Residential Applications Research Articles

Thermal study on novel spokes fin for high power LED

High Power LED (HPLED) lights are popular today in industrial, residential, and consumer applications. In this work, under natural cooling considerations, on a commercial (size 17.85 × 17.85 × 3 mm) heatsink base, a novel spokes fin model was introduced and the temperature has been investigated and compared with rectangular and circular fin models. Using commercial FEA tool, the effect of heat transfer has been explored for a single and six HPLED arrays integrated on the top of the heat sink base and for different fin lengths, about 60 mm, 70 mm and 80 mm and junction temperatures 130 °C, 110 °C, 90 °C, 70 °C and 50 °C. The results revealed that the novel spokes fin is effective at about 4.72% (6 °C) on the upper part of the fins and 5.87% (13 °C) on the lower part of the fins. The heat dissipation from the HPLED junction to the atmosphere is effective using novel spokes compared to rectangular fins for both single and six HPLED array configurations. At the same time, the rectangular fin is effective in dissipating the heat for a single HPLED operation compared to the circular fin about 2.85% on the upper fins, 3.66% on the lower fins and has an equal dissipation effect while used for six HPLED array configurations. During the simulation, the mesh independence test is conducted and the radiation effect is also considered.

Optimal scheduling of prosumer's battery storage and flexible loads for distribution network support

AbstractHere, an efficient Energy Management System (EMS) for residential installations is proposed. The EMS handles on site Photovoltaic (PV) power production along with Battery Energy Storage System (BESS) and performs load shifting under a Demand Side Management (DSM) scheme that considers user comfort. The goal of the proposed methodology is the minimization of power exchange between the prosumer and the grid. In this way, the power flow across the Distribution Network (DN) is decreased, thus reducing power losses, and improving the voltage profile along the DN. Moreover, the EMS increases the self‐sufficiency of the residence. The minimization problem is solved via a metaheuristic algorithm, namely Unified Particle Swarm Optimization (UPSO) utilizing real consumption patterns for residential appliances. The latter adds complexity to the problem but offers accurate modelling of the power demand and improves the performance of the EMS scheme. The proposed EMS is locally implemented as a plug‐and‐play scheme and benefits both the prosumer and the DN under low computational burden, proving to be efficient. Simulation results for a case study verify the efficiency of the proposed EMS and the comparison with other similar methods proves its superior performance.

Environmental Impact Assessment of PEM Fuel Cell Combined Heat and Power Generation System for Residential Application Considering Cathode Catalyst Layer Degradation

Recently, fuel cell combined heat and power systems (FC-CGSs) for residential applications have received increasing attention. The International Electrotechnical Commission has issued a technical specification (TS 62282-9-101) for environmental impact assessment procedures of FC-CGSs based on the life cycle assessment, which considers global warming during the utilization stage and abiotic depletion during the manufacturing stage. In proton exchange membrane fuel cells (PEMFCs), platinum (Pt) used in the catalyst layer is a major contributor to abiotic depletion, and Pt loading affects power generation performance. In the present study, based on TS 62282-9-101, we evaluated the environmental impact of a 700 W scale PEMFC-CGS considering cathode catalyst degradation. Through Pt dissolution and Ostwald ripening modeling, the electrochemical surface area transition of the Pt catalyst was calculated. As a result of the 10-year evaluation, the daily power generation of the PEMFC-CGS decreased by 11% to 26%, and the annual global warming value increased by 5% due to the increased use of grid electricity. In addition, when Pt loading was varied between 0.2 mg/cm2 and 0.4 mg/cm2, the 10-year global warming values were reduced by 6.5% to 7.8% compared to the case without a FC-CGS.

