Residential Applications Research Articles

Cost effective 24-h radiative cooler with multiphase interface enhanced solar scattering and thermal emission

Passive radiative cooling is an emerging energy-free pathway that radiates the emission of heat from the earth to cold space (3 K) through an atmosphere transparent window (7–14 µm). Recently, this technology has attracted great interest in residential and industrial applications. However, critical challenges remain for 24-h radiative cooling due to the unwanted solar heating effect in the daytime. The complex manufacturing process and high price also result in a cost barrier for large-scale applications. Here, an easy-prepared and cost-effective radiative cooler (RC) was processed which consists of polydimethylsiloxane (PDMS) and SiO2 microspheres based on cellulose nanofibers (filter paper) with a backing silver (Ag) mirror for mass production. This whitish hybrid material exhibited high reflectance of 91% in the AM 1.5 solar spectrum (0.2–2.5 µm) and high thermal emissivity of 90% in the atmospheric window, which was enhanced by the randomized multiphase interfaces. Moreover, it can accomplish 24-h continuous outdoor cooling with an efficient average temperature reduction of 5 °C, especially 6.5 °C in the nighttime. Overall, this work provided a new approach to promote 24-h radiative cooling as a next-generation green energy technology.

A Novel Polygeneration System Based on a Solar-Assisted Desiccant Cooling System for Residential Buildings: An Energy and Environmental Analysis

This work aims to design and dynamically simulate a polygeneration system that integrates a solar-assisted desiccant cooling system for residential applications as an alternative to vapor compression systems. The overall plant layout supplies electricity, space heating and cooling, domestic hot water, and freshwater for a single-family townhouse located in the city of Almería in Spain. The leading technologies used in the system are photovoltaic/thermal collectors, reverse osmosis, and desiccant air conditioning. The system model was developed and accurately simulated in the TRNSYS environment for a 1-year simulation with a 5-min time step. Design optimization was carried out to investigate the system’s best configuration. The optimal structure showed a satisfactory total annual energy efficiency in solar collectors of about 0.35 and about 0.47 for desiccant air conditioning. Coverage of electricity, space heating and cooling, domestic hot water, and freshwater was 104.1%, 87.01%, 97.98%, 96.05 %, and 100 %, respectively. Furthermore, significant ratios for primary energy saving, 98.62%, and CO2 saving, 97.17%, were achieved. The users’ thermal comfort level was satisfactory over the entire year. Finally, a comparison with an alternative coastal site was performed to extend the polygeneration system’s applicability.

A deep reinforcement learning-based approach for the residential appliances scheduling

This paper investigates the optimal real-time residential appliances scheduling of individual owner when participating in the demand response (DR) program. The proposed method is novel since we cast the optimization problem to an intelligent deep reinforcement learning (DRL) framework, which avoids solving a specific optimization model directly when facing dynamic operation conditions induced by the outdoor temperature, electricity price and resident’s behavior. We consider the scheduling of power-shiftable, time-shiftable and deferrable appliances for the optimization of profit and satisfaction rate of resident. The optimization problem is first modeled as a Markov decision process and then solved by a model-free entropy-based DRL algorithm. Unlike traditional model-based methods which rely on accurate knowledge of parameters and physical models that are difficult to obtain in practice, the proposed method can develop real-time near-optimal control behavior by interacting with the environment and learning from data, which avoids the error caused by the simplification and assumption when building physical model. The proposed scheduling algorithm also achieves better tradeoff between the profit and the satisfaction rate than deterministic DRL algorithm owing to the introduction of the entropy term. Simulation results using real-world data demonstrate the effectiveness of the proposed method.

