Reduce Electricity Consumption Research Articles

Heterostructured FeP4/CoP@NF as trifunctional electrocatalysts for energy-efficient hydrogen production

The developing of efficient and cost-effective electrocatalysts for hydrogen evolution is of great significance to the development of hydrogen energy. It is believed that the efficient hydrogen generation of water cracking is restricted from the slow oxygen evolution reaction (OER) process. Consequently, it is highly recommended to find alternative anodizing to produce hydrogen to reduce electricity consumption. Urea oxidation reaction (UOR) is an alternative to the traditional anodic OER. In this paper, an electrocatalyst FeP4/CoP@NF-7.5 supported on nickel foam (NF) was designed by using a template-directed growth and low-temperature phosphating method. The FeP4/CoP@NF-7.5 with a rich interface gives it more active sites and enhances mass transfer and conductivity, possessing excellent catalytic performance against hydrogen evolution reaction (HER), OER and UOR in alkaline electrolyte. Thanks to the abundant interface and bimetallic synergy, the designed catalyst exhibits the overpotentials of 45 mV and 259 mV for HER and OER to transfer 10 mA cm−2. In addition, FeP4/CoP@NF-7.5 also possesses significant catalytic activity against UOR of 136 mV (j10) in 1 M KOH with 0.33 M urea, which provides another alternative to the low efficiency of OER through the reduction of hydrogen production costs. Finally, the overall water splitting test was undertaken in 1 M KOH containing/free of 0.33 M urea. Remarkably, only 1.43 V is required to drive on urea electrolyzer (j10 = 10 mA cm−2), while 1.52 V are gained on water electrolyzer. This paper lays the foundation for the developing of high-active transition bimetallic phosphide electrocatalysts for energy-saving hydrogen production.

HIGHLY EFFECTIVE DIRECT CONTACT HUMIDIFIER FOR THERMAL DESALINATION SYSTEM

The aim of the work is to increase the efficiency of thermal desalination systems with a humidification-dehumidification air cycle due to the reduction of electricity consumption. The most common designs of heat exchangers for air humidification have significant aerodynamic and hydraulic drops. To eliminate this disadvantage, it is proposed to use the internal volume of the vertical tube as an active heat and mass transfer zone during moisture evaporation from salt water to air. The operation of such desalination system has been mathematically modeled and its energy characteristics were determined. A special feature of the mathematical model is the consideration of heat and mass transfer equations for the humidifier and dehumidifier. The effective air velocity in the tube is 3 m/s. Effective operation of thermal unit with a film humidifier is possible then air mass flow is equal to the salt water flow. In this case, the geometric dimensions of the tube must be within the following limits: diameter 20...30 mm, height 2...2.5 m. The conducted mathematical modeling and obtained results give reasons to assert, that for the same rate of evaporation, the film heat exchanger has the lowest aerodynamic and hydrodynamic drops compared to other types of humidifiers. The use of such direct contact device will lead to a decrease in the electricity consumption necessary for salt water and air circulation in the humidification-dehumidification thermal installation.

Field Experimental Evidence on the Effect of Pricing on Residential Electricity Conservation

This study examines how electric utilities and regulators can encourage residential consumers to conserve electricity during the hottest summer days and shift electricity load from the day to off-peak, nighttime hours. We analyze a two-year field experiment involving 280 Texas households that explores approaches to conservation and load-shifting to enable emission reductions and reduce generation costs. Our critical peak pricing intervention reduces electricity consumption by 14% on the peak hours of the hottest days, leading to greenhouse gas emission reductions of about 16%. A key contribution of this study is the use of high-frequency appliance-level data. We show that 74% of the critical peak response is from reducing air conditioning. In a complementary nighttime pilot program, consumers respond strongly to lower prices by programming the timing of electric vehicle charging. Our work highlights how automation can influence the consumer tradeoffs relating to effort costs, discomfort, monetary incentives, and warm glow. This paper was accepted by Rajesh Chandy, Special Section of Management Science on Business and Climate Change. Supplemental Material: The data and online appendices are available at https://doi.org/10.1287/mnsc.2020.02074 .

CFD simulation and optimization of an industrial cement gas–solid air classifier

An air classifier is one of the main and effective devices in cement industry. In this study, a three-dimensional, steady and two-phase (solid-gas) computational fluid dynamics (CFD) simulation was performed to optimize the performance of this device in the Kerman Momtazan cement plant, Iran. After the validation of CFD results, the air flow field and air path lines between fixed blades were checked carefully and the non-uniformity in velocity distribution and the formation of vortex flows between the blades close to particle inlets were observed. The study tried to improve the device efficiency by changing the method of entering particles into the device, resulting in a reduction in air classifier electrical energy consumption (from 41 to 35 (kW h)/t) and an increase in production rate (from 203 to 214 t/h). Additionally, the study investigated the effects of other modifiable operating conditions like rotary cage rotation speed, pressure difference, and inlet air temperature on the particle size distribution and classifier efficiency. The results showed that increasing the cage rotation speed decreased the product rate and the product particles mean diameter while increasing pressure difference or increasing temperature increased the product rate and the product particles mean diameter. It was concluded that these modifiable operating conditions can significantly affect the performance of the air classifier in the cement industry.

Energy efficiency of commercial offices by luminous retrofit

Lighting is one of the systems that mostly consume electricity in commercial buildings. Therefore, improving its efficiency has the potential to reduce electricity consumption and emission of polluting gases. The objective of the present study was to assess an office lighting system retrofit of an existing building from the 1990s, verify the light levels in relation to standards of the Brazilian requirements, and to explore new systems with potential for luminous and energy improvement. The analyzes were carried out through computer simulations using the DIALux evo software, which allows the evaluation of artificial and natural illuminations simultaneously. The results indicated that the existing lighting system does not meet the average illuminance standard value for office environment. From simulations with new arrangements and types of luminaires and lamps, two more efficient lighting systems were designed. The first presented savings of 15.5% in lighting energy when replacing T12 fluorescent lamps with LED luminaires. The second system considered the use of natural light and was complemented by artificial lighting with the aid of a dimming system linked to the availability of daylight, and presented up to 67% less electric energy consumption when compared to the existing lighting system in the environments. Therefore, it was possible to propose actions to the existing lighting system retrofit and, thus, offer better visual comfort to users and at the same time save energy.

DEVELOPMENT AND CONFIGURATION OF A FULL-ORDER OBSERVER FOR «CABLE LINE – INDUCTION MOTOR» ELECTRICAL COMPLEX

Link for citation: Rakov I.V., Glazyrin A.S., Kladiev S.N. Development and configuration of a full-order observer for «cable line – induction motor» electrical complex. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 219-231. In Rus. The relevance. The task of oil production specialists is to minimize all types of energy consumption, ensuring an increase in oil production profitability because of the following reasons. First of all, availability of oil reserves with low energy consumption decreases, and the number of gushing wells reduces, along with increase in water content in the extracted liquid. One of the methods of reducing energy consumption in wells with low and moderate flow rate, equipped with electric submersible pumps, is a well transfer from continuous to periodic operation mode, namely cyclic well operation. This involves alternating short periods of oil production (up to 15 minutes) with liquid accumulation (up to 30 minutes) in the wellbore. Well switching to a cyclic operation mode leads to a 40 % reduction in electric power consumption by the submersible electric motor, as well as increase in oil production up to 3 %. This can be achieved by partial gravitational separation of the extracted liquid at the accumulation stage. However, a negative consequence of switching to a cyclic operation mode is a reduction in an average time between failures. This is due to increase in current surges and torque during rapid acceleration of the submersible electric motor to the rated speed. Transition from a scalar control system with an open loop to a vector control system without sensors can settle these problems. To implement a vector control system, it is necessary to obtain information about the state variables of a submersible electric motor. Construction of a full-order observer based on explicit mathematical models is considered as a promising method of obtaining information, taking into account the main advantages and disadvantages of direct measurement and indirect estimation of state variables. Based on the above, the urgent task is to develop a full-cycle observer for the electromechanical complex «cable line – induction motor» and a methodology for its configuration. The settlement of this issue will create prerequisites for implementation of a vector control system by a submersible electric motor. The main aim: to develop and experimentally validate the effectiveness of a full-order observer for the electrical complex «cable line – induction motor» using voltage and current measurements at a cable line input. Methods: literature analysis, system analysis, mathematical modeling, experimental research. Results. The authors have developed and tested a full-order observer for the «cable line – induction motor» electrical complex. The results of this study confirm the efficiency of the developed observer and its potential applicability for implementing a vector control system for electric submersible pumps. Ultimately, this will enable the transition of low- and medium-flow-rate oil wells to a cyclically operated mode without a significant reduction of the mean time between failures.

Renovation of an Academic Building’s Envelope, Lighting, and Air Conditioning System According to Thailand Building Energy Code for Energy Consumption Reduction

This study evaluated the feasibility of building renovation with regard to the aspects of economy and energy. An academic building located in Bangkok, Thailand was selected for a case study. Four sub-systems, namely, the building envelope, lighting system, air conditioning unit, and electrical system, were renovated. From the energy perspective, Thailand’s Building Energy Code was used as an evaluating standard, and the BEC software (Version 2.6.0) was employed for the calculations. The economic feasibility of the renovation was determined on the basis of the internal rate of return and discounted payback period. It was demonstrated that the renovation can result in a reduction in the annual energy consumption of the entire building by up to 55.44%. In regards to economic feasibility, the renovation project can achieve a payback period of 4.98 years with 20.89% IRR. In addition, the renovation of a building can lead to spare capacity of the transformer for electric vehicle charger loads. Thus, the renovation of an old building into an energy-efficient building in compliance with building code can afford benefits both in terms of electricity consumption reduction and decreased energy cost for the project owner and provide opportunity for the building to support future load.

Method for ensuring the safety and effectiveness of wastewater treatment under centralized treatment mode by using a petrochemical park as case study

With the requirement of green development of industry and to achieve the synergistic effect of pollution reduction and carbon reduction in wastewater treatment, more and more industrial parks will treat wastewater by using centralized mode. How to effectively avoid risks including penetration, interference, dilution, and excessive emissions of pollutants discharge during the centralized wastewater treatment process has become an urgent problem to be solved. To ensure the safety and effectiveness of wastewater treatment, a method was established for industrial parks in this study by considering some factors such as the treatability of pollutants, the allowable pollutant discharge, the detection limit of the analysis method and the treatment load of the centralized wastewater treatment facility comprehensively. Taking a petrochemical park in East China as an example, the method was applied to identify 28 of 35 characteristic pollutants can be centrally treated. Benefit analysis shows the centralized wastewater treatment mode can not only ensure that the discharged wastewater meet requirements of emission limits, but also greatly save the cost of wastewater treatment for enterprises and help reduce electricity consumption as well as carbon emissions. Sufficient attention must be paid to the evaluation of the effectiveness and safety of centralized wastewater treatment in the future.

The Net Zero Emissions Decision Model of the Sustainable Path of Chinese Business Parks

Business parks account for 30% of China’s total carbon emissions. Exploring emissions reduction approaches for business parks is crucial to achieve a net-zero emissions target, as well as for achieving a representative example for all types of emissions entities. Business parks mainly adopt two types of emissions reduction approaches: energy-saving renovations and purchasing carbon reduction products. However, there are limited studies focusing on the optimal combinations of the two approaches for reaching net-zero emissions and evaluating the cost effectiveness. To find a feasible and quantified way to build net-zero business park, a comprehensive path decision model is proposed. The problem is broken down into two parts: the optimal carbon reduction portfolio and the optimal electricity saving were researched. For the optimal product portfolio, the Markowitz theory is employed to balance the risk of carbon reduction products with the expected cost. In the part of optimal electricity saving, considering a ten-year life cycle, the total cost includes renovation investment, carbon reduction products cost, and cost saving of electricity consumption reduction. Based on the energy consumption, technical, and price data, the combination of energy-saving renovations and carbon reduction products is optimized. The model suggests a business park can save 24% of energy consumption through renovation investment and purchase CCER as 66% of the carbon reduction product portfolio. Taking only purchasing carbon reduction products as a benchmark to assess economic efficiency, implementing an optimized level of energy-saving renovation is found to save 16% of the comprehensive cost for the life cycle required to achieve zero carbon emissions. This model provides a new comprehensive optimization idea that will help future parks make decisions to achieve zero-carbon emission targets.

High-Performance Alkaline Seawater Electrolysis with Anomalous Chloride Promoted Oxygen Evolution Reaction.

A highly selective and durable oxygen evolution reaction (OER) electrocatalyst is the bottleneck for direct seawater splitting because of side reactions primarily caused by chloride ions (Cl-). Most studies about OER catalysts in seawater focus on the repulsion of the Cl- to reduce its negative effects. Herein, we demonstrate that the absorption of Cl- on the specific site of a popular OER electrocatalyst, nickel-iron layered double hydroxide (NiFe LDH), does not have a significant negative impact; rather, it is beneficial for its activity and stability enhancement in natural seawater. A set of in situ characterization techniques reveals that the adsorption of Cl- on the desired Fe site suppresses Fe leaching, and creates more OER-active Ni sites, improving the catalyst's long-term stability and activity simultaneously. Therefore, we achieve direct alkaline seawater electrolysis for the very first time on a commercial-scale alkaline electrolyser (AE, 120 cm2 electrode area) using the NiFe LDH anode. The new alkaline seawater electrolyser exhibits a reduction in electricity consumption by 20.7 % compared to the alkaline purified water-based AE using commercial Ni catalyst, achieving excellent durability for 100 h at 200 mA cm-2.

High‐Performance Alkaline Seawater Electrolysis with Anomalous Chloride Promoted Oxygen Evolution Reaction

AbstractA highly selective and durable oxygen evolution reaction (OER) electrocatalyst is the bottleneck for direct seawater splitting because of side reactions primarily caused by chloride ions (Cl−). Most studies about OER catalysts in seawater focus on the repulsion of the Cl− to reduce its negative effects. Herein, we demonstrate that the absorption of Cl− on the specific site of a popular OER electrocatalyst, nickel‐iron layered double hydroxide (NiFe LDH), does not have a significant negative impact; rather, it is beneficial for its activity and stability enhancement in natural seawater. A set of in situ characterization techniques reveals that the adsorption of Cl− on the desired Fe site suppresses Fe leaching, and creates more OER‐active Ni sites, improving the catalyst's long‐term stability and activity simultaneously. Therefore, we achieve direct alkaline seawater electrolysis for the very first time on a commercial‐scale alkaline electrolyser (AE, 120 cm2 electrode area) using the NiFe LDH anode. The new alkaline seawater electrolyser exhibits a reduction in electricity consumption by 20.7 % compared to the alkaline purified water‐based AE using commercial Ni catalyst, achieving excellent durability for 100 h at 200 mA cm−2.

Hydrothermal bio-char as a foaming agent for electric arc furnace steelmaking: Performance and mechanism

Electric arc furnace (EAF) foaming agent protects the furnace lining, reduces electricity consumption, and shortens smelting time in steelmaking process. Carbon-neutral EAF foaming agents with satisfactory foaming performance are of great significance for energy-saving and emission reduction in EAF steelmaking. In this study, effects of hydrothermal variables on the foaming performance of EAF slag with bio-char and the associated mechanism were investigated. Meanwhile, the existing method for evaluating EAF slag foaming performance was upgraded, by developing a real-time, dynamic and accurate monitoring method. It was demonstrated that effects of hydrothermal variables on EAF slag foaming with the resultant bio-char followed the order of hydrothermal temperature > solid/liquid ratio > agitation speed > residence time. A combination of hydrothermal temperature at 280 °C, residence time for 4 h, agitation speed at 1050 r/min, solid/liquid ratio of 1:30 resulted in bio-char as the foaming agent with the effective foaming time up to 353 s, much higher than that of fossil derived foaming agent (219 s). When applied with EAF slag for foaming, the porous structure of bio-char contributed to a more constant slag viscosity at 0.30–0.32 Pa‧s, and a decelerated reduction of surface tension, which effectively extended the foaming time and stabilized the foaming performance. The application of bio-char also led to a more complete reaction in EAF in a shorter time. Bio-char obtained via hydrothermal carbonization of pine sawdust performed satisfactorily as an EAF foaming agent and it is advantageous over the fossil derived foaming agent.

Optimum window-opening control for naturally ventilated buildings with phase change materials in the hot and humid climate of Indonesia

This study aims to determine the optimum window-opening control that maximizes annual thermal comfort using ventilative cooling, i.e., night and comfort ventilation, in naturally ventilated buildings where phase change materials (PCMs) are used. A thermal energy simulation (TES) coupled with an airflow network model was constructed to evaluate the comfort ventilation and thermal storage effects of the PCMs by controlling the window-opening patterns. The EnergyPlus-based coupled TES model was validated by comparing with the field measurement results of a full-scale experimental building in Indonesia. The root-mean-square errors of the temperature and air speeds at the center of the target building ranged from 0.2 to 0.5 °C and 0.1–0.2 m/s, respectively. The accuracy of the coupled TES was similar to that of computational fluid dynamics coupled with the heat balance analysis, which can simulate the spatial distributions of temperature and air speeds. The annual simulation results showed that prioritizing the thermal storage effect of the PCMs in the morning and comfort ventilation in the afternoon increases the thermal comfort period. For the optimum window-opening control to maximize thermal comfort in the hot and humid climate, an indoor temperature of 27 °C can be considered a criterion to open the windows for comfort ventilation in addition to night ventilation for the thermal storage effect. When this criterion was applied, the thermal comfort period in the room with PCMs increased to 83.3 %. Accordingly, the reduction in electricity consumption for space cooling was 41 % less than that in a control room without PCMs.

Automação de irrigação de lavouras de arroz usando controlador fuzzy e previsão meteorológica

ABSTRACT This paper presents a new irrigation controller based on fuzzy logic that uses weather forecast data and crop characteristics to evaluate the real-time need for irrigation of rice crops and to increase the efficiency of irrigation systems. Tests were performed with real data obtained from three different crop fields in Rio Grande do Sul State, Brazil, and on four meteorologically different days of the 2021/2022 harvest to demonstrate the ability to reduce power consumption for irrigation; the power consumption on days of heavy precipitation was above 80% under all simulated conditions. Depending on the size of the crop and the tested meteorological conditions, the minimum reductions in energy consumption were between 33-66% on dry days with no precipitation forecast. More than 15% reduction in the flow of the water catchment was also observed, even in the most adverse farming scenarios. This study reveals the necessity for technological advances in rice-crop irrigation systems to increase the efficiency of flood irrigation in large areas for reducing electricity consumption, increasing the profitability of rural producers, and ensuring the preservation and availability of water resources.

Assessment of electricity consumption reduction potential for city-scale buildings under different demand response strategies

Assessment of electricity consumption reduction potential for city-scale buildings under different demand response strategies

Towards Using MMO Anodes in Zinc Electrorefining: Mn Removal by Simulated Plant Off-Gas

Implementing mixed metal oxide (MMO) anodes in zinc electrowinning is highly desired due to the considerable reduction in electrical energy consumption. However, the presence of manganese in the electrolyte is a major obstacle for implementing MMO anodes in the zinc cell houses. In this work, we explore the possibility of using plant off-gas, containing SO2, to remove manganese. A SO2/air gas mixture with different SO2 and O2 concentrations was therefore used for the oxidative precipitation of manganese. It was shown that the manganese oxidation reaction is highly pH-dependent. Calcium hydroxide was used to control the pH during the process. Different operating parameters, i.e., pH, SO2/air ratio, reaction time, and effect of cobalt as a reaction catalyst, were investigated. Optimal conditions for manganese removal were reported. Under the optimal conditions, the manganese concentration decreased from 1 g L−1 to less than 1 mg L−1 within 30 min. Precipitates were characterized using EDS, XRF, and XPS techniques and showed coprecipitation of manganese, zinc, gypsum, and cobalt.

Studi Perencanaan Ulang Perpipaan Sistem Filtrasi Air Skala Rumah Tangga

Clean water is a primary necessity for human survival, but due to limited access to clean water sources, wells are often used to meet this need. However, water from wells cannot be used directly because its quality varies depending on the soil conditions. Due to these differences, a filtration system needs to be installed in the treatment of raw water from the well. In the process, well water, after being processed through the filtration system, experiences a decrease in flow rate before being stored in water tanks. This creates a problem, namely excessive electricity consumption and insufficient water flow for household use. In this research, the researcher attempts to implement the SNI (Indonesian National Standard) standards in household-scale clean water treatment, whereas previous research focused more on water quality testing. The objectives of this research are to reduce electricity consumption and increase water flow to meet household needs.
 Regarding the research method, the researcher conducted a literature review, data collection, pre-improvement testing, redesigned pipeline planning, performance testing of the improvement results, and analysis of the outcomes. The results of this research show that for the 1-liter container testing, the required time has increased, with the fastest time being 6.4 seconds and the slowest being 6.7 seconds, compared to the initial testing, which had a range of 13.2 seconds to 13.6 seconds. As for electricity consumption, there has been a significant decrease, from 2.76 A in the initial testing to 1.76 A, resulting in an average power consumption of 200.3 watt, compared to the previous 603.7 watt.

Light Energy Efficiency in Lettuce Crop: Structural Indoor Designs Simulation.

Indoor agricultural offers efficient alternatives for intensive food production through automation technologies and controlled environments. Light plays a crucial role in plant development; however, photons captured by the crop are often wasted in empty spaces, resulting in low light efficiency and high energy costs. This research aims to simulate eight structural designs for an indoor lettuce crop, exploring different planting systems and light and culture bed combinations (static and mobile) to identify the most effective mechanism for light efficiency during crop growth. The simulations were carried out with spreadsheets based on applying formulas of yield in dry biomass per photosynthetic photons, lighting costs, harvest, and production. The results indicate that Circular Moving Light and Mobile Culture Bed with Quincunx Planting (CML-QM) and Circular Moving Light and Mobile Culture Bed with Linear Planting (CML-LPM) exhibit higher photon capture percentages (85% and 80%, respectively) and lower electricity consumption compared to static designs. The simulation results demonstrate the potential for significant improvements in photon capture and cost savings through optimized system designs. This investigation provides valuable insights for designing more efficient systems and reducing electricity consumption to enhance the capture of photosynthetic photons in indoor lettuce cultivation.

Embedded System for Learning Smooth and Energy-Efficient Tram Driving Techniques

Driving a tram in city traffic is a challenging task. It is especially difficult to drive smoothly (without unnecessary jerks) when the route runs through streets with many other vehicles, pedestrians, and traffic lights. A smooth driving style of the tram driver not only has a significant impact on the comfort of passengers being transported, but also affects the energy consumption of the tram. The paper focuses on the analysis of the tram driver’s way of driving and the resulting energy savings. The energy consumption of the tram was measured depending on the driver’s driving technique. For the analysis of the driving technique, an innovative electronic device was proposed to be installed on the tram. It detects jerks in the lateral and longitudinal directions. Based on vibration analysis, it evaluates the driver’s driving technique on an ongoing basis and displays the result of this assessment. The device is cheap and uses a popular minicomputer, a GPS system receiver, an IMU accelerometer, and a screen. It is independent of the electronic systems of the tram. Due to this, it is possible to increase passenger comfort and reduce electricity consumption. It can be useful when learning to drive a tram. Preliminary tests of this device were carried out on a real tram during rides with passengers in city traffic. Tests have confirmed its effectiveness.

System of mutual loading of auxiliary electric machines with coverage of losses from mechanical power sources

Purpose. Increasing the level of safety and reducing the cost of rolling stock maintenance is an urgent problem for Ukrainian railways today. Existing test benches for auxiliary machines are usually built according to the scheme with direct loading of the tested electric machine and do not meet modern requirements for the quality and energy efficiency of testing. In this regard, there is a need to design energy-efficient test benches for testing auxiliary machines of electric rolling stock. Methodology. To achieve this goal, we used an analytical method of research to determine the optimal structure of the test bench. The paper considers the voltage balance diagram in the mutual load system. Separately, the calculations are presented, on the basis of which the design diagrams of the electrical and mechanical parts of the test bench are constructed, and the conditions for covering all losses in the mutual load system are determined using the design diagrams. Findings. In the course of the research, the power balance equation in the mutual load system was obtained. On the basis of the equations, a model of a mutual load system with coverage of all losses from a single source of mechanical power was built. The main advantage of the developed model is that it can be implemented both by numerical calculations using composite systems of equations and by object-oriented programming in specialized software systems. Originality. A rational scheme for testing auxiliary machines with the coverage of losses from a single source of mechanical power is proposed. The use of a single power source can significantly reduce the additional consumption of electrical energy due to the more efficient use of auxiliary equipment, in particular, a mechanical power source. Practical value. Based on the results obtained, it is possible to determine the parameters of the scheme for testing auxiliary machines at the design stage of the test bench. Implementation of the research results at auxiliary machine repair enterprises will reduce electricity consumption for post-repair testing due to the higher energy efficiency of the test scheme.