Solubility, Diffusivity, and Permeability of HFC-32 and HFC-125 in Amorphous Copolymers of Perfluoro(butenyl vinyl ether) and Perfluoro(2,2-dimethyl-1,3-dioxole)

R-410A, an azeotropic mixture composed of 50 wt % difluoromethane (HFC-32, CH2F2) and 50 wt % pentafluoroethane (HFC-125, CHF2CF3) used in residential and commercial air-conditioning applications, will be phased down due to the high global warming potential (GWP) of HFC-125. The HFC-32 can be reused in low-GWP blends containing hydrofluoroolefins (HFOs); however, incumbent separation technology, fractional distillation, cannot separate azeotropic mixtures. Membrane technology provides the opportunity to achieve a selective separation of azeotropic HFC refrigerant mixtures with lower energy consumption and capital requirements. This study explores the use of amorphous perfluoropolymers for the separation of R-410A. The permeability, solubility, and diffusivity of HFC-32 and HFC-125 were measured in copolymers of perfluoro(butenyl vinyl ether) (PBVE) and perfluoro(2,2-dimethyl-1,3-dioxole) (PDD). Pure gas permeability of HFC-32 and HFC-125 were measured using a static membrane apparatus and the pressure-rise method. Solubility measurements were obtained using a gravimetric microbalance, and diffusivity was calculated using a Fickian model. The results indicate that a high permeability and selectivity of HFC-32/HFC-125 can be obtained with a 50 wt % PBVE and 50 wt % PDD copolymer and that the separation is diffusion-driven over the entire range of compositions tested.

Feasibility of applying an electrostatic precipitator integrated with a naturally ventilated double-skin façade in residential buildings

One of the main advantages of applying a double-skin façade (DSF) is allowing natural ventilation. As concerns about high outdoor particle concentrations increase, maintaining comfortable indoor air quality through natural ventilation in buildings with DSFs becomes difficult. An electrostatic precipitator (ESP) integrated with a DSF (EPID) has been proposed for maximizing the natural ventilation in buildings with polluted outdoor air. In this study, the particle removal performance and ozone generation of the EPID were experimentally evaluated to determine the feasibility of applying it in residential buildings. An EPID prototype was constructed, and laboratory experiments were performed to measure the single-pass particle removal efficiency and concentration of ozone, a byproduct of the ESP. The results showed that the average particle removal efficiency (77.4 ± 5.5%) at the upper ESP position is similar to that at the lower ESP position (78.5 ± 11.6%) for 0.25–1.82 μm particles at 9 kV applied voltage and 0.5 ms−1 inlet air velocity. When the inlet air velocity increases to 2.0 ms−1, the particle removal efficiency decreases to 39.7% depending on the ESP position. Moreover, the ESP position significantly influences the particle removal efficiency because it changes the inlet air velocity, especially at low applied voltages. Our results highlight the importance of determining the appropriate ESP position in the EPID for residential applications because low-voltage operation is recommended for the safety of occupants and reduction in ozone generation. In addition, at 0.5 ms−1 inlet air velocity, at which the EPID has excellent removal performance, the net ozone concentrations are 33.0 ppb and 35.7 ppb at 6 kV and 9 kV, respectively, which are all lower than the threshold (50 ppb), regardless of the ESP position. The results of this study verify the feasibility of applying the EPID and have important implications for future EPID designs and developing control strategies to improve the indoor air quality of naturally ventilated residential buildings with DSFs.

Aerodynamic upgrades of a Darrieus vertical axis small wind turbine

Wind energy conversion is contributing significantly to the new clean energy transition but, up to now, such contribution is mainly driven by large multi-MW windfarms. On the other hand, the recent needs in terms of distributed energy production are revealing a new interest in small-scale wind energy conversion technologies for residential and urban applications. In this context, vertical axis wind turbines (VAWT) are often the most valid choice from the point of view of building integrating possibilities, but it is well known that they suffer a considerable gap in performance when compared to horizontal axis technologies. Based on these premises, in the present work some innovative solutions for improving the performance of a Darrieus vertical axis wind turbine are investigated through numerical and engineering approaches. The investigated interventions include rotor hybridization by the use of an inner Savonius section for improving the machine’s start-up and the possible application of dimples for improving the NACA 0021 airfoil performances on the outer rotor section. Results demonstrate the effectiveness of the interventions in obtaining a rotor with stable performances in a very wide range of wind regimes.

Fossil-Fuel and Food Systems Equally Dominate Anthropogenic Methane Emissions in China.

