June 12, 2020
Japan is facing a severe challenge regarding its heavy dependence on fossil fuels: currently they account for 89% of total energy consumption. After the Great East Earthquake, energy security and vulnerability have become critical issues facing the Japanese energy system. The integration of renewable energy sources to meet specific regional energy demand is a promising scenario to overcome these challenges. To this aim, this paper proposes a novel hydrogen-based hybrid renewable energy system (HRES), in which hydrogen fuel can be produced using solar electrolysis and supercritical water gasification (SCWG) of biomass feedstock. The hydrogen would function as an energy storage medium by storing renewable energy until a fuel cell converts it to electricity.
Review of Potential Liquid-Organic Hydrogen Carrier (LOHC) Systems
November 19, 2020
The depletion of fossil fuels and rising global warming challenges encourage to find safe and viable energy storage and delivery technologies. Hydrogen is a clean, efficient energy carrier in various mobile fuel-cell applications and owned no adverse effects on the environment and human health. However, hydrogen storage is considered a bottleneck problem for the progress of the hydrogen economy. Liquid-organic hydrogen carriers (LOHCs) are organic substances in liquid or semi-solid states that store hydrogen by catalytic hydrogenation and dehydrogenation processes over multiple cycles and may support a future hydrogen economy. Remarkably, hydrogen storage in LOHC systems has attracted dramatically more attention than conventional storage systems, such as high-pressure compression, liquefaction, and absorption/adsorption techniques. Potential LOHC media must provide fully reversible hydrogen storage via catalytic processes, thermal stability, low melting points, favorable hydrogenation thermodynamics and kinetics, large-scale availability, and compatibility with current fuel energy infrastructure to practically employ these molecules in various applications. In this review, the authors present various considerable aspects for the development of ideal LOHC systems. They highlight the recent progress of LOHC candidates and their catalytic approach, as well as briefly discuss the theoretical insights for understanding the reaction mechanism.
Operation of Solar-Storage-Hydrogen-Charging System by Value Stream Analysis
April 24, 2020
The topology of the clean energy system is a flexible structure with PV, wind power, hydrogen storage, and battery storage. Thus, the construction and operation of the clean energy system should pay more attention to the temporal and spatial variations. This paper discussed a solar-storage-hydrogen-charging demonstration to accommodate the diverse temporal and spatial features of the clean energy system. The present study developed a Modelica library to support the cooperative control of this clean energy system based on value stream analysis. The result shows that the sold electricity profit of the electric storage system can reach 2.3 times than the electricity purchase cost. Though the hydrogen charging demand in the demonstration is small compared with the electric load demand, the hydrogen charging profit can be 1.7 times of the energy cost.
Hydrogen Production from Offshore Wind Parks
June 16, 2021
Hydrogen has the potential to be combined with offshore wind energy to aid in overcoming disadvantages such as the high installation cost of electrical transmission systems and transmission losses. This paper aims to outline and discuss the main features of the integration of hydrogen solutions in offshore wind power and to offer a literature review of the current state of hydrogen production from offshore wind. The paper provides a summary of the technologies involved in hydrogen production along with an analysis of two possible hydrogen producing systems from offshore wind energy.
Assessment of Energy Storage from Photovoltaic Installations Using Hydrogen or Batteries
August 4, 2020
This paper presents a series of economic efficiency studies comparing three different investment variants: without energy storage, with energy stored in batteries and hydrogen installation with a PEM fuel cell stack for a location in Poland.
Storing Energy as Hydrogen
November 19, 2020
Extensive research on photovoltaics (PV) cooperating with energy storage systems are conducted all over the world. For example, in reference [27] the authors show a PV installation connected with a hydrogen production system. Paper demonstrates that with a proper design of the system proposed by the authors it can operate correctly charging the batteries, supplying the electrolyzer, and occasionally producing excess electricity. The paper [28] presents a self-sufficient solution for residential buildings with photovoltaic and battery storage systems. Model presented by the authors included hybrid PV and hydrogen fuel cell installation with a battery energy storage unit for system optimization. In reference [29] a study of optimum design, size, and economic analysis of photovoltaic installations with a battery system and a standalone photovoltaic with battery and hydrogen production are shown. In another reference [30] authors proposed the photovoltaic-hydrogen-fuel cell installation as a solution for reactive power control and optimization solution which can help improve the quality of supplied power. Another PV-H2 installation is presented by the authors in [31]. The research shows two solutions—with and without batteries’ subsystem, as well as two different locations to find the best balance between the efficiency and sizes of the installations. Photovoltaic systems are also frequently connected with wind installations in hybrid units for hydrogen production [32,33]. Review of recent trends in optimization techniques for PV-wind hybrid energy systems are presented in [34]. Solutions for systems containing photovoltaic installations with Proton Exchange Membrane (PEM) electrolyzers for hydrogen production are presented in [35,36,37].
Storing Hydrogen
October 19, 2020
In some areas, the problem of wind and solar power curtailment is prominent. Hydrogen energy has the advantage of high storage density and a long storage time. Multi-energy hybrid systems including renewable energies, batteries and hydrogen are designed to solve this problem.
Dissociation Of Water Into Hydrogen And Oxygen Through A Combination Of Electrolysis And Photocatalyst
July 28, 2020
In this paper, through a review of the literature, a method of separating hydrogen and oxygen from water through a photocatalysis process that utilizes the energy of photons from visible light is combined with the electrolysis process to increase hydrogen production with a fairly small current.
Enhancing Photovoltaic Performance of Porous Silicon Solar Cells
April 21, 2021
This work examines nanocrystalline porous silicon (PSi) prepared by electrochemical etching of p type silicon wafers.
Improving Sustainable Hydrogen Production From Green Waste
September 16, 2021
Bio-hydrogen production via dark fermentation of low-value waste is a potent and simple mean of recovering energy, maximizing the harvesting of reducing equivalents to produce the cleanest fuel amongst renewables. Here, an alternative application of green wastes, low-value compost and intermediate products (partially composted but unsuitable for completing the process) is studied, pointing at the autochthonous microbial consortium as an already selected source of implementation for biomass degradation and hydrogen production.