Electricity Savings Research Articles

Systematization of Material Flows of Natural and Secondary Raw Materials of Phosphorus Industry of the Republic of Kazakhstan

Abstract The production of elemental phosphorus is a material- and energy-intensive process, which makes it important to improve the technology in order to maximize savings of raw materials and electricity. At the enterprises of the phosphorus industry of Karatau-Zhambyl TIC (territorial-industrial complex) there is an incomplete use of production capacity, which is due both to organizational reasons, and largely due to the properties of commercial phosphorites of the Karatau basin. The decisive factor is the use of mine phosphate rock fines and waste from Karatau-Zhambyl TIC and phosphate plants, previously sent to the dumps. The system approach to the study of interaction of the chemical enterprise with the environment allowed to present mineral flows in the system, accumulation and transformation of matter in the constituent blocks-systems in a new way, to offer a new methodological approach to the system management based on the analysis of its information content; to reveal contradictions in research, design and management processes of ‘Chemical enterprise-environment’ system (ChE-E).

Achievement of electric energy savings through controlling frequency convertor in the operation process of asynchronous motors in textile enterprises

In article are brought frequency regulation of the asynchronous electric motor and that reach to energy saving itself. Frequency management is energy saving so regulation of the frequency of the rotation of the asynchronous engine are provided increasing coefficient of efficiency and reduction of the loss to powers. A machine asynchronous is often used today as a power scale ranging with a motor from some Watts to several thousand kW. For power applications exceeding several kW, asynchronous motors run solely on three-phase AC power supplies. Owing to the sensitivity of a process or the critical nature of certain applications, the network may be supported with an Uninterruptible Power Supply.

Developing a Building-by-Building Estimate of City-wide Electricity Savings Potential: An Early Trial for the City of Wilmington, Delaware

The research outputs of the 2020-2021 “Wilmington as a Savings City” project, conducted jointly by the Center for Energy and Environmental Policy (CEEP) and the Foundation for Renewable Energy and Environment (FREE), provide a methodological framework that can be directly relevant to the City of Wilmington and other cities in Delaware. Using high-resolution and comprehensive data, the research effort pursues a detailed inventory of the Wilmington building stock with which we estimate building-level electricity consumption and possible energy-saving opportunities. As the title of this report indicates, we apply an early trial of the methodological framework that we have developed for the purposes of describing how a new analysis might better serve the purpose of estimating ‘savings city’ potential. We call it an ‘early trial’ to underscore that the model described and applied in this report is part of an ongoing development process. The methodological framework will be refined in order to have practical value to urban planning. The results illustrated in this report should, therefore, be seen as an assessment of the overall value of the methodological framework brings to the table and not firm estimates to be used in planning. Currently, methods to estimate building energy savings potential for a city relies on technology potential for ‘typical buildings’. As discussed below, our team is investigating a method that uses all buildings in a city and is sensitive to the range of differences in building stocks from one city to the next. The promise of this approach is that it can offer estimates derived from actual city building inventories, not ‘typical’ building stocks. The accuracy of estimates produced by this method should be greater and more useful to cities. We recommend its use by the reader to gain familiarity with the tool and its potential.

Decision Support System for Solar Energy Adoption

A decision support system (DSS) is a computerized information system that combines models and data to solve unstructured or semi-structured problems, with intense user involvement. DSSs have high applicability in several business areas and enable users without technical knowledge in computing to manipulate the information needed for a more assertive decision-making process. This study presents a DSS to support the decision process of installing a photovoltaic solution that considers the contracted power, the monthly expenses in electricity, and the location of the installation. The return on investment is estimated considering the annual savings in electricity and the return on investment. The findings indicate the relevance of the application to support the user in choosing the best solution and reveal that geographical location is a determining factor in the potential energy savings. Furthermore, the payback period decreases by increasing users' monthly consumption and is also potentiated by the increase in contracted power.

Examination of vertical green systems in educational buildings: a field study in Çukurova University

The concept of sustainability, which is currently sitting on our agenda with increasing environmental pollution has gradually increased its importance. In order to leave a livable ecosystem for new generations, it is essential that individuals are given the necessary education within the scope of the issues that need to be done. The best training is hands-on training. A person can internalize the concept that he sees, touches, feels in the environment in which he is located, that is, lives with all his perceptions. In this case, building educational structures with the goals of sustainable architecture is an important step in terms of instilling the concept of sustainability in the younger generations. In the context of sustainable design, vertical green systems have taken an important place with the technological developments in recent years and it has been shown that they contribute to achieving sustainable design goals. It is believed that the application of these systems in school structures will make it easier for students to explain the concept of herd, because they are experiential. For these reasons, the aim of the study is to reveal the benefits of vertical green systems in terms of sustainability in educational structures and to present a study that can provide resources for sustainable school designs.In the study, the benefits of vertical green systems were discussed in the context of reducing the urban heat effect, improving air quality, absorbing noise and saving energy. Energy analysis was carried out through revit program by applying vertical green system to the educational buildings selected from Adana Çukurova University in order to demonstrate the benefits of vertical green systems within the scope of energy conservation with data. As a result of the evaluations made, the electrical energy savings of green vertical systems were revealed with numerical data and the criteria to be considered for an environmentally beneficial vertical green system application were explained.

The Factors Affecting Household Electricity Saving Behavior: A Study in Vietnam

In the context of dramatically increase in electricity demand, Vietnam's potential for power supply remains limited. Research and promotion of electricity saving behavior of households become significant to reduce electricity consumption and protect ecological environment. This study incorporates elements of planned behavior theory (TPB) and norm activation model (NAM) as the basis for developing and extending key assumptions. In addition, expansion TPB is used to study influence factors affecting electricity saving behavior. Through a sample of 395 randomly selected residents in Tay Ninh Province and Ho Chi Minh city in Vietnam, the proposals were checked using a structural equation model (SEM). The results showed that the factors in TPB and NAM (such as perceived behavioral control, subjective norm, attitude, personal moral norm) and additional factor (perceived benefit) are the important factors that influence resident's intention of saving electricity. Moreover, electricity saving behavior is strongly influenced by the intention of saving electricity, perceived benefit, policy and social propaganda. Based on these results, some inferences are drawn, and recommendations are made for policy makers and further research proposals are discussed.

An innovative shading controller for blinds in an open-plan office using machine learning

Achieving visual and seasonal thermal comfort is an intractable issue for automated shading controllers over multiple blinds serving large side-lit, open-plan offices, especially when the occupied positions are spatially and temporally transient. In the current literature, few proposals have accounted for this. This study describes a novel model-based shading controller to fulfill this gap by optimizing the vertical eye illuminance conditionally at any occupied place. The controller was generated through real-time daylight simulations and two surrogate model techniques (online and offline) based on the radial basis function neural network. The offline surrogate model can predict timely vertical illuminance at any occupied position in the worst scenarios, and the online surrogate model yields the best combined shading results in a timely manner by an accelerated optimization procedure. The accuracy of the customized prediction models embedded in the controller was verified. Comparative simulations were performed for an open-plan office in Harbin, China. The performance regarding visual comfort, daylighting, electrical energy savings, and seasonal solar heat gains were explored and evaluated, demonstrating the advantages of our proposed control approach.

Impacts of regional industrial electricity savings on the development of future coal capacity per electricity grid and related air pollution emissions – A case study for China

Moving to a sustainable industry and weaning electricity supply off coal are critical to mitigate ambient air pollution and climate change. This is particularly true in China which is globally the largest manufacturer and relies heavily on coal-fired electricity. Research that explores the linkages between industrial electricity use and the electricity supply sector to curb air pollution is limited. In this study, an integrated modeling framework is developed that quantifies the impact of industrial electricity savings on the evolution of the coal power plant fleet in China, and on air pollutants for the different power grids in the period 2016–2040. The framework includes a rich set of efficiency technologies and detailed unit-level information (geo-coordinates, thermal efficiency, environmental performance). We find that the reduced electricity load due to the industrial efficiency improvements can effectively scale down the coal power fleet, and most importantly allows closing the most polluting units. The potentials for electricity savings vary amongst the industrial sectors and provinces, resulting in significant heterogeneity of coal plant phaseout per power grid. Because energy-intensive industrial plants are mostly found in the North, Central and Northwest grids, these three grids provide 66% of the total displaced coal capacity. The closing of coal units leads to a variation in annual emission reductions per power grid of 13–85 kt-SO2, 19–129 kt-NOx, 3–17 kt-PM and 21–167 Mt-CO2, compared to business-as-usual emissions. The iron & steel, aluminium and chemical sectors, together contribute to 84% of the total electricity savings by 2040, and are thereby most important to target.

Cyber-physical production system approach for energy and resource efficient planning and operation of plating process chains

Plating process chains are characterized by a high specific energy and resource demand as well as a high complexity due to dynamic interdependencies between and within processing steps. Planning and operating plating process chains should focus on aspects from cleaner production such as a high energy and resource efficiency, low impacts on the environment as well as on economic aspects. A high process transparency is required to meet these objectives and to evaluate the effects of improvement measures. An energy and resource flow simulation can support this by providing a fully parameterizable digital twin of the physical plating line. This simulation is integrated into a cyber-physical production system approach and connected to the IT environment of the plating company for the simulation of real scenarios. For the parameterization of the energy model, continuous and temporal measurements are combined systematically while the resource flow model is parameterized through information from the manufacturing IT systems. The successful implementation at a job plating company with an industrial acid zinc-nickel plating line indicated reachable electricity and resource savings of up to 10% in four scenarios. The electricity and plating metal demand was allocated to single carriers and products as basis for a product-based environmental and economic analysis. Especially in case of different carrier load levels, the energy and resource demand per product varies significant. The developed approach and its successful implementation emphasizes the need of a high process transparency for planning and operating plating process chains to accelerate the shift towards cleaner production.

Social Versus Private Benefits of Energy Efficiency Under Time-of-Use and Increasing Block Pricing

Many energy policies are implemented to subsidize the adoption of energy efficiency. However, when private benefits from energy efficiency exceed the social benefits, there is an incentive for the consumers to over-invest in energy efficiency; otherwise, there is an incentive to under-invest. This study adds to this discussion by providing an empirical estimation of the electricity savings and social benefits after energy efficiency retrofits for consumers on time-of-use (TOU) and increasing block pricing, respectively. We aim to examine how social versus private savings from a given energy efficiency measure may be different depending on different pricing plans. This study applies hourly electricity data for about 16,000 residential consumers during 2013–2017 in Arizona. We show that for the TOU consumers, the private savings from energy-efficient AC retrofits are greater than the social savings by 61%, while the increasing block rate consumers’ private savings exceed the social savings by 46%, when other market failures are not considered (e.g., principal-agent problem and imperfect information). Different rate plans impose different marginal electricity prices which influence the incentives to invest in energy efficiency as well as electricity consumption behaviors that can influence both the private and social savings from energy efficiency. The result indicates that there should be potentially different levels of policy interventions towards energy efficiency for consumers on different pricing. Additionally, we also find that energy efficiency makes the electricity demand more elastic to price changes.

Energy Saving of a University Building Using a Motion Detection Sensor and Room Management System

To save electricity consumption in university buildings, we measured and compared the amount of electricity use with and without motion detection sensors and room management systems in underground parking lots, lecture rooms, and dormitories of a university building. The underground parking lots and lecture rooms were measured as sensors were applied and then removed during the semester. University classes are held weekly, so it can be assumed that the number of cars and people’s entering and using conditions are the same. In the university’s underground parking lots, a daily electricity savings of 39.5 Wh/(m2 day) of lights was achieved, with a savings rate of 77.6%. In the lecture rooms, these values were 25.0 Wh/(m2 day) and 32.4%, respectively. Savings in the use of air conditioning were 55.0 Wh/(m2 day), with a savings rate of 27.9%. Dormitories use electrical energy for lighting, heating, and socket outlets. As a reference group, 120 rooms were selected and the room management system was applied to 10 samples. For dormitories, daily electricity savings of 142.4 Wh/(m2 day) were achieved, with a savings rate of 28.2%. Thus, this study demonstrated that applying motion detection sensors and room management systems saved significant electrical energy in university underground parking lots, lecture rooms, and dormitories.

Integration of a side-stream microalgae process into a municipal wastewater treatment plant: A life cycle analysis

This study investigates the environmental improvements associated to the integration of a microalgae unit as a side-stream process within an existing municipal wastewater treatment facility in northern Italy. Microalgae are fed on the centrate from sludge dewatering, rich in nutrients, and on the CO2 in the flue-gas of the combined heat and power unit. The produced biomass is recirculated upflow the water line where it settles and undergoes anaerobic digestion generating extra biogas. A life cycle assessment was performed collecting primary data from an algal pilot-scale plant installed at the facility. Fifteen environmental indicators were evaluated. Compared to the baseline wastewater treatment, the new algal configuration allows an improvement for 7 out of 15 indicators mainly thanks to the electricity savings in the facility. Some recommendations are provided to improve the performance of the algal system in the scaling up.

Dynamic Energy Modelling as an Alternative Approach for Reducing Performance Gaps in Retrofitted Schools in Denmark

When considering that over 80% of buildings in Denmark were built before the 1980′s, a holistic energy retrofitting of the existing building stock is a major milestone to attain the energy and environmental targets of the country. In this work, a case study of three public schools is considered for post-retrofit process evaluation. The three schools were heavily retrofitted by September 2018 with energy conservation and improvement measures that were implemented targeting both the building envelope and various energy systems. A technical evaluation of the energy retrofit process in the schools was carried out, when considering one year of operation after the completion of the retrofitting work. Actual data from the heating and electricity meters in the schools were collected and compared with the pre-retrofit design numbers which rely majorly on static tabulated numbers for savings evaluation. It was shown that the retrofit design numbers largely overestimate the attained savings, where the average performance gap between the expected and real numbers for the three schools is around 61% and 136% for annual heating and electricity savings, respectively. On the other hand, an alternative approach was proposed where calibrated dynamic energy performance models, which were developed for the three schools in EnergyPlus, were used to simulate the impact of implementing the retrofit measures. It was shown that implementing this approach could predict much better the impacts of the retrofit process with an average gap of around 17% for heating savings and 21% for electricity savings. Based on the post-retrofit process evaluation in the three schools, it was concluded that using dynamic model simulations has the potential of lowering the performance gap between the promised and real savings when compared to static tabulated approaches, although the savings are still generally over-estimated in both approaches.

Challenges of combining different methods and tools to improve the performance monitoring in buildings: A case study of elementary schools and kindergartens

The European Union has identified buildings as the most promising targets for improving energy efficiency and has quantified a significant energy saving potential associated with the refurbishment of a building’s envelope and the installation of new technologies. The key objective of monitoring and modelling energy profiles in buildings is to provide the necessary background on energy consumption and to allow informed decisions to be made. The modelling usually starts with the integration of energy into the activity flow charts, which is the basis for the decisions on setting up the structure of energy cost centres.This paper evaluates the capabilities of data envelopment analysis in combination with energy cost centre based modelling for the electricity consumption analysis of a selected group of elementary schools and kindergartens. The electricity consumption data was obtained in cooperation with a local energy agency, which was acting as the energy manager for the selected group of buildings. The results confirmed the potential of combining the data envelopment analysis and the energy cost centre based modelling in order to properly identify the schools having the potential for energy efficiency improvements. Additionally, the combination of results obtained with the data envelopment analysis and the contextual parameters hidden in the structure of energy cost centres provides additional and valuable information for the energy manager and helps him with proper benchmarking of the analysed energy management practices. The results encouraged the energy manager to look for concrete opportunities to improve the energy efficiency and revealed that electricity savings of up to 14% could be achieved with better energy management in the selected group of buildings.

Internet of things and cloud computing‐based energy management system for demand side management in smart grid

A smart grid is an electricity network, which deals with electronic power conditioning and control of production, transmission, and distribution of electrical power by employing digital communication technologies to monitor and manage local changes in electricity usage. In the traditional power grid, energy consumers remain oblivious to their power consumption patterns, resulting in wasted energy as well as money. This issue is severely pronounced in the developing countries where there is a huge gap between demand and supply, resulting in frequent power outages and load-shedding. For electrical energy savings, the smart grid employs demand side management (DSM), which refers to adaptation in consumer's demand for energy through various approaches such as financial incentives and awareness. The DSM in future smart grid must exploit automated energy management systems (EMS) built upon the state-of-the-art technologies such as the internet of things (IoT) and cloud and/or fog computing. In this paper, we present the architecture framework, design, and implementation of an IoT and cloud computing-based EMS, which generates load profile of consumer to be accessed remotely by utility company or by the consumer. The consumers' load profiles enable utility companies to regulate and disseminate their incentives and incite the consumers to adapt their energy consumption. Our designed EMS is implemented on a Project Circuit Board (PCB) to be easily installed at the consumer premises where it performs the following tasks: (a) monitors energy consumption of electrical appliances by means of our designed current and voltage sensors, (b) uploads sensed data to Google Firebase cloud over many-to-many IoT communication protocol Message Queuing Telemetry Transport (MQTT) where consumer's load profile is generated, which can be accessed via a web portal. These load profiles serve as input for implementing the various DSM approaches. Our results demonstrate generated load profiles of consumer load in terms of current, voltage, energy, and power accessible via a web portal.

Transitions towards energy-efficient appliances in urban households of Gujarat state, India

ABSTRACT Residential sector accounted for 24% of the total electricity consumption in India during 2009–10 and has almost remained around one-quarter over the last decade. A total of 163 same urban households were surveyed in 2018 to ascertain the change in penetration and use of energy-efficient (EE) appliances therein over 2010–18. There was a significant increase in their penetration across each enduse category with main changes being in air conditioners (ACs) (47%) and LED lights (over 38 times) over 2010–18. The weighted average relative electricity consumption decreased from 0.89 to 0.44 for ACs (1.5TR), 0.42 to 0.23 for lighting lamps, 0.95 to 0.54 for tubelights, 0.98 to 0.68 for refrigerators, and 0.94 to 0.69 for TVs, indicating the lowering of average energy consumption due to EE appliances. The annual electricity savings at household level were found statistically significant for transitions to EE ACs and ceiling fans.

Elimination of the juice clarifier and the drum vacuum filter at a cane sugar plant

The sugar manufacturing process includes many stations with specific residence times for proper and complete reactions. Sugar losses due to inversion in sugar processing are mainly influenced by temperature, pH value, d.s. content, and residence time of the juices/syrups. Reducing the residence time by the elimination of some process steps would reduce sucrose loss. Recycling of clarifier underflow into the cane diffuser was initiated in 2004. At the sugar units of The Andhra Sugars Limited the drum vacuum filter is no longer used. In the 2012/13 milling season at plant-3 a plant-scale run of clarification of juice in the diffuser to produce diffuser clear juice (DCJ) was carried out. The juice clarifier was bypassed with encouraging process and financial outcomes. With the elimination of the drum vacuum filter and the juice clarifier, there was a gain in sugar recovery as well as savings in manpower, electricity, steam, and maintenance costs. For a new raw sugar plant using this process the capital costs would be reduced.

Electricity savings and greenhouse gas emission reductions from global phase-down of hydrofluorocarbons

Abstract. Hydrofluorocarbons (HFCs) are widely used as cooling agents in refrigeration and air conditioning, as solvents in industrial processes, as fire-extinguishing agents, for foam blowing, and as aerosol propellants. They have been used in large quantities as the primary substitutes for ozone-depleting substances regulated under the Montreal Protocol. However, many HFCs are potent greenhouse gases (GHGs) and as such subject to global phase-down under the Kigali Amendment (KA) to the Montreal Protocol. In this study, we develop a range of long-term scenarios for HFC emissions under varying degrees of stringency in climate policy and assess co-benefits in the form of electricity savings and associated reductions in GHG and air pollutant emissions. Due to technical opportunities to improve energy efficiency in cooling technologies, there exist potentials for significant electricity savings under a well-managed phase-down of HFCs. Our results reveal that the opportunity to simultaneously improve energy efficiency in stationary cooling technologies could bring additional climate benefits of about the same magnitude as that attributed to the HFCs phase-down. If technical energy efficiency improvements are fully implemented, the resulting electricity savings could exceed 20 % of future global electricity consumption, while the corresponding figure for economic energy efficiency improvements would be about 15 %. The combined effect of HFC phase-down, energy efficiency improvement of the stationary cooling technologies, and future changes in the electricity generation fuel mix would prevent between 411 and 631 Pg CO2 equivalent of GHG emissions between 2018 and 2100, thereby making a significant contribution towards keeping the global temperature rise below 2 ∘C. Reduced electricity consumption also means lower air pollution emissions in the power sector, estimated at about 5 %–10 % for sulfur dioxide (SO2), 8 %–16 % for nitrogen oxides (NOx), and 4 %–9 % for fine particulate matter (PM2.5) emissions compared with a pre-Kigali baseline.

Influence of Energy-Saving Systems Using Natural Cold on the Energy Intensity of the Milk Cooling Process

Reduction of energy consumption in technological processes of cooling and storage milk on farms is urgent task.(Research purpose) The research purpose is in reducing the energy intensity of the milk cooling process on farms while maintaining its quality.(Materials and methods) The authors conducted research to improve existing and create new smart combined cooling systems based on the rational use of natural and artificial cold sources with means of its accumulation and environmentally friendly coolants with low freezing point.(Results and discussion) The authors have found the dependence of the amount of energy that can be used for cooling and storage of milk and dispersed into the environment on the potential of natural cold of the area and the location of the technological object. The article presents a methodology for assessing the potential of natural cold for different regions of Russia. According to the methodology, authors calculated the values of the ice storage capacities for dairy farms with different livestock and annual milk yield. The article presents the diagram of electric energy savings when using natural cold to cooling milk on farms of 400 heads with a yield of 5000 liters in different climatic regions of Russia. Significant energy savings can be obtained through the use of combined accumulators of natural and artificial cold using environmentally friendly coolants with low freezing point and ground ice storage, in which the freezing of soil and water is carried out due to the ground cooling thermal installation with twophase thermosyphons.(Conclusions) The use of smart combined milk cooling systems on farms on the basis of sources of natural and artificial cold with means of its accumulation and environmentally friendly coolants with low freezing point allows to reduce energy consumption in 1.5-3 times at preservation of its quality. At the same time, such systems in various configurations can be effectively used in all agroclimatic regions of the country.

Co-benefits of Energy-Efficient Air Conditioners in the Residential Building Sector of China.

Electricity demand for room air conditioners (ACs) has been growing significantly in China in response to rapid economic development and mounting impacts of climate change. In this study, we use the bottom-up model approach to predict the penetration rate of room ACs in the residential building sector of China at the provincial level, with the consideration of the urban-rural heterogeneity. In addition, we assess co-benefits associated with enhanced energy efficiency improvement of AC systems and the adoption of low-global-warming-potential (low-GWP) refrigerants in AC systems. The results indicate that the stock of room ACs in China grows from 568 million units in 2015 to 997 million units in 2030 and 1.1 billion units in 2050. The annual electricity saving from switching to more efficient ACs using low-GWP refrigerants is estimated at almost 1000 TWh in 2050 when taking account of the full technical energy efficiency potential. This is equivalent to approximately 4% of the expected total energy consumption in the Chinese building sector in 2050 or the avoidance of 284 new coal-fired power plants of 500 MW each. The cumulative CO2eq mitigation associated with both the electricity savings and the substitution of high-GWP refrigerants makes up 2.6% of total business-as-usual CO2eq emissions in China over the period 2020 to 2050. The transition toward the uptake of low-GWP refrigerants is as vital as the energy efficiency improvement of new room ACs, which can help and accelerate the ultimate goal of building a low-carbon society in China.