Max F. Platzer  and Nesrin Sarigul-Klijn

Received: 28 January 2020;  Published: 29 April 2020;  doi: 10.21926/jept.2002005

The current status of a project is described which aims to demonstrate the technical and economic feasibility of converting the vast wind energy available over the globe’s oceans and lakes into storable energy. To this end, autonomous high-performance sailing ships are equipped with hydrokinetic turbines whose output is stored either in electric batteries or is fed into electrolysers to produce hydrogen which then is compressed and stored in tanks. In the present paper, the previous analytical studies which showed [...]

by Manuel Legree  , Jocelyn Sabatier  , Fabrice Mauvy  , Abdel Salam Awad  , Matthieu Faessel  , Frederic Bos  and Jean-Louis Bobet

Received: 04 March 2020;  Published: 28 April 2020;  doi: 10.21926/jept.2002004

This paper focuses on hydrogen production for green mobility applications (other applications are currently under investigation). Firstly, a brief state of the art of hydrogen generation by hydrolysis with magnesium is shown. The hydrolysis performance of Magnesium powder ball–milled along with different additives (graphite and transition metals TM = Ni, Fe, and Al) is taken for comparison. The best performance was observed with Mg–10 wt.% g mixtures (95% of theoretical hydrogen generation yield in about 3 min). An [...]

by Tyler Campbell  and Sergey Stolbov

Received: 16 February 2020;  Published: 20 April 2020;  doi: 10.21926/jept.2002003

In the search for new efficient photo-catalysts for hydrogen production through water splitting, the main attention has been paid to tuning the band gap width and its position with respect to vacuum level. However, actual electro-catalytic activity for the water oxidation reaction on a catalyst surface is no less important than those quantities. In this work we evaluate from first principles the thermodynamics of the reaction on relatively new candidates for water splitting: two-dimensional C2N and that doped with [...]

by Ryosuke Oochi  , Kengo Aoyama  and Akira Ueda

Received: 27 November 2019;  Published: 12 February 2020;  doi: 10.21926/jept.2001002

In order to achieve advancement in zero-emission geothermal power generation for fixing the CO2 in the geothermal fluids to the carbonate minerals after binary power generation and reinjection of the fluid into the reservoir, batch-type experiments and geochemical simulations of CO2-andesitic pyroclastic rock interaction (tuff from Oku-Aizu geothermal area) were performed at 150 °C with and without CO2 gas for 15 days. Despite the low Ca content (0.9% wt.%) in the rock, the Ca2+ concentrations in the solutions [...]

by Nikolai A. Zarkevich

Received: 30 September 2019;  Published: 06 January 2020;  doi: 10.21926/jept.2001001

Most power plants produce electricity by converting a mechanical motion into alternating current (AC). Photovoltaic solar panels convert an electromagnetic flux of light into direct current (DC). In general, electric energy can be harvested from a flux in the environment or from a change of the environment itself. One can produce electricity from mechanical, chemical, thermal, electromagnetic (light), or another physical flux, or from a change of temperature, chemical composition, or a physical field: gravitationa [...]

by Misirkhan A. Talybov  , Lala A. Azizova  and Ilmutdin M. Abdulagatov

Received: 24 September 2019;  Published: 24 December 2019;  doi: 10.21926/jept.1904006

Background: In the present study, vapor-pressures of three geothermal fluids from Baden-Baden geothermal field (Kirchenstollen, Friedrichstollen, and Murquelle, southeastern region of Germany) were measured over the temperature range of 274-413 K. The combined expanded uncertainty of the temperature and vapor-pressure measurements at 95% confidence level with a coverage factor of k = 2 were estimated to be 0.01 K and 1-3 Pa at low and 10-30 Pa at high temperatures, respectively. The measured values of vapor-pressur [...]

by Anna Karmazina  and Brent S. Steel

Received: 18 November 2019;  Published: 24 December 2019;  doi: 10.21926/jept.1904005

The 2013 Pacific Coast Action Plan on Climate and Energy signed by the Governors of Oregon, California, and Washington and the Premier of British Columbia, launched a broadly announced public commitment to reduce greenhouse gas emissions through multiple strategies. Those strategies include the development and increased use of renewable energy sources. The initiative recognized that citizens are both a central component to abating greenhouse gas emissions with regard to their energy use behaviors, and are important [...]

by Iman Rahimi  , Reza Behmanesh  and Abdollah Ahmadi

Received: 21 May 2019;  Published: 15 November 2019;  doi: 10.21926/jept.1904004

The aim of this paper is the scientometric analysis of articles on “scheduling in renewable energy” that have been published between 2000 and 2017. For this purpose, the terms “scheduling in renewable energy” and “unit commitment in renewable energy” have been searched. We have found 1009 articles in the Scopus database which include the terms mentioned above. VOSviewer and CiteSpace, as two well-known the scientometric analysis tools, have been used. Keywords analysis and citation analysis are two analysis methods [...]

by Ugo Chiocchini  and Giovanni Savarese

Received: 14 May 2019;  Published: 05 September 2019;  doi: 10.21926/jept.1903003

Background: The Regione Lazio-Direzione Regionale dello Sviluppo Economico e delle Attività Produttive (RL–DRSEAP), carrying out its public functions to govern the use of mineral resources (including thermal water), planned the exploitation of the Viterbo hydrothermal system on the basis of a conceptual hydrogeological model (CHM). The CHMs of the Viterbo area and that of the neighboring Tuscany region, characterized by the same geological and hydrogeological setting, are discussed, suggesting the unreliability of [...]

by Babkir Ali

Received: 30 May 2019;  Published: 07 August 2019;  doi: 10.21926/jept.1903002

The main objective of this paper is to study the sustainability of power generation from an abandoned oil and gas well in the province of Alberta, Canada. Economic and environmental indicators were used for the sustainability assessment. A conceptual design for a pilot plant was developed, and the main parameters were determined. An abandoned oil and gas well represents the thermal power source through circulating water into an organic Rankine cycle (ORC) unit to generate electricity. The thermal power is extracted [...]

by Babkir Ali

Received: 23 May 2019;  Published: 23 July 2019;  doi: 10.21926/jept.1903001

This paper is intended to evaluate the economic viability of producing solar photovoltaic modules in Sudan. The simple payback period and the net present value were used as economic indicators to study comparatively different annual production capacities. Initial and operating costs were developed and analyzed for the product lifecycle. The number of working shifts in the base case is doubled to achieve a production rate of 20 MW/year and double shift with double quantity of machines is executed to reach a producti [...]