Low Electrical Consumption Research Articles

Design and analysis of biomass-to-ammonia-to-power as an energy storage method in a renewable multi-generation system

To solve the problem of unevenly distributed renewables and increase their penetration, large-scale energy storage is necessary. Green hydrogen is suitable for bulk energy storage; however, it still faces storage problems. Therefore, green ammonia has been proposed as a substitute for hydrogen. The combination of renewables and green ammonia production can achieve cross-sector decarbonization. However, the potential of green ammonia as an energy carrier requires further investigation. This paper reports the design and analysis of a renewable multi-generation system for electricity, heat, and green ammonia, where biomass-to-ammonia-to-power is used as an energy storage method. This concept combines renewable power generation, biomass chemical-looping ammonia production, and direct ammonia fuel cells. The results indicated that the maximum energy and exergy efficiencies were 60.1% and 56.3%, respectively. The system provides 29,582 t·y-1 ammonia and 3,525,305 t·y-1 hot water and captures 171,550 t·y-1 of carbon dioxide. The optimal proportion of key components and relevant design criteria were also determined through sensitivity analysis as well. Compared to systems involving power-to-ammonia-to-power, the higher efficiency, lower electricity consumption for ammonia production, and carbon dioxide capture make biomass-to-ammonia-to-power a promising energy storage method for multigeneration systems.

Interface-confined multi-layered reaction centers between Ce-MOFs and Fe3O4@C for heterogeneous electro-Fenton at wide pH 3–9: Mediation of Ce3+/Ce4+ and oxygen vacancy

• H 2 O 2 generation and multiple reactive species was achieved on Ce-MOFs/Fe 3 O 4 @C as cathode. • The multi-layered reaction centers of O V , Ce 3+ /Ce 4+ and Fe 2+ /Fe 3+ promoted pollutants removal. • Interface confinement was benefit to O 2 adsorption, electron transfer and metal stabilization. • It exhibited low EEC in electro-Fenton and extended wide pH suitability to alkaline. • Ce-MOFs/Fe 3 O 4 @C exhibited efficient degradation for various pollutants and real wastewater. A bifunctional catalyst with Ce-based metal–organic frameworks deposited on carbon encapsulated Fe 3 O 4 particles (Ce-MOFs/Fe 3 O 4 @C) was prepared for heterogeneous electro-Fenton (EF), which exhibited high H 2 O 2 generation efficiency (over 90% selectivity and 80.7% current efficiency), high sulfamethazine (SMT) removal with very low electric energy consumption (7.65 kWh kg −1 SMT), and wider pH suitability to alkaline environment (pH 9). The highest content of oxygen vacancies (O V ), Ce 3+ and Fe 2+ was simultaneously exhibited when the Fe/Ce ratio in precursor was 2:1. Interface-confined between Ce-MOFs and Fe 3 O 4 @C and presence of O V promoted the O 2 adsorption for oxygen reduction reaction and O 2 ∙- generation, and electron transfer between Fe and Ce. Meanwhile, the presence of Fe 2+ /Fe 3+ and Ce 3+ /Ce 4+ simultaneously facilitated the sequential catalysis induced by H 2 O 2 to generate ∙ OH, and Ce 4+ could promote O 2 ∙- to generate 1 O 2 . This work provides new insight into the design and synthesis of Fe-based catalysts in EF with interface confinement and multi-layered reaction centers to improve the generation and the decomposition of H 2 O 2 at the same time at a low cathode potential.

Ammonia-rich solution production from coal gasification gray water using Chemical-free Flow-Electrode capacitive deionization coupled with a monovalent cation exchange membrane