Understanding fossil-fuel/food production and consumption patterns is the first step toward reducing the climate impacts of associated methane (CH4) emissions but remains unclear in China. Here, based on the bottom-up method, whole-industrial-chain CH4 emission in China (CH4-CHINA) is developed to track CH4 emissions from production to use and finally to disposal. The estimated Chinese national CH4 emissions in 2020 are 39288.3 Gg (25,230.8-53,345.7 Gg), with 50.4 and 49.6% emissions generated from fossil-fuel and food systems, respectively. ∼130,000 point sources are included to achieve a highly resolved inventory of CH4 emissions, which account for ∼53.5% of the total anthropogenic CH4 emissions in 2020. Our estimate is 36% lower than the Chinese inventory reported to the UNFCCC and 40% lower than EDGAR v6.0, mainly driven by lower emissions from rice cultivation, waste management, and coal supply chain in this study. Based on the emission flow, we observe that previous studies ignored the emissions from natural gas vehicles and residential appliances, coke production, municipal solid waste predisposal, septic tanks, biogas digesters, and food sewage treatment, which totally contribute ∼12.4% of the national anthropogenic CH4 emissions. The results discussed in this study provide critical insights to design and formulate effective CH4 emission mitigation strategies.

Expert system: use of CLIPS software to evaluate solar energy for residences and businesses

The use of energy is important in all sectors, considered essential in industrial, commercial and residential activities. In view of this and the environmental problems caused by energy sources with fossil fuel origin, methods of energy production with renewable sources have been increasingly addressed. Studies that estimate the impact and evaluations of solar technologies in homes are scarce. In this sense, the applied method addresses the use of CLIPS for the development of a knowledge base for preliminary diagnosis and evaluation of solar energy for homes and businesses, thus obtaining a prototype of an expert system, the method also approaches the use of artificial intelligence with a heuristic characteristic and its target audience is people with little or no knowledge in the area, thus contributing to the social impact. As a result, the developed programming helps people with little or no knowledge about solar energy and its residential application to have access and thus verify the applicability. It is worth noting that this is the first empirical study carried out in Brazil, a country of crucial importance for the development of solar energy.

Optimal Sizing and Environ-Economic Analysis of PV-BESS Systems for Jointly Acting Renewable Self-Consumers

Future residential applications could benefit from nanogrids that integrate photovoltaics (PV) and battery energy storage systems (BESS), especially after the establishment of recent European Community directives on renewable energy communities (RECs) and jointly acting renewable self-consumers (JARSCs). These entities consist of aggregations of users who share locally produced energy with the aim of gaining economic, environmental, and social benefits by enhancing their independence from the electricity grid. In this regard, the sizing of the PV and BESS systems is an important aspect that results in a trade-off from technical, economic, and environmental perspectives. To this end, this paper presents an investigation on the optimal PV-BESS system sizing of a condominium acting as a JARSC community, which includes a common PV plant and EMS, operated by rule-based criteria. PV-BESS sizing results are investigated from economic and environmental perspectives, considering a case study located in Milan, Italy. In these regards, in addition to the common techno-economic criteria, carbon dioxide emissions are considered with particular attention, as their reduction is the driving ethos behind recent EU directives.

Experimental testing of platform-type and balloon-type cross-laminated timber (CLT) shear walls with supplemental energy dissipators

CLT technology is gaining notable popularity in both residential and non-residential applications throughout the world, providing a prospective solution to the height limitation of timber buildings. Recently, a growing number of studies have been focusing on energy dissipation strategies for CLT structures since the energy dissipation capacity of CLT structures might sometimes be challenged in seismic design. This paper presents an experimental investigation into the lateral performance of platform-type and balloon-type CLT shear walls with supplemental energy dissipators. Such supplemental energy dissipators are located between coupled CLT wall panels, intending to deform and dissipate energy through the rocking mechanism of CLT shear walls. Two kinds of energy dissipators were adopted, respectively, called O-shaped Flexural Plate (OFP) dissipator and Plate with Openings (PO) dissipator. Quasi-static tests were conducted on four one-third-scale two-story CLT shear wall specimens considering platform and balloon construction methods and these two types of supplemental energy dissipators. The experimental observations, load-displacement responses, energy dissipation capacities, stiffness degradation, and combined single-coupled wall behaviors of the specimens were obtained and compared. The test results showed that the OFP dissipator was quite efficient in dissipating energy, while the PO dissipator exhibited limited energy dissipation capability because it was prone to low cycle fatigue fracture. The supplemental energy dissipators dissipated more energy in balloon-type CLT shear walls compared to those in platform-type CLT shear walls due to the influence of construction methods on the demand of supplemental energy dissipators. In platform-type CLT shear walls, the coupled wall behavior of the walls in the second story was more evident than that of the walls in the first story.

