Electricity Savings Research Articles

Low Carbon Transition of Residential Electricity Consumption in Nigeria: A System Dynamics Modeling Approach

It is imperative that Nigeria reduces wastage in residential electricity consumption and motivate energy saving behaviors through energy efficiency measures. These strategies aim to minimize frequent power sheds, which in turn increase reliability, thus benefiting the environment and electricity consumers. This article examines the effects of such innovative approaches to electricity savings in Nigeria through: 1) prepaid electricity metering systems and 2) fast replacements of inefficient and aging appliances. Relationships between residential electricity consumption, energy efficiency, and carbon footprint were also assessed vis-a-vis the replacement of old energy appliances and analogue electricity billing systems with more efficient devices and through prepaid metering systems, respectively. These techniques intend to promote energy saving behaviors. A System Dynamics model built on Stella platform, is used to analyze the implication of energy efficiency policy implementation on residential electricity consumption based on a simulation period of 41 years (2010 - 2050). Secondary data were sourced from the Bureau of Statistics, published articles, Nigerian power sector, World Bank, and primary data using cross sectional surveys of residential electricity consumers. Results, not only revealed that availability and utilization of prepaid electric meters and efficient appliances would motivate electricity saving behaviors, but also showed that efficient technologies could be the main drivers to future energy savings. Results also showed that carbon emissions were cut down by 45% in 2050. In addition, changes in electricity tariffs did not have any consequential effect on electricity consumption, but would rather influence electricity demand. Also, large number of occupant per house might have a negative impact on the Nigerian economic growth. Finally, results suggest that subsidies should be used on new household appliances as an effective energy policy measures. The developed model can be replicated in similar sectors in other emerging economies.

An Empirical Study of the Acceptance of IoT-Based Smart Meter in Malaysia: The Effect of Electricity-Saving Knowledge and Environmental Awareness

Today's increasing demand for electricity requires solutions that better align with energy demand and supply. Innovative technological solutions such as smart metering applications are gaining popularity among electricity providers. Despite numerous benefits, smart meters, a part of the technology on the Internet of Things (IoT), continue to struggle for widespread consumer acceptance due to limited knowledge on electricity savings and environmental awareness. These factors were examined in isolation and have not been theoretically incorporated or examined. Hence, this study investigates the factors that influence residential consumers' acceptance of smart meters by integrating electricity-saving knowledge and environmental awareness with the second generation of “unified theory of acceptance and use of technology” (UTAUT2). The literature revealed an important link between users' behavioural intention and users' use behaviour. Well-established theories of acceptance like “technology acceptance model” (TAM) and UTAUT, incorporate the behavioural intention variable in the nomological network of technology adoption determinants. This study highlighted the impact of users' behavioural intention on users' use behaviour, which was not examined previously by any of the smart meter acceptance models. The data were collected from 318 consumers of residential smart meters in Putrajaya and Malacca, the cities in Malaysia, and were statistically tested using SME-PLS The study confirms that adding electricity-saving knowledge and environmental awareness to the UTAUT2 leads to a significant increase in the explained variance in consumer acceptance of smart meter.

Income Residential Demand Elasticities for Electricity: Do We Need to Differentiate the Tariff?

This study assesses how the Russian household welfare rate impacts electricity consumption volume. Modeling of Russia Longitudinal Monitoring Survey (RLMS) data provided by the Higher School of Economics (HSE) has revealed a heterogeneous dependency between average per capita family income and electricity consumption volume. Electricity demand is not elastic among both urban and countryside residents. However, urban consumption is better described by a linear function, while rural consumption is better described by a quadratic function. The electricity tariff is not statistically significant for urban residents, whereas the price elasticity of electricity consumption for rural residents is close to 1. Application of lifeline rates for electricity tariffs in certain regions did not affect the level of elasticity of consumption by income, but some anomalies have been identified that indicate forced savings of electricity in order to pay for it at a minimum price. The study provides a divided quantitative assessment of influence of some non-income determinants on electricity demand among urban and countryside residents: number and age of family members, residential property area etc. The conclusion deems increasing block tariffs unreasonable because higher electricity tariffs may affect low-income groups thus raising the national poverty rate. If the cross subsidization problem in Russia is nevertheless addressed by imposing increasing block tariffs, the number of blocks and, respectively, prices must be more than two, while threshold consumption volumes should be estimated taking into account non-income determinants on different levels for different social groups.