The conventional technologies for ammonia recovery from wastewaters usually requires high chemicals and energy input. And if the wastewater contains hardness, there is a risk of scaling with increasing in cost. Flow electrode capacitive deionization (FCDI) coupled with monovalent cation exchange membrane (MCEM) was employed to solve abovementioned problem. Our method was an effective strategy for the selective production of an ammonia-rich solution from coal gasification gray water by simply adjusting the charging and discharging processes. During the charging process, both NH4+ and Na+ were transported to the cathode due to electrosorption of the electrical double layers (EDLs) on charged carbon particles and electrodialysis of potential gradient, while Ca2+ was retained by the MCEM. The Faradaic reactions induced the generation of OH- and led to the conversion of charged NH4+ into uncharged NH3. When the electrode polarity was reversed, charged species such as Na+ would be mostly pushed back into the spacer chamber, yet NH3 was more likely to be trapped in the cathode due to sluggish pH variations, thereby producing an ammonia-rich solution. Under optimal operating conditions (i.e., a carbon content of 5 wt%, charge and discharge voltages of 4.5 and 0.2 V, respectively, charge 80 min and discharging 15 min, and six continuous cycles), a stable recovery efficiency (∼205 mg/L per cycle) and product purity of 70.4% were attained at a relatively low electrical energy consumption (11.1 kWh/kg N). Additionally, Ca scale was effectively avoided by MCEM. These results demonstrated that FCDI coupled with MCEM could be a promising technology for efficient NH4+ removal, recovery as an ammonia-rich solution and TOC removal from industry wastewaters with alleviation of scaling.

Fabrication and energy efficiency of translucent concrete panel for building envelope

A translucent concrete panel (TCP) is a novel construction material for building envelopes. It combines light conduits, such as optical fibers (OFs), and lightweight, high-strength concrete, enabling it to transmit light and carry the external load. A set of TCPs was cast using OFs with a large diameter (17.8 mm). The compressive strength was 39.6 N/mm2, which is qualified to carry the external load as the structural components. The thermal conductivity of the TCP was 0.2114 W/(m·K), indicating excellent thermal insulation performance compared to traditional building envelopes, such as glass curtain walls (GCW) and masonry facades. To investigate the energy consumption of a TCP, a one-roomed office building was modeled numerically. Three cities were selected to analyze the monetary cost and energy consumption of various building envelopes. These building envelopes were made of a masonry wall, GCW, and TCP. The simulation results revealed that the model with a TCP envelope had the lowest electricity consumption, monetary cost, and payback period. Moreover, it was more energy efficient in Stockholm and Nanjing than in Singapore. The novel TCP is applicable in building envelopes and other areas where light transmission and load-bearing are required.

Spatial and temporal changes in electricity demand regulatory during pandemic periods: The case of COVID-19 in Doha, Qatar

The propagation of the pandemic times, especially during COVID-19, has caused millions of morbidity and mortality cases across the world, forcing people to change their lifestyles and governments to take different measures to slow down the spread of the disease. Consequently, electricity demand and consumption patterns across other socioeconomic sectors were affected by the pandemic. This study aims to investigate the impact of the COVID-19 pandemic on spatiotemporal electricity demand and consumption across six socioeconomic sectors in Doha City, Qatar. The electricity demand and consumption were assessed for three time periods in the pandemic year (pre-lockdown, lockdown, and post-lockdown) compared to electricity consumption prior to the pandemic year (2017–2019). The empirical analysis was performed on a geographically visualized map to determine the areas with high and low electricity consumption. The pattern has been compared before and during the pandemic with previous years. The results show that electricity consumption has increased in the residential and governmental sectors and declined in the industrial and commercial sectors during the lockdown period compared to the post-lockdown period, particularly in the summer season. Mapping the hot/cold spots areas and the temporal analysis of the changing patterns of electricity demand and consumption could provide useful insight to decision-makers for targeted interventions.

Importance of long-term ground-loop temperature variation in performance optimization of Ground Source Heat Pump system

In a recent article published in this journal, a series of design optimization was executed for a ground source heat pump system. The optimization was conducted based on a COPall index, which considers both the hydraulic loss on the buried pipe network, as well as the soil thermal balance over a one-year period. In that article, it was concluded that a borehole spacing of 4 m is the optimal value. In this short communication, the comprehensive COPall index is re-evaluated with the same system setup with both the TRNSYS and OpenGeoSys-TESPy software, but over a 20-year period. The results show that the borehole heat exchanger array with a spacing of 4 m will suffer severe heat accumulation over a 20-year operation. This causes the soil temperature to rise by 5.68 °C, along with a decrease of COPall from 4.59 to 4.18. Due to the smaller increase of ground-loop temperature and lower electricity consumption from heat pumps, a larger spacing of 6 m will bring better COPall value over the long term, and thus should be recommended. The extended numerical study in this work suggests that when evaluating the performance of a ground source heat pump system, different time duration will lead to different results. Therefore, the variation of long-term ground-loop temperature needs to be quantitatively evaluated in advance, and the system optimization is recommended to be conducted over the entire life cycle of the system.