Optimizing the discharge process of a seasonal sorption storage system by means of design and control approach

Sorption thermal energy storage systems have higher energy densities and low long-term thermal losses compared to traditional energy storage technologies, which makes them very attractive for seasonal heat storage application. Although they have a lot of potential at material level, its operation and system implementation for residential application requires further study. The performance of a seasonal sorption thermal energy storage system strongly depends on the discharging process during the cold season. The present study analysed through numerical simulations different scenarios to enhance the thermal performance of a solar-driven seasonal water-based sorption storage, which supplied space heating and domestic hot water to a single-family house in a cold climate region. All studied scenarios were analysed under optimal control policy. The results indicated that the sorption storage could increase by 9 % its energy density if conservative and constant discharging temperature set points are considered, due to fewer interruptions during the discharge. The energy density of the sorption storage driven by solar energy was highly impacted by the weather conditions, and by the type and availability of low-temperature heat source. Indeed, the energy density of the sorption storage increased by 22 % using a water tank to assist the evaporator of the sorption storage, instead of a latent storage tank. The use of a dry-heater to assist the evaporator with environmental heat was not suitable for the climate studied due to the low hours of operation. The sorption storage system composed of 20 modules of LiCl-silica gel could obtain an energy density and a COP of 139 kWh/m3 and 0.39, respectively, if a constant low-temperature heat source (i.e, geothermal or waste energy) was available.

Development and performance assessment of a calcium-iron bromide cycle-based hydrogen production integrated system

In this study, a novel renewable energy-based trigeneration system integrated with a thermochemical cycle is newly developed, analyzed, and evaluated to determine its performance for residential applications. Both solar radiation and wind kinetic energy are harnessed for electricity production. A newly developed biomass-driven thermochemical cycle for hydrogen generation and potential blending with natural gas is analyzed and evaluated accordingly. The blend is then potentially supplied to the gas engine and some residential appliances, such as combi boilers and gas stoves to provide necessary electricity and heat. The heat obtained from the subsystems is employed for residential heating and cooking, as well as for a distillation unit. The reverse osmosis and multi-effect distillation units are both considered in an integrated fashion to produce fresh water for a community considered which consists of 10,000 houses. A total amount of 14.2 million m3 of the blend (with a ratio of 20% of hydrogen and 80% of natural gas) is annually available to potentially utilize for household appliances and gas engines. Furthermore, the present integrated system is analyzed through both energy and exergy approaches. Some parametric studies are then performed for different hydrogen fractions, hydrogen production rates, solar PV areas, wind turbine swept areas, and the number of houses. Moreover, the overall exergetic and energetic efficiencies are determined as 21.02% and 62.61% for the presently developed system.

Substitution of Natural Gas by Biomethane: Operational Aspects in Industrial Equipment

Global gas markets are changing as natural gas (NG) is replaced by biomethane. Biomethane is produced by upgrading biogas, which can have a molar concentration of methane to over 98%. This renewable energy has been injected into the pipeline networks of NG, which offers the possibility to increase its usage in industrial and residential applications. However, the expectation of the increase in biomethane proportion on the NG grids could increase the fluctuations on the composition of the NG–biomethane mixture in amplitude and frequency. In this context, the injection of biomethane into the existing network of NG raises a discussion about the extent to which variations in gas quality will occur and what permissible limits should exist, as variations in combustion characteristics can affect the operation of the combustion processes, with consequences for consumers, distributors and gas producers. This study describes a gas quality analysis with regard to the use of biomethane in industrial equipment, mixed or not mixed with NG, taking into account the indicators for gas interchangeability and provides a discussion on the necessary gas quality level to be achieved or maintained for efficient combustion in equipment originally designed to operate with NG. NG and biomethane real data collected for 92 consecutive days in 2022 and provided by two different companies in Brazil were used for this study. It is shown that the maximum deviation of the Wobbe Index (WI) of 5%, which is allowed for industrial plants, does not work for the operation of furnaces at temperatures of 1200 °C or more. In addition, it is shown that the WI, as defined in relation to the calorific value of the fuel, may allow inappropriate substitution of fuel gases, which is likely to reduce the range of blending of biomethane in NG pipelines. The results can be assessed to analyze how the addition of biomethane to NG grids will impact the WI and the equipment operation parameters such as the air-to-gas ratio, products-to-gas ratio, adiabatic flame temperature and furnace temperature.

Advanced Exergy Analysis of Ultra-Low GWP Reversible Heat Pumps for Residential Applications

Exergy-based methods provide engineers with the best information with respect to options for improving the overall thermodynamic efficiency of an energy conversion system. This paper presents the results of an advanced exergy analysis of an air-to-water reversible heat pump whose performance was analyzed with respect to different working fluids. Environmentally deleterious refrigerants, i.e., R410A and R134a (baselines), and their eco-friendly replacements (R290, R152a, R1234ze(E), and R1234yf) were selected. The evaluations were conducted under the same operating conditions (i.e., with the same cooling and heating demands and outdoor temperatures). Based on conventional exergy analysis, it was determined that different priorities should be given for the thermodynamic improvement of the components according to which heating and cooling modes of the system are in use. Therefore, integrated parameters, i.e., the annual values of exergy destruction, were applied for further analysis. The results obtained showed that the heat pump using R410A provided the largest degree of annual exergy destruction estimated on the basis of conventional exergy analysis (5913 kWh), whereas the heat pump using R290 offered the lowest one (4522 kWh). The annual exergy destruction of the R410A cycle with only unavoidable irreversibilities could be decreased by 50%. In this case, compared to R410A and R134a, R152a and R290 provided lower values of the total annual unavoidable aspects of exergy destruction. Considering technological limitations, when removing all the avoidable irreversibilities within the air exchanger, the largest decrease in the total exergy destruction within the system could be reached. The results obtained from the analysis of the removable irreversibilities showed that the mutual interactions between the compressor, evaporator, and condenser were weak. Finally, it was concluded that, from a thermodynamic point of view, the adoption of R152a and R290 in reversible air-to-water heat pumps as replacements for R410A and R134a is advisable.

Analysis of Boost Converters Fed Grid-Tied PV System

In high solar energy regions, photovoltaic systems are a low-cost source of electrical power. The advantages of a PV system include non-pollution and low maintenance. Solar energy alters irradiance and temperature, and partial shading in the cells is one factor that reduces power output. Therefore, different algorithms are being created to get the most power out of the PV setup, and boost converters are being created to control the supply. DC architectures will be highly sought-after in electrical distribution networks in the future. All of the aforementioned ideas are reviewed in this study for use in DC grids for upcoming DC applications. The idea of a microgrid is quickly becoming recognized as a smart approach to link renewable drive bases and loads. A Direct current grid is essential for the modern domain. Commercial, residential, and industrial applications all increasingly use DC systems. In terms of efficiency, control, and dependability, DC grids are superior. Direct current architectures will be highly sought-after in electrical distribution networks in the future. All of the aforementioned ideas are reviewed in this study for use in DC grids for upcoming DC applications.

An Automated Approach for Screening Residential PV Applications Using a Random Forest Model

The rapid growth of residential solar photovoltaics (PV) applications is a challenge for distribution utilities as they work to maintain grid standards and minimize customer interconnection times. A "screening process" is typically used by utilities to approve customer interconnection request. While conventional "fast-track screening" methods (e.g., limiting PV capacity to 15% of transformer capacity) can be done quickly, they are too restrictive for new PV interconnections. On the other hand, detailed studies often require power flow modeling and would increase customer interconnection times. This work uses a random forest (RF) model to screen residential solar applications without the need for power flow analysis. The proposed RF model is based on commonly available PV application information and network data as inputs, such as application size and solar penetration. The correlation and importance of these RF inputs are investigated so that utilities have flexible implementation options. Further advantages of this data-driven approach are transparency, i.e., utilities can show how different inputs affect a pass/fail decision, and a quantified probability associated with the screening decisions can be provided. Case studies show how a utility would use the proposed approach and benchmark the proposed approach with conventional screening methods. The proposed approach was found to be more accurate than the conventional fast-track screens. It was also found to be faster than detailed power flow studies and nearly as accurate.

Improved utilization of hybrid energy for low-income houses based on energy consumption pattern

<abstract> <p>The adoption of solar photovoltaic and small wind turbine hybrid energy systems in residential applications has picked up promising development around the globe. However, the uncertainty of renewable energy generation associated with the reliance on climate conditions is one of the factors which affect the reliability of the system. Therefore, there is a need to develop an energy management scheme for improving the reliability of the system. One of the drawbacks of hybrid renewable energy systems is the high investment cost, particularly looking at low-income family units. This present paper, an extension of the preceding work, focused on the development of an energy utilization scheme of a hybrid energy system particularly for low-income houses based on energy consumption patterns. The utilization scheme is developed using computational methods in a MATLAB environment. Energy storage systems considered in this work are electrochemical batteries and small-scale flywheel energy storage (kinetic energy storage). Utilizing hybrid energy based on consumption patterns has lowered the capacity of the system's components, resulting in a 0.00 investment cost. The flywheel energy storage is prioritized to supply high-wattage loads while the battery is prioritized to supply average loads, resulting in a 33.9% improvement in battery health. This hybrid system contains a high proportion of renewable energy and reduces annual electricity costs by 96.7%. The simulated results on MATLAB software showed an improvement in terms of energy utilization of a hybrid power system. The cost of utilizing energy is reduced by effectively utilizing more renewable energy sources, with a resultant reduction in electricity bills.</p> </abstract>

Multi-Level Inverter Fed Induction Motors Based on Simplified and Efficient Modulation Techniques

Speed control of three phase and single phase induction motors represents a very important issue in residential and industrial applications. This paper presents a voltage to frequency speed control of both single phase and three phase induction motors derived by multi-level inverters (MLIs). 15-level and 31-level multi-level inverters are considered. Both MLIs are operated by applying two proposed simplified and efficient modulation techniques in addition to the application of conventional multicarrier sinusoidal pulse width modulation technique MC-SPWM. The proposed modulation techniques overcome several difficulties related to MC-SPWM. The scaler voltage to frequency control method operates very well during starting along with step changes in motor speeds. Simulation results verify the high performance of the proposed modulation techniques when controlling both induction motors based on 15-level and 31-level MLIs.

Secure Home Calling Bell

The Secure Home Calling Bell focuses on home security, a very beneficial IoT application that they are leveraging to develop a low-cost security system for residential and commercial applications. An ESP32 cam, ESP32 board, a flame sensor, and a PIR sensor are the components of the project. When a visitor approaches the door, the secure house project's initial phase sends the user a notification that reads, "Someone's At Your Door." An ESp32 camera that would be connected to a calling bell for surveillance whenever the user's notification was received makes up the project's next step. An additional component of the IoT project is a flame sensor-based fire alarm system.

Average Current Control with Internal Model Control and Real-time Frequency Decoupling for Hybrid Energy Storage Systems in Microgrids

Among hybrid energy storage systems (HESSs), battery-ultracapacitor systems in active topology use DC/DC power converters for their operations. HESSs are part of the solutions designed to improve the operation of power systems in different applications. In the residential microgrid applications, a multilevel control system is required to manage the available energy and interactions among the microgrid components. For this purpose, a rule-based power management system is designed, whose operation is validated in the simulation, and the performances of different controllers are compared to select the best strategy for the DC/DC converters. The average current control with internal model control and real-time frequency de-coupling is proposed as the most suitable controller according to the contemplated performance parameters, allowing voltage regulation values close to 1%. The results are validated using real-time hardware-in-the-loop (HIL). These systems can be easily adjusted for other applications such as electric vehicles.