ENERGY WHICH IS CONVERTED BY THE HEAT PUMP AS A MEANS OF REDUCING COSTS FOR HEATING RESIDENTIAL BUILDINGS

The concept of optimizing heating costs for a separate residential building at the expense of supplying the energy transformed by the heat pump to the home and the changes in the heat energy losses everywhere external walls is presented in this work.The main purpose of the article is to determine the rational modes of operation of the heat pump, on the condition that there is compensation for the cost of heat through the walls of the building. This allows to adjust the heating costs of the building through the use of a heat pump, reducing the coefficient of thermal conductivity of the material of the walls of the house and saving electricity. Electricity savings result from reducing the heat pump's operation and reducing heat loss through the walls of a residential building. Calculation of thermal energy losses through the walls was carried out on the basis of calculations of tabular data and research on the operation of the heat pump, which were carried out on the basis of the physical model of the thermal installation. In assessing the economic efficiency of the heat pump it takes into account the difference in size of market rates for equivalent amounts of electricity and heat as the heat pump to work consumes electricity and useful thermal energy is consumed. With the integrated use of the heat pump and a 41.5% reduction in the coefficient of thermal conductivity of the material of the walls of the building, it will allow an additional 43.5% increase in the cost of heating.

Green Cities and Sustainable Urban Development:(Subject review)

Sustainable urban planning provides the path to combat climate change for cities. Integrated urban areas built to put together residents, events, structures, and public facilities, with simple walking and cycling links between them and almost an outstanding transport service to the rest of the world. In other words, a town built with socioeconomic, cultural, environmental (usually referred to as triple) factors is sustainable development, economic growth, or eco-city (also referred to as ecocity. The work presents the assorted key dimensions of green cities and sustainable urban development with diverse perspectives on global scenarios so that detailed analytics can be done. By incorporating environmentally friendly materials and systems, getting better indoor air quality including using rational or high-efficiency street lights, it minimizes the impact of a building on its natural environment; moreover, those who work or live in these buildings benefit directly from these differences. As a result of the improved conditions, some homeowners have even reported increased productivity for workers. These advantages are more difficult to calculate than pure electricity savings, so conventional accounting approaches that do not consider 'external' urban so national expenses and rewards will potentially underestimate the true worth of high-performance buildings.

Appliance Specific Feedback and Social Comparisons: Evidence From a Field Experiment on Electricity Saving

The provision of feedback about individual electricity consumption is a widely used approach to promote pro-environmental behavior. This form of feedback typically invokes social comparisons by informing households about their aggregate electricity consumption relative to others. While previous research has shown that aggregate consumption feedback translates into significant energy savings, the potential for further reductions may remain untapped because households lack knowledge about their appliance energy consumption patterns. In this paper, we present evidence from a field experiment, where we provide residents with feedback about their electricity consumption, specific to a high-energy use appliance (i.e. air-conditioner). We provide the relevant social norm information by varying the reference group of each resident. We find that our appliance-specific feedback is a powerful tool to curb electricity consumption. Residents significantly reduce their average air-conditioning usage by 17\% in our treatment groups. Notwithstanding, our effects are not driven by comparative feedback with respect to different reference groups. We interpret this as encouraging evidence to promote the use of appliance-specific feedback to realize energy savings.

Promoting a circular economy in the solar photovoltaic industry using life cycle symbiosis

As society works to reduce its reliance on fossil fuels, the demand for renewable energy has grown rapidly in recent years. Photovoltaic (PV) solar power is one such source of renewable energy and has seen significant growth over the past several decades. While End of Life (EoL) PV volumes remain relatively small at this time, the number of EoL PVs is estimated to grow dramatically in the near future. This raises concerns about the management of EoL PVs. Effective EoL management methods need to be aggressively developed and implemented in order to prevent large volumes of hazardous wastes from being disposed in landfills. At the same time, PV waste can also be viewed as a potential source of valuable materials. The development of effective processing technologies to isolate these materials will help divert waste away from landfills while reducing dependence on virgin resources and enhancing economic sustainability. This paper proposes the circularization of the PV industry by applying the notion of Life Cycle Symbiosis (LCS), an extension of Industrial Symbiosis (IS). By identifying waste streams that may have value as potential raw material/feedstock, through the development of collaborative business/economic interactions among a diverse set of organizations, we have applied LCS in the context of EoL PVs. The avoided global warming potential (GWP) and ecotoxicity impacts 2750 kg CO2 eq and 32,000 CTUe per metric ton of EoL PVs respectively, while the water savings and electricity savings were 37,735.65 m3 and 3615.11 MJ per metric ton of EoL PVs.