Development and assessment of renewable hydrogen production and natural gas blending systems for use in different locations

AbstractIn this study, a thermoeconomic assessment of renewable energy‐based hydrogen generation and blending it with natural gas in the existing pipeline system is performed for various locations. Selected locations are compared in energy content, environmental impact, and cost. In this regard, solar photovoltaic panels and wind turbines are integrated with electrolyzers along with the reverse osmosis units. The clean hydrogen produced by the electrolyzers is then blended with natural gas and utilized for residential applications in an environmentally benign way. Also, the heat required for a community consisting of 100 houses is provided by a boiler by hydrogen and natural gas blend as fuel. The costs of capital, fuel, operation and maintenance are calculated and comparatively evaluated. The results show that the total net present costs for the integrated systems are calculated to be between $3.01 million and $4.36 million in the selected five different locations. Furthermore, an environmental impact assessment is conducted in terms of carbon monoxide, carbon dioxide, nitrogen oxides, unburned hydrocarbons, and particulate matter. Finally, the CO2 emissions are calculated to be varying from 443.2 to 491.9 tons/year.

Low Voltage Direct Current Supplies Concept for Residential Applications

Low Voltage Direct Current (LVDC) Photovoltaic (PV) systems are considered suitable solutions for increasing the capacity of existing LV networks. They provide a good power quality, renewable energy source compatibility, and simple integration with batteries. This paper compares the proposed LVDC supply concept with existing traditional PV systems regarding energy efficiency. The proposed LVDC Photovoltaic System was realized. The results obtained from this study revealed that using the LVDC system supply concept, instead of Low Voltage Alternative Current (LVAC) ones, is very interesting if the PV-generated electricity is used locally during day hours. To achieve a high PV system efficiency, the PV power installed in the houses should be accurately sized regarding the consumed energy. The shorted path taken by the PV-generated power to feed load during daytime is the main advantage of the proposed LVDC architecture.

Comparative transient simulation of a renewable energy system with hydrogen and battery energy storage for residential applications

Energy systems for the building sector nowadays are moving towards using renewable energy sources such as solar and wind power. However, it is nearly impossible to fully develop a multi-generation energy system for a building only relying on these sources without convenient energy storage, backup systems, or connection to the grid. In this work, using TRNSYS software, a model was developed to study the transient behavior of an energy system applicable for residential buildings to supply the heating, cooling, domestic hot water, and electricity in demand. This study contains the comparison of two methods of energy storage, a hydrogen fuel cell/electrolyzer package and a conventional battery system. This study also provides information on environmental impacts and economical aspects of the proposed system. The results show that for an HVAC system when using hydrogen storage system the capital cost is twice the cost of using a battery system. However, the hydrogen system shows better performance when used at higher loads. Hydrogen storage systems show higher performance when used at higher size units.

Assessment of hydrogen as a potential energy storage for urban areas’ PV-assisted energy systems - Case study

The world is experiencing unprecedented development in the clean energy sector in residential and industrial applications. This paper provides a case study assessing different scenarios of greenizing the electrical energy demand in El-Mostakbal city in Egypt. Three scenarios are studied with consideration of a photovoltaic (PV) system integrated with the grid-connected city with different integrated system configurations. The scenarios for the grid-connected city are scenario-I: only PV, scenario-II: PV with batteries for electricity storage along with grid electricity, and scenario-III: PV with hydrogen production, storage, and utilization for covering the electric demand along with grid electricity, these scenarios are assessed technoeconomically, and the results show an optimized case where the electricity demand of the city can be met with 64.3% produced from solar energy, at $71.7 M of the net present cost.

Device Access Optimization for Virtual Power Plants in Heterogeneous Networks

In virtual power plants (VPPs), distributed devices (such as residential appliances, energy storage, and electric vehicles) communicate with control centers via wireless access points (APs). Nevertheless, with a massive number of devices connected to APs, VPPs would be adversely affected by packet loss and consequently suffer from revenue reduction. Therefore, devices’ access connections need to be delicately designated to mitigate these negative impacts. This paper studies the device access optimization problem from the perspective of VPP operations. An optimization model to minimize the revenue reduction induced by packet loss is first formulated to designate APs for devices in heterogeneous communication networks. The significance of various device data is determined by revenue reduction as a result of packet loss. Additionally, the heterogeneous access network model is established to characterize different types of APs. To make the model implementable, this paper further proposes a layered decomposition solution algorithm, which decomposes optimization tasks into small-scale sub-problems and successively assigns them to different layers of APs. Sub-problems are further decomposed for APs to greedily cut revenue reduction by evaluating devices’ marginal contributions to revenue reduction. Numerical case studies are also conducted to verify the benefits of device access optimization.

