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 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 that [...]