Optimization of the thermal circuit by introduction of the steam screw-rotor machine

The aim of the work is to increase the efficiency of the CHP by introducing a steam screw-rotor machine (SSRM) into the thermal circuit. It is proposed to exclude the passage of steam from the selection of the turbine through the pressure reduction and desuperheating station (PRDS) of own needs. Superheated steam is diverted to be sent to a steam screw-rotor machine installed parallel to the PRDS. This technical solution will allow to obtain steam used in low pressure deaerators, as well as electricity for own needs of the CHP. The article presents the operating parameters, as well as the calculation results of the backpressure turbine. A feasibility study was carried out for the introduction of SSRM into the plant’s thermal circuit: the equivalent fuel and electricity savings for own needs were calculated, as well as the payback period of the project for introducing a steam screw-rotor machine. In the course of the calculations, the following results were obtained: a decrease in the specific consumption of equivalent fuel for the production of 1 kWh of electricity – by 1,9 g; saving of equivalent fuel during the implementation of the SSRM will be 13 tons per year, which also entails a reduction in emissions into the environment; Electricity production for own needs is 8100 kWh, the payback period for the project to introduce a steam screw machine in the thermal circuit of a thermal power plant is 5 years.

Desiccant cooling as an alternative to traditional air conditioners in green cooling technology

Desiccant-based dehumidification and air conditioning systems are considered as an energy efficient alternative to traditional vapor compression based air-conditioning systems for green building cooling technology especially in tropical hot and humid ambient climates. It is a novel green cooling technology that makes use of low-grade heat for building air conditioning. It is seen that the desiccant based dehumidification and cooling can efficiently provide comfort conditions in subtropical and especially hot and humid tropical climates. The desiccant integrated novel cooling system has a significant higher coefficient of performance compared to the conventional vapor compression system resulting to substantial electrical energy savings during the summer season by use of renewable solar energy, which also resulted in to major reduction in CO2 emissions. Therefore, these results demonstrate that there is a good potential in desiccant-based dehumidification and cooling system for energy and carbon savings while carry out building air-conditioning. Through a literature review, the feasibility of the desiccant assisted air conditioning in hot and humid climatic conditions is proven and the advantages it can offer in terms energy and cost savings are underscored. Keywords: Air-conditioning; Desiccant cooling; Dehumidification; Green cooling; Thermal comfort

A Photo‐Assisted Chargeable Aqueous Zinc‐Iodine Battery

AbstractSolar energy is an abundant and renewable energy resource, but it must be captured and stored for practical application in view of the intermittency and low‐energy density. The search for an effective solar energy storage system is highly required, yet remains a challenge. In this paper, we design a novel solar energy storage device by integrating a TiO2 photo‐electrode into an aqueous zinc‐iodine battery (ZIB). During charging process under illumination, I− in catholyte is oxidized to I3− by photo‐excited holes from TiO2 photo‐electrode. Meanwhile, the photo‐excited electrons transfer to the anode through the external circuit and reduce the Zn2+ into Zn. Due to the compensation of photo‐voltage, an ultralow charging voltage of 0.56 V is achieved, much lower than the discharging voltage (1.2 V), resulting in 54 % input electric energy savings.

Optimal carbon-neutral retrofit of residential communities in Barcelona, Spain

This paper investigates the optimal retrofit solutions for residential communities to be carbon neutral in Barcelona, Spain. In particular, three different sizes for the residential communities are considered depending on the number of housing units: small, medium, and large. First, the best cost-effective energy efficiency measures (EEMs) have been determined and applied to all the buildings of the communities, in order to reduce their overall energy demand. The retrofit optimization results demonstrate that combinations of passive and active strategies would achieve source energy use saving and electrical peak demand savings up to 57% and 29%, respectively. Then, a variety of renewable energy generation systems has been explored to determine the optimal grid-connected technologies for meeting the electricity demands while achieving annual carbon neutral conditions for the residential buildings. The analysis shows that wind turbines can reduce the cost of electricity generation up to 21.5% compared to the current utility prices (LCOE value as 0.247 €/kWh) and electricity sell back policies. The results indicate that for PV systems to compete with wind turbines, their capital costs need to be lower by at least 40% compared to the current level costs.

Quantifying potential savings from sustainable energy projects at a large public university: An energy efficiency assessment for texas state university

At Texas State University (TSU) in the United States, “sustainability” is pursued within the context of (1) a non-binding declaration in the University’s plan, and (2) a State legislative directive to reduce energy consumption. Grounded in these direct links between sustainability and energy use, this paper evaluates energy efficiency at TSU. The aim of the applied case study is to inventory current (business as usual) energy consumption levels at TSU, and to understand how those levels might change under a regime of more sustainable energy technology. The paper performs financial analysis to show that selected sustainable energy projects can not only reduce energy use at TSU, and thereby strengthen the University’s commitment to sustainability. Sustainable energy projects will also save the University money in the long run. The case study draws on a sample of the 13 on-campus buildings with the highest current levels of energy consumption. The approach of the paper is to determine the level of attractiveness of investing in new technology by calculating the Net Present Value (NPV) in terms of financial savings every year (simple payback) or a more extended period (cash flow model). The environmental impact is calculated in terms of CO2 emission based on Scope 2 methodology. We find that TSU could achieve annual electricity savings of 15,391,436 kWh (17% of its annual energy costs) from implementing selected projects and save more than $1,000,000 in annual costs. Overall, TSU could reduce CO2 emissions by 12,561.81 metric tons. The shortest payback period belongs to the pump replacement, and the most significant annual kWh saving is represented by the replacement of the lighting system. Solar panel installation has the highest upfront investment reaching more than $7 million, while its implementation will bring the highest environmental impact by avoiding 2926.81 metric tonnes of CO2 every year. However, the recommended minimum cost of energy at 14–16 (¢/kWh) for solar panel implementation cannot compete with the 8 cents per kWh paid for the electricity at San Marcos. The findings have immediate practical relevance for campus planning at TSU, and the methods are replicable and extendable for use by practitioners and researchers at other Universities or large institutions.

Pilot-Scale Assessment of a Novel Farrowing Creep Area Supplementary Heat Source.

Simple SummaryPre-weaning mortality (PWM) causes major economic and productivity losses for the US swine industry. This pilot-scale study evaluated a novel semi-enclosed heated microclimate (SEHM) as a supplementary heat source for farrowing creep areas. Six farrowing cycles (from January to July 2019) were studied in two rooms with 24 farrowing stalls per room. Six SEHMs (each SEHM covers two stalls) were randomly distributed in each room and compared to heat lamps (HLs) for productivity and electricity usage. Data were collected on 113 (SEHM) and 101 litters (HL), and there was no statistically significant difference for average daily gain and weaning weight. There was a tendency for significance of PWM (p = 0.08). A significant difference (p = 0.02) was noted in the PWM attributed to over-lay mortalities, SEHM = 4.05% (± 0.76%) compared to HL = 6.04% (± 0.78%). The SEHM averaged 3.25 kWh d−1 (2.91, 3.59 kWh d−1; 95% CI), which was significantly different (p < 0.01) from the HL equivalent with 125 W bulbs (6 kWh d−1). Based on only electrical savings, payback was estimated at 74 farrowing cycles, or at 12 cycles y−1, 6.1 years. The SEHM demonstrated promising pilot-scale results for increasing productivity and decreasing electricity usage compared to conventional HLs.Pre-weaning morality (PWM) is attributed to a poor creep area microclimate and causes major economic and productivity losses for the US swine industry. Piglets need supplementary heat to overcome a high surface area to body weight ratio and minimal thermoregulation. A pilot-scale study was conducted to evaluate a semi-enclosed heated microclimate (SEHM) as a supplementary heat source for farrowing creep areas over six farrowing cycles (from January to July 2019) in two rooms with 24 farrowing stalls in each room. Six SEHMs (each SEHM covers two stalls) were randomly distributed to each room and compared to heat lamps (HLs) for productivity and electricity usage. Data from 113 (SEHM) and 101 litters (HL) showed no significant difference between treatments in average daily gain (p = 0.26), 252.4 ± 8.0 g hd−1 d−1 (SEHM) and 260.3 ± 8.1 g hd−1 d−1 (HL) and PWM (p = 0.08), 9.67% ± 0.82% (SEHM) and 12.04% ± 0.87% (HL). However, a significant difference (p = 0.02) was noted in the PWM attributed to over-lay mortalities, 4.05% ± 0.76% (SEHM) compared to 6.04% ± 0.78% (HL). The SEHM electricity averaged 3.25 kWh d−1 (2.91, 3.59 kWh d−1; 95% CI), which was significantly different (p < 0.01) from the HL equivalent (125 W bulb; 6 kWh d−1).

Efficiency analysis on the inverter using the energy-saving lamp

Electric energy savings are influenced by magnitude of reactive power used by electric customers, one of the tools that can minimize reactive power is the inverter, which is an electronic equipment, that can change the direct current of electricity to alternating current, The method used is by measuring along with analysis of calculation each time the inverter is given the burden of energy-saving lamps with varying power to determine the change in the electrical quantities to be analyzed. Inverter efficiency in doing the convert direct current to alternating current during low load (5W) amounted to 94.66%, and the highest load current (203W) amounted to 90.55%.

Use of a turbine expander to generate electricity for own operation needs of a gas turbine unit at compressor stations of main gas pipelines

In order to save energy at compressor stations, it is proposed to use expander-generating units (EGU) to reduce gas pressure. An analytical justification for replacing a throttle by EGU is given. The results of economic calculation of electricity savings when using EGU are given. The scheme of gas turbine unit with EGU and gas heating before entering the combustion chamber is presented. When using this scheme, the cost savings for electricity purchase is 83%.

Pilot study of ‘Our Energy’, an app designed to facilitate self-consumption of community solar photovoltaic systems

Distributed energy from photovoltaic (PV) systems are an important part of the 2000-Watt-Society and Swiss Energy Strategy 2050 targets. However, as more PV is added to the grid, it becomes more important to intelligently use on-site electricity generation. There is also a recent focus on communities as they have better load aggregation potential from multiple tenants to increase overall self-consumption. Additional potentials exists when introducing PV systems in communities from social comparisons or competitions. The first critical step is to have an effective communication platform with real-time electricity production and consumption to show resource availability and usage at the individual and community level. We have therefore developed ‘Our Energy’, a custom mobile application (app) to ‘experience’ what it would be like to have direct access to electricity from solar PV in a community setting. It is designed to facilitate demand side response for users to compare their household energy consumption and associated self-consumption from. This study uses a community based social marketing approach to support the app design, development, evaluation and deployment for a specific user group from a small Swiss city. This paper includes the results from a pilot study where the beta version of the app was tested during two weeks in March 2019 with 32 participants. The feedback helped improve the demand side response strategy along with the real-time statistics for participants to monitor self-consumption and electricity savings potential from Solar PV.

DESIGN AND DEVELOP AUTOMATION SYSTEM FOR SAVING ELECTRICAL ENERGY IN THE STTAL OFFICE ROOM

The use of electricity in offices has been considered too wasteful. This is caused by human negligence in controlling their use. For this reason, this research was carried out as an effort to find the right method to reduce the high electricity consumption in offices. This research was conducted in the STTAL classroom, Bumimoro, Surabaya. From the results of the calculation, the total heat load in the classroom is 32,048.3 BTU or ± 4 PK. Total installed AC capacity is only 2 PK. This automation tool is a system that works automatically to regulate the use of electrical equipment based on parameters that have been determined in a program such as the presence or absence of humans, the level of light intensity and room temperature. Data collection is carried out for 6 days in the classroom, 3 days without tools and 3 days using the automation tool. Furthermore, the data is compared to the graph and the savings are calculated. The result, on day 1 is 56.11%, days 2 and 3 are 10.26% and the average savings for the 6-day trial is 33.43%. All data is recorded automatically on a micro sdcard and information about the amount of electricity consumption and the ON / OFF feature of electrical equipment can also be accessed via a smartphone with a wifi network so that users will find it easier to monitor the use of electrical equipment in the classroom.Keywords: electricity waste, heat load, automation system, electricity monitoring, electricity savings.

The Potential Energy Efficiency Improvements for the Italian Pulp and Paper Industry

Pulp and paper production is an energy intensive process, that accounts for about 9 % of industrial final energy use in Italy in 2016. While the energy intensity of the total manufacturing sector has decreased by 51 % over the last twenty years, pulp and paper industry has shown a slower improvement, of only 4 %. The sector presents wide opportunities for improving energy efficiency and, for this purpose, adequate knowledge of the energy saving potentials and their costs are essential prerequisites to design effective policies. In this paper, after assessing the current technologies and energy performance of the Italian pulp and paper industry, we identify the technical and economic potentials for fuel and electricity savings in the sector. While many studies in this field use data on efficient technologies from available literature, surveys or even theoretical estimates, the added value of this paper is the use of real data coming from 110 energy efficiency measures implemented in the field by the pulp and paper companies under the Italian White Certificates Scheme.The analysis indicates that the energy saving potentials, under conservative technology penetration rates, amount to 0.88 TWh for electricity and 4.47 TWh for fossil fuels consumption: such savings equal 12.6 % and 18.6 % of the sector electricity and fuel demand, and can be translated into mitigated CO2 emissions of 353 kt.

Experimental study of model predictive control for an air-conditioning system with dedicated outdoor air system

Using separate cooling coils for sensible and latent loads provide extra control flexibility to optimise the energy efficiency and comfort in air-conditioning and mechanical ventilation (ACMV) systems. A popular implementation of such technology is dedicated outdoor air system (DOAS)-assisted separate sensible and latent cooling (SSLC) systems. However, a sophisticated control technique is needed to coordinate the control of multiple cooling coils in such systems. This paper presents a novel model predictive control (MPC) developed for a DOAS-assisted SSLC system. The MPC adopts a linear state-space model that captures building thermodynamics, thermal comfort and ACMV for building response prediction and optimization. Subsequently, a multi-objective cost function is employed to optimize energy use and thermal comfort while fulfilling constraints of predicted mean vote (PMV) (-0.5, 0.5) and relative humidity (0%, 65%) in buildings. The performance of the MPC for controlling a conventional single-coil air-handling unit (AHU) system and a DOAS-assisted SSLC system is experimentally investigated and compared to a conventional feedback-control-based building management system (BMS). The MPC system achieved 18% and 20% electricity savings for the single-coil AHU and DOAS-assisted SSLC, respectively, as compared to the BMS controlled single-coil AHU. Furthermore, indoor thermal comfort is significantly improved, compared to the BMS. DOAS-assisted SSLC is shown to be advantageous compared to single-coil AHU to achieve better indoor environment in terms of thermal comfort and humidity, when both systems are controlled by MPC.

Determining Factor/s of Window Glazing Regarding Reduction in Electrical Energy Consumption

Abstract Among all building envelops, windows are typically the weakest barrier to heat ingress. The building energy consumption of any conditioned building located in the tropical country is deeply governed by the amount of heat gain inside the building because heating ventilation and air-conditioning (HVAC) system is a major energy consumer. Hence, it can be easily inferred that the energy consumption of a building can be reduced through judicial selection of window glasses. This paper illustrated the importance of thermal transmittance (U-value) and solar heat gain coefficient (SHGC) value of window glazing in detail and also demonstrated the energy savings potential of various types of commercially available windowpanes. The electric energy savings potential of various types of windowpanes such as tinted, reflective, single glazing, and double glazing glasses have been analyzed through eQUEST energy simulation software for a building, situated in the tropical region of India. Building architectural data and all other information regarding HVAC, lighting, etc. have been collected during the energy audit and trained in the eQUEST simulation for further analysis. The calibration of simulation model has been done using actual monthly electricity consumption data of the case building. This study depicts the percentage decrease in electrical energy consumption due to retrofitting of various commercially available window glasses compared with base building. The study also compares the importance of main two determining factor(s) U and SHGC value behind the judicial selection of proper window glazing.