Development of fire safety best practices for rooftops grid-connected photovoltaic (PV) systems installation using systematic review methodology

• Installation of PV system as green energy initiative is showing a rising trend. • Poor installation practices of PV system by installers have resulted in PV fires. • Collation of best fire safety practices for rooftop PV system installation. • A systematic review to scrutinize aspects of fire safety in PV system installation. • Fire safety checklist is suggested to be part of PV system installation guidelines. Numerous photovoltaic (PV) fire incidents are caused by overheating of PV system components, direct current (DC) arc-fault or hot spot phenomenon. These causes happen mainly due to poor installation practices by the installers. Many PV system installation guides do not emphasise much on the fire hazard during installation. As the PV system is becoming increasingly popular nowadays, it is crucial to establish a specific and comprehensive guideline pertaining to fire safe installation of the system. Therefore, this paper aims to assess and incorporate such fire safety practices from all PV installation guidelines that are publicly accessible. A total of 40 PV installation publications have been systematically reviewed and classified into two categories – design consideration and installation stage. The analysis pointed out a compilation of fire safety practices during PV system installation focusing on residential rooftop applications from the reviewed publications. Although DC isolators have been reported as the top component of PV fire causes, many guidelines do not emphasise the fire hazards involved as well as the things that should and should not be done during installation. The inclusion of a fire safety checklist is suggested as part of the installation guideline.

TDM-PON-Based Optical Access Network for Tactile Internet, 5G, and Beyond

An optical access network plays a critical role in accommodating explosive new services such as augmented reality (AR), virtual reality (VR), machine-to-machine, and human-to-machine interaction applications. Continuous expansion of capacity as well as low latency in the optical access network are very important issues to avoid loss of connectivity for 5G and Tactile Internet. A time-division multiplexing passive optical network (TDM-PON) is an attractive solution to provide optical connectivity to end users in residential, business, and mobile applications since multiple remote nodes with simple optical power splitters give us easy-to-use optical connection anywhere in an optical distributed network. This article reviews TDM-PON-based optical access technologies for bandwidth-intensive as well as low-latency services, and introduces a recent feasibility demonstration of a Tactile Internet testbed. Technical challenges faced by TDM-PON for future networks in terms of capacity, latency, and virtual-izationlslicing are also discussed.

Application of Magnesium Oxide Media for Remineralization and Removal of Divalent Metals in Drinking Water Treatment: A Review

The post-treatment of soft and desalinated waters is an integral step in the production of quality drinking water. Remineralization is therefore often essential in order to stabilize the effluent for distribution and to attain mineral levels that fulfill aesthetic and health goals. According to the World Health Organization, magnesium (Mg2+) is a nutrient essential to human health. This review summarizes the effectiveness of magnesium oxide (MgO) media for soft water remineralization, as well as its potential for divalent metal removal (e.g., Mn, Cu, and Zn), which is of particular interest in small or residential applications. We present MgO sources, properties, and dissolution mechanisms. Water treatment applications are then reviewed, and the available design models are critically appraised in regard to remineralization and contaminant removal processes. In addition, we review the process operation challenges and costs. Finally, we discuss the use of MgO in combination with calcite and address the technical advantages and limitations compared to other available methods.