Lifecycle assessment of critical material substitution: Indium tin oxide and aluminum zinc oxide in transparent electrodes

Indium tin oxide (ITO) is the most commonly used transparent electrode (TE) material. However, the supply of indium is at risk due to resource scarcity and geopolitical reasons. Aluminum zinc oxide (AZO) is a potential candidate for its replacement. In this study, a life cycle assessment (LCA) for the substitution of ITO by AZO in an LCD TV was investigated. The main objectives were to (1) evaluate the environmental impacts of substituting ITO by AZO considering their material properties, and (2) propose a new assessment method called the scenario difference method (SDM) to evaluate the environmental impact of material substitution. Using the SDM, the results indicate that it is highly possible to reduce the total environmental burden of an LCD TV by replacing ITO with AZO. The environmental burden in the use stage can be reduced substantially because of the lower electricity consumption of AZO attributed to its higher transparency. • LCA method was developed to evaluate the substitution of ITO by AZO in an LCD TV. • GHG impact of ITO and AZO was estimated considering life cycle stages. • AZO is a viable solution to substitute ITO considering GHG emissions.

Rare earth elements from waste.

Rare earth elements (REEs) are critical materials in electronics and clean technologies. With the diminishing of easily accessible minerals for mining, the REE recovery from waste is an alternative toward a circular economy. Present methods for REE recovery suffer from lengthy purifications, low extractability, and high wastewater streams. Here, we report an ultrafast electrothermal process (~3000°C, ~1 s) based on flash Joule heating (FJH) for activating wastes to improve REE extractability. FJH thermally degrades or reduces the hard-to-dissolve REE species to components with high thermodynamic solubility, leading to ~2× increase in leachability and high recovery yields using diluted acid (e.g., 0.1 M HCl). The activation strategy is feasible for various wastes including coal fly ash, bauxite residue, and electronic waste. The rapid FJH process is energy-efficient with a low electrical energy consumption of 600 kWh ton−1. The potential for this route to be rapidly scaled is outlined.

Рост электропотребления российских регионов как фактор их социально-экономического развития

The indicator of specific (per capita) electricity consumption (SEC) is stabilising in developed countries and increasing in developing economies. At least since the mid-2000s, the difference between the two groups of countries in terms of available power has been decreasing. In contrast to this trend, the transition of Russia to a market economy is characterised by the divergence of regions in terms of SEC. SEC of regions, being on average similar to that of the Netherlands, France, Germany, Great Britain, began to differ by 20 times. The technocenosis theory shows the need to change this negative trend. The low electricity consumption of developing countries depends on their inability to increase its production. In Russia, the problem is due to the low potential of the consumption sector, primarily in regions with SEC below 4 MWh/person per year. The solution of this macroeconomic problem, namely, the reduction of the existing differentiation in regional specific electricity consumption will help maintain the structural stability of the Russian economy and ensure its functioning in the context of external environment changes. Creation of conditions for the energy consumption development in industrial and agricultural enterprises is not a sectoral task of the electric power industry. Considering the sanctions imposed on Russia, structural stability of the national economy can be increased by improving the investment climate resulting from a decline in electricity prices for new non-residential consumers in regions with SEC below the level of developing countries. For these subsidy depending “outsider” regions, an increase in the availability of electricity, rather than the construction of new energy facilities, stimulates the labour productivity growth, re-industrialisation, and emergence of growth points.

Clean preparation of V2O3 by one-step molten salt electrochemical reduction of soluble NaVO3

Vanadium oxides, such as V2O5 and V2O3, are important metallurgy products and mainly used to prepare V-based alloys for steelmaking. At present, vanadium oxides are mainly produced by complex sodium salt roasting process. Serious environmental pollution, such as emission of ammonia nitrogen wastewater and NH3, are restrictive problems. Here, a clean and sustainable method for V2O3 preparation is proposed by one-step molten salt electrochemical reduction of soluble NaVO3, i.e. an indispensable intermediate in traditional V metallurgy. The pollution issues are well solved. The theoretical decomposition voltages of different vanadate to various low-valence vanadium oxides were calculated. NaVO3 with a solubility of 14.7 wt% is the most suitable vanadate for the direct preparation of V2O3 by molten salt electrolysis. The effects of cathode structure, NaVO3 content, electrolysis temperature and voltage on current efficiency and electricity consumption were systematically studied. High-purity V2O3 with uniform particle distribution is obtained and the lowest electricity consumption is only 2.86 kWhkg−1. V2O3 is mainly produced by one-step electrochemical reduction of soluble NaVO3 through two-electron transfer process. The economic evaluation for ferrovanadium production is preliminarily carried out. Compared with the traditional process, the cost for ferrovanadium production is lower by the aluminothermic reduction of V2O3 which is prepared by clean one-step electrolysis of soluble NaVO3.

Experimental assessment of a pilot scale hybrid cooling system for water consumption reduction in CSP plants

The new challenge of the European Commission is to limit water consumption in Concentrating Solar Power (CSP) plants, especially significant in the cooling process. Hybrid cooling systems are presented as a potential solution to achieve water consumption reduction since they also avoid a high penalty of efficiency loss in the power block. In this work, a hybrid cooling pilot plant installed at Plataforma Solar de Almería is evaluated experimentally. The system has been tested under different ambient and operating conditions to analyze their influence on the water and electricity consumption. The results reveal that significant water savings were achieved in comparison with the conventional only-wet configuration. Concretely, a maximum water consumption saving of 67% was found at high ambient temperatures (between 25 and 30 °C) and for a thermal load of 80% when a hybrid configuration was used. The optimal operating strategies that achieve a tradeoff between low water and electricity consumption have been identified by two efficiency indexes: the specific electricity and water consumption. The parallel configuration was the optimal one in most of the cases. At high ambient temperatures and 80% thermal load, the electricity and water consumptions of this configuration were 0.033 kWe/kWth and 0.071 L/kWth, respectively.

10 Gbit s−1 Free Space Data Transmission at 9 µm Wavelength With Unipolar Quantum Optoelectronics

AbstractFree space optics data transmission with bitrate in excess of 10 Gbit s−1 is demonstrated at 9 µm wavelength by using a unipolar quantum optoelectronic system at room temperature, composed of a quantum cascade laser, a modulator, and a quantum cascade detector. The large frequency bandwidth of the system is set by the detector and the modulator that are both high frequency devices, while the laser emits in continuous wave. The amplitude modulator relies on the Stark shift of an absorbing optical transition in and out of the laser frequency. This device is designed to avoid charge displacement, and therefore it is characterized by an intrinsically large bandwidth and very low electrical power consumption. This demonstration of high‐bitrate data transmission sets unipolar quantum devices as the most performing platform for the development of optoelectronic systems operating at very high frequency in the mid‐infrared for several applications, such as digital communications and high‐resolution spectroscopy.

The effect of conservation on residential electricity consumption: evidence from Kuwait

ABSTRACT Based on data from a household survey completed in 2016, this paper estimated a model for residential electricity consumption in Kuwait. The main objective of estimating the model was to examine the impact of curtailment and efficiency energy conservation measures on household electricity consumption. Given Kuwait’s demographic composition and variations in electricity consumption across months, the model was estimated for two population groups (nationals and expatriates) and three periods (annual, summer months, and winter months). Prior to estimating the model, tests were conducted to determine if the observed differences in consumption across the population groups were sufficiently different to warrant separate treatment of groups. The survey data revealed that despite electricity consumption being heavily subsidized, households made efforts to conserve electricity by investing in efficient technologies as well as changing habits and practices. While the curtailment measures reported to be adopted by households were found to lower electricity consumption of the national households, the efficiency measures were found to impact electricity consumption of expatriate households. Awareness of conservation campaigns and conservation issues were found to lower electricity consumption, particularly in the case of expatriate households.

Electrodeposited PdNi on a Ni rotating disk electrode highly active for glycerol electrooxidation in alkaline conditions

The development of alcohol-based electrolysis to enable the concurrent production of hydrogen with low electricity consumption still faces major challenges in terms of the maximum anodic current density achievable. Whilst noble metals enable a low electrode potential to facilitate alcohol oxidation, the deactivation of the catalyst at higher potentials makes it difficult for the obtained anodic current density to compete with water electrolysis. In this work the effect of significant parameters such as mass transport, glycerol and OH− concentration and electrolyte temperature on the glycerol electrooxidation reaction (GEOR) in alkaline conditions on a bimetallic catalyst PdNi/NiRDE (Pd0.9Ni0.1) has been studied to discern experimental conditions which maximise achievable anodic current density before deactivation occurs. The ratio of NaOH:glycerol in the electrolyte highly affects the rate of the GEOR. A maximum current density of 793 mA cm−2 at -0.125 V vs. Hg/HgO through steady state polarisation curves was achieved at a moderate and intermediate rotation rate of 500 RPM in a 2 M NaOH and 1 M glycerol (ratio of 2) electrolyte at 80 °C. Shown here is a method of catalyst reactivation for enabling the long-term use of the PdNi/NiRDE for electrolysis at optimal conditions for extended periods of time (3 h at 300 mA cm−2 and 10 h at 100 mA cm−2). Through scanning electron microscopy (SEM), X-ray photon electron spectroscopy (XPS) and X-ray diffraction (XRD) it is shown that the electrodeposition of Pd and Ni forms an alloy and that after 10 h of electrolysis the catalyst has chemical and structural stability. This study provides details on parameters significant to the maximising of the GEOR current density and the minimising of the debilitating effect that deactivation has on noble metal based electrocatalysts for the GEOR.

Solar-assisted electrooxidation process for enhanced degradation of bisphenol A: Performance and mechanism

Comparisons of solar-assisted electrooxidation process (SEOP), electrooxidation (EO), and solar photolysis have been addressed to evaluate the performance of bisphenol A (BPA) removal and mineralization. The results presented the BPA removal efficiency of 100% in SEOP was higher than that of 2.8% and 88% at 90 min in direct photolysis and EO process, respectively, indicating the synergistic effect of EO and solar light in SEOP. The investigation of corresponding active species indicated that ·OH and 1O2 played the predominant role in SEOP. The introduction of solar light in the EO process could promote the generation of ·OH, 1O2, and SO4·- and enhance the degradation performance, explaining the synergistic removal mechanism. The density functional theory (DFT) results pointed out the main active sites of BPA attacked by electrophilic reagent based on the calculation of the energy barrier, Fukui index, and molecular orbitals, etc. Taking into account of the identification of intermediates, the possible degradation pathways of BPA mainly included C-C bond cleavage, ring hydroxylation, and ketonization process. The effects of anode materials, illumination intensity, current density, and electrolyte for the degradation efficiency in SEOP were explored. These results exhibited that the efficient removal of BPA in SEOP was achieved with a relatively lower electricity consumption of 1.21 kWh·(m3·order)-1, which provided new insights into the synergistic mechanism and enhanced removal of contaminants.

Numerical design and optimization of a high compact, broadband optical three-mode selective converter by manipulating ITO-based controllable phase shifters integrated on silicon-on-insulator waveguides

Recently, indium tin oxide has been very attractive for thermo-optic (TO)-controlled silicon photonic devices, due to its high transparency, strong TO phase dependency, high conductivity, and CMOS compatibility. These properties enable the reduction of the gap between the silicon core and the heater, leading to a considerably low electric power consumption and high switching speed. We present an investigation of a numerical simulation to design and optimize a compact ITO microheater for tuning the TO phase shift in a proof-of-concept of a three-mode converter (TMC) with broadband and ultralow loss properties. We show that the TMC can operate the 3-dB bandwidth up to 100 nm. In addition, the designed device can attain relatively large fabrication tolerances for width and height of ±50 and ±5 nm, respectively. In addition, the proposed mode converter consumes a total power of less than 90 mW and obtains a fast switching time of less than 8 μs. Moreover, the device can be integrated into an estimated compact footprint of 8 μm × 2160 μm. Such excellent performances make ITO a strong candidate for low-loss TO phase shifters and open up an alternative method for realizing ultrafast and high-speed mode division multiplexing systems and large-scale applications.

Influence of various chilling methods on the sustainable beef production based on high voltage electrical stimulation.

Among the challenges of sustainable management of meat production, the key issue is to improve the energy efficiency of production processes, which will consequently affect the reduction of greenhouse gas emissions. Such effects are achieved by combining various chilling systems with electrical stimulation that determines the quality of meat at the slaughter stage. The novelties of the research undertaken included determining the impact of various variants of meat production (chilling method: slow, fast, accelerated + HVES/NES) on changes in the basic (industrial) quality indicators (pH and temperature) of beef produced from Polish Holstein-Friesian breed cattle, and then indicating the optimal variant for energy-efficient (sustainable) beef production. The HVES and the fast chilling method yielded positive economic (meat weight loss), technological (high quality, hot-boning), energetic (lower electricity consumption), and organizational effects (reduced chilling and storage surfaces and expenditures for staff wages) compared to the slow and accelerated methods. Reaching the desired final temperature with an increased amount of chilled meat enables obtaining a few-fold decrease in the specific energy consumption and a higher energy efficiency of the process. This allows recommending the above actions to be undertaken by entrepreneurs in the pursuit of sustainable meat production.

On the relevance of values, norms, and economic preferences for electricity consumption

Based on data of more than 3700 citizens in Germany, this paper empirically examines the relevance of several groups of explanatory factors for electricity consumption. Besides controlling for individual housing and dwelling characteristics as well as socio-demographics, we analyze the effect of environmentally-related values and norms. Since behavioral economics reveals the importance of economic preferences for many individual activities, we additionally consider time and risk preferences, altruism, trust, and reciprocity in our econometric analysis. With respect to the latter factors, only patience has a significantly negative effect on electricity consumption. Instead, our estimation results suggest a high relevance of several individual housing and dwelling characteristics and socio-demographics. The most interesting result is probably that neither environmentally-related values such as ecological policy identification and environmental awareness nor environmentally-related personal and social norms have a significant effect. In contrast to the USA and to the demand for green electricity in Germany, these estimation results suggest that citizens with strong environmentally-related values and norms in Germany do not consider low electricity consumption as an important direction for environmental and climate protection.

Effect of Metal Additives in the Bed on the Performance Parameters of an Adsorption Chiller with Desalination Function

Adsorption chillers with desalination functionality, being devices characterised by very low electricity consumption, provide an alternative to conventional sources of cooling and water. The option of desalinating water means that the use of a single device enables obtaining two useful products. Adsorption chillers are not widely used at present. due to their low performance characteristics; these are, however, constantly being improved. This paper presents a verification of the possibility of increasing the cooling coefficient of performance (COP) and specific cooling power (SCP) of a laboratory adsorption chiller by optimising the length of cycle times and using a copper additive to silica gel with a mass fraction of 15% to increase heat transport in the bed. The choice of copper among other considered additives was determined by the conclusions from the research on the sorption kinetics of various mixtures, price and availability, and a high thermal conductivity. The device was operated in a two-bed mode aimed at producing cooling. The adsorbate was distilled water. The results were compared with those obtained under similar conditions when the beds were only filled with silica gel. As a result of the testing, it was found that the use of the copper additive with the sorbent increased both the COP and SCP. The tests were performed for different cycle times, of 100, 200, 300 and 600 s. With increasing cycle time COP also increased. In contrast, the specific cooling power increased only up to a certain point, whereafter its value decreased.

Study Results and Obtaining High Ventilation Air Quality in Architecture for an Old Shopping Centre Public Utility Building with Modernised EL. Heating in Warsaw, District, Poland

The subject of this paper is the study of a public utility building, a shopping centre in Warsaw/Targówek, carried out as part of the programme of “Research for obtaining high air quality in architecture. The purpose of the study of the building is to utilise a new technology which will lead to reductions in electrical and heat energy consumption and cuts in CO2 emissions in the modernised Shopping Centre Public Utility Building in Warsaw. The building is equipped with systems for obtaining heat and cold from groundwater and is adapted to a low electrical energy consumption level with the lowest primary energy ratio in Poland. It is located in Warsaw and, in addition to the energy sourcing system, features a highly modern control system (BMS). The objective of the study is to demonstrate operating costs for a building with low exterior wall and roof insulation parameters. In addition, the building uses a heating system based solely on electrical heating due to its lack of access to gas and district heating. The conducted studies and analyses allowed a comparison of the operating costs of old buildings following modernisation with those of new buildings.