Overview of current development in electrical energy storage technologies and the application potential in power system operation

Climate change and fossil fuel depletion are the main reasons leading to hydrogen technology. There are many processes for hydrogen production from both conventional and alternative energy resources such as natural gas, coal, nuclear, biomass, solar and wind. In this work, a comparative overview of the major hydrogen production methods is carried out. The process descriptions along with the technical and economic aspects of 14 different production methods are discussed. An overall comparison is carried out, and the results regarding both the conventional and renewable methods are presented. The thermochemical pyrolysis and gasification are economically viable approaches providing the highest potential to become competitive on a large scale in the near future while conventional methods retain their dominant role in H2 production with costs in the range of 1.34–2.27 $/kg. Biological methods appear to be a promising pathway but further research studies are needed to improve their production rates, while the low conversion efficiencies in combination with the high investment costs are the key restrictions for water-splitting technologies to compete with conventional methods. However, further development of these technologies along with significant innovations concerning H2 storage, transportation and utilization, implies the decrease of the national dependence on fossil fuel imports and green hydrogen will dominate over the traditional energy resources.

A comparative overview of hydrogen production processes

There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries.

Functional Materials for Rechargeable Batteries

Large-scale deployment of intermittent renewable energy (namely wind energy and solar PV) may entail new challenges in power systems and more volatility in power prices in liberalized electricity markets. Energy storage can diminish this imbalance, relieving the grid congestion, and promoting distributed generation. The economic implications of grid-scale electrical energy storage technologies are however obscure for the experts, power grid operators, regulators, and power producers. A meticulous techno-economic or cost-benefit analysis of electricity storage systems requires consistent, updated cost data and a holistic cost analysis framework. To this end, this study critically examines the existing literature in the analysis of life cycle costs of utility-scale electricity storage systems, providing an updated database for the cost elements (capital costs, operational and maintenance costs, and replacement costs). Moreover, life cycle costs and levelized cost of electricity delivered by electrical energy storage is analyzed, employing Monte Carlo method to consider uncertainties. The examined energy storage technologies include pumped hydropower storage, compressed air energy storage (CAES), flywheel, electrochemical batteries (e.g. lead–acid, NaS, Li-ion, and Ni–Cd), flow batteries (e.g. vanadium-redox), superconducting magnetic energy storage, supercapacitors, and hydrogen energy storage (power to gas technologies). The results illustrate the economy of different storage systems for three main applications: bulk energy storage, T&D support services, and frequency regulation.

Electrical energy storage systems: A comparative life cycle cost analysis

Due to the stochastic nature of wind, electric power generated by wind turbines is highly erratic and may affect both the power quality and the planning of power systems. Energy Storage Systems (ESSs) may play an important role in wind power applications by controlling wind power plant output and providing ancillary services to the power system and therefore, enabling an increased penetration of wind power in the system. This article deals with the review of several energy storage technologies for wind power applications. The main objectives of the article are the introduction of the operating principles, as well as the presentation of the main characteristics of energy storage technologies suitable for stationary applications, and the definition and discussion of potential ESS applications in wind power, according to an extensive literature review.

A review of energy storage technologies for wind power applications

Energy-storage technologies and electricity generation

The adsorption, electrosorption, and electrodesorption of aqueous, inorganic arsenic on the granular activated carbon (GAC), DARCO 12 × 20 (Darco 1220) GAC, were investigated in solutions containing arsenic as the only contaminant, as well as with chromium, nickel, and iron Darco 1220 was selected for these investigations primarily because it is relatively ineffective as a normal (unassisted) arsenic adsorbent in the chosen electrolytes at the low loadings used It is shown that the application of anodic potentials in the 10−15 V range, however, result in enhanced uptake, most likely because of charging of the electrochemical double layer at the electrode surface Regeneration (100%) of electrosorbed arsenic was achieved via electrodesorption at a cathodic potential of 150 V The presence of metal ad ions was observed to have a significant and complex effect on arsenic adsorption, electrosorption, and electrodesorption In particular, the Cr/As ratio was shown to have complex effects, decreasing adsor

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Electrosorption/Electrodesorption of Arsenic on a Granular Activated Carbon in the Presence of Other Heavy Metals.

The adsorption, electrosorption, and electrodesorption of aqueous, inorganic arsenic on the granular activated carbon (GAC), DARCO 12 × 20 (Darco 1220) GAC, were investigated in solutions containing arsenic as the only contaminant, as well as with chromium, nickel, and iron. Darco 1220 was selected for these investigations primarily because it is relatively ineffective as a normal (unassisted) arsenic adsorbent in the chosen electrolytes at the low loadings used. It is shown that the application of anodic potentials in the 1.0−1.5 V range, however, result in enhanced uptake, most likely because of charging of the electrochemical double layer at the electrode surface. Regeneration (100%) of electrosorbed arsenic was achieved via electrodesorption at a cathodic potential of 1.50 V. The presence of metal ad ions was observed to have a significant and complex effect on arsenic adsorption, electrosorption, and electrodesorption. In particular, the Cr/As ratio was shown to have complex effects, decreasing adsor...

Electrosorption/Electrodesorption of Arsenic on a Granular Activated Carbon in the Presence of Other Heavy Metals

The performance and characterization of a batch, direct carbon fuel cell (DCFC), employing molten hydroxide electrolytes, is presented. Particular attention was focused on reducing the operating temperature of the system to minimize corrosion of both fuel cell materials and fuel carbon. Constant power was achieved over a current density range of 37 to 92 mA/cm2 (200 to 500 mA) with NaOH electrolyte at 550 °C, and up to 170 mA/cm2 with a NaOH/KOH (54/46 mol %) eutectic. The voltage decreased with temperature, becoming unstable at ≤400 °C. Electrochemical impedance spectroscopy (EIS) measurements showed that charge-transfer resistance, Rp, is more temperature-dependent than the ohmic resistance, Ro, with Rp decreasing by 55% for the anode and 82% for the cathode with an increase in temperature from 370 °C to 500 °C. Stable operation was achieved at temperatures as low as 400 °C with the hydroxide eutectic electrolyte. This was attributed to the higher concentration of superoxide ions in the eutectic, as ide...

Euan James Bain

Papers

Energy-storage technologies and electricity generation

Electrosorption/Electrodesorption of Arsenic on a Granular Activated Carbon in the Presence of Other Heavy Metals.

Electrosorption/Electrodesorption of Arsenic on a Granular Activated Carbon in the Presence of Other Heavy Metals

Development of a Low Temperature, Molten Hydroxide Direct Carbon Fuel Cell

Arsenic removal via ZVI in a hybrid spouted vessel/fixed bed filter system