Numerical Simulation of an on-Grid Natural Gas PEMFC - Solar Photovoltaic Micro CHP Unit: Analysis of the Energy, Economic and Environmental Impacts for Residential and Industrial Applications

As global natural resources depletion and concern on emission of greenhouse gases intensify, the interest for low emission technologies and the use of renewable energy increased in the world. In this context, this paper aims to present an hybrid energy system for on-grid micro residential and industrial applications. The system is composed of a micro combined heat and power (CHP) unit, including a natural gas (NG) reformer coupled with proton-exchange membrane fuel cell (PEMFC), solar photovoltaic modules (PV) and a bank of batteries (B), connected to the grid through a bidirectional inverter. Different system configurations (PEMFC + PV + B, PEMFC + B, PEMFC + PV), with or without cogeneration of the heat from the CHP system, were investigated to calculate the required NG and electricity flows and assess the economic cost during 10 years of operation in an 2020–2040 horizon. The impact of fuel cell sizing and two electricity tariffs was also assessed for both applications. Afterwards, the cash flow in terms of net present value of a 20 years operation period was simulated within the Brazilian context, yielding estimated paybacks between 7 and 19 years for the simulated cases. Finally, an environmental impact analysis was carried out to investigate the total GHG emissions for some cases of interest in this work. The proposed system could reduce total emissions up to 31% when compared to the complete power and thermal supply by the Brazilian Electricity grid and natural gas heater The results showed that the proposed system were economically viable, relatively low-polluting and more efficient than traditional PV systems.

Modeling of a Grid-Independent Set-Up of a PV/SOFC Micro-CHP System Combined with a Seasonal Energy Storage for Residential Applications

Renewable energy sources based on solar and wind energy provide clean and efficient energy. The intermittent behaviour of these sources is challenging. At the same time, the needs for efficient, continuous and clean energy sources are increased for serving both electricity and thermal demands for residential buildings. Consequently, complimentary systems are essential in order to ensure a continuous power generation. One of the promising energy sources that helps in reducing CO2 emissions, in addition to providing electrical and thermal energy efficiently, is a Solid Oxide Fuel Cell (SOFC) system operated in a combined heat and power (CHP) mode, due to high electrical efficiencies (in full and part load) and the fuel flexibility. Currently, most studies tend to focus on fuel cell model details with basic information about the building’s energy requirements. Nevertheless, a deep understanding of integrating fuel cell micro-CHP systems with renewable energy systems for the residential sector is required. Moreover, it is important to define an operating strategy for the system with a specific controlling method. This helps in evaluating the performance and the efficiency of the building energy system. In this study, an investigation of different configurations of a hybrid power system (HPS) was carried out. The intended aim of this investigation was to optimize a HPS with minimal CO2 emissions, serving the energy demands for a single-family house efficiently and continuously. As a result of this study, a photovoltaic (PV)/SOFC micro-CHP system has satisfied the intended goal, where the CO2 emissions are significantly reduced by 88.6% compared to conventional systems. The SOFC micro-CHP plant operated as a complimentary back-up generator that serves the energy demands during the absence of the solar energy. Integrating the Power to Gas (PtG) technology leads to a similar emission reduction, while the PtG plant provided a seasonal energy storage. The excess energy produced during summer by the PV system is stored in the fuel storage for a later use (during winter). This SOFC micro-CHP configuration is recommended from an energy and environmental perspective. In terms of feasibility, the costs of SOFC based micro-CHP systems are significantly higher than traditional technologies. However, further technology developments and the effect of economy of scale may cause a substantial drop in costs and the micro-CHP shall become economically competitive and available for residential users; thus, enabling a self-sufficient and efficient energy production on site.

COMPARATIVE ANALYSIS OF BATTERY STORAGE TECHNOLOGIES FOR RESIDENTIAL PHOTOVOLTAIC SOLAR ENERGY INSTALLATIONS

The study concerns a comparative analysis of battery storage technologies used for photovoltaic solar energy installations used in residential applications. Battery storage is needed because of the intermittent nature of photovoltaic solar energy generation and also because of the need to store up excess energy generated in periods of high demand or for sales to the National Grid System. The study consists of three parts; namely: (a) to undertake a comprehensive review of current battery storage technologies. (b) To investigate the performance of the main battery storage technologies that is commercially available (efficiency, energy density, power density, self-discharge per day and power rating); (c). Undertake comparison of battery energy storage technologies. From the findings, it shows that the Lithium Ion Battery technology is the most reliable and most widely used technology for residential applications. It has the best performance characteristics (efficiency, energy density, power density, moderate self-discharge and power rating) however, lithium ion batteries are still relatively expensive among others. Due to these features the Lithium Ion Battery technology stands a total chance of dominating the Battery technology market for residential and automotive applications. Also shows from the findings, the performing reliability of the Lithium ion battery by using the battery application requirements and the dangers in operating at a not required specification. More recommendations were made in areas of challenges faced by the battery storage technologies in order to make improvement.

Thermoeconomic and impact assessments of trigeneration systems with various fuels

In this paper, both renewable hydrogen production and blending with natural gas for the existing distribution pipelines are studied through a unique trigeneration systems development, analysis, and assessment. A comparison with various conventional fuels, such as diesel, coal, biogas, and biodiesel is provided. In this regard, solar and wind energy-based power systems integrated with reverse osmosis units are designed and compared in energy, exergy, environment, and cost. Solar PV panels and wind turbines are considered for electricity generation. For hydrogen-based systems, an electrolyzer is utilized to produce hydrogen. The heat demands needed for residential applications are also provided in an environmentally benign way. Here, electricity, heat, and freshwater needed in a community consisting of 100 houses are provided. The costs of capital, fuel, operation, and maintenance are calculated and evaluated in detail. Furthermore, an environmental impact assessment is performed by comparing carbon monoxide, carbon dioxide, nitrogen oxides, sulfur dioxide, unburned hydrocarbons, and particulate matter. In closing, both energy and exergy efficiencies of hydrogen and natural gas mixture-based (NG-80% and H2-20%) integrated systems are calculated as 27.47% and 37.43%, respectively.

A hybrid precast concrete stiffened wall substructure for residential construction on expansive soils

The use of precast systems reduces material wastage, decreases effect of weather impacts, cuts down unexpected costs, lessens skilled labour dependence and minimises construction hazards. However, the full potential of precast construction is yet to be realised in part due to most advancements being focused on its superstructure. Development of precast substructures or foundation systems for lightweight buildings, such as residential structures, needs to consider functionality and susceptibility to damage induced by the swelling movement of expansive soils causing significant structural damage and financial loss. Due to this, the main objective of this paper is to assess the ultimate strength and serviceability of a developed precast concrete wall substructure using full-scale laboratory testing and coupled finite element modelling, respectively. This study evaluates a developed hybrid precast concrete stiffened wall substructure using laboratory experiments and numerical simulations to determine its ultimate strength and serviceability, respectively. The innovative design of the developed precast substructure satisfied functional requirements for residential construction application. The slab and rib portions of the developed substructure had an acceptable ultimate strength with failure observed at 4.5 times the factored load equivalent and 2.6 times the factored load equivalent, respectively. Moreover, the developed precast system due to its configuration had reduced the active depth of expansive soils prone to moisture changes, the vertical soil movement around the prefabricated footing, and the deformation experienced by the system.

Off-grid hybrid photovoltaic – micro wind turbine renewable energy system with hydrogen and battery storage: Effects of sun tracking technologies

The residential application of renewable energy is on the rise in sub-Saharan Africa with many of these systems using battery storage systems as back-ups; however, the adoption of hydrogen storage systems in household energy system applications has attracted few research attentions. Since the environmental impact attributed to hydrogen storage devices is small, it can serve as a complementary or alternative storage device. Using the hybrid optimisation model for electric renewables software, this study presents a techno-economic and sensitivity modelling of a solar photovoltaic (PV)/micro wind turbine/ fuel cell (FC) energy system backed up with both battery and hydrogen storage devices, under seven solar photovoltaic tracking orientations. Because of their strategic status in sub-Saharan Africa, one location each in South Africa and Nigeria were selected for the implementation of the study. The results show that the optimal energy system for the Nigerian scenario is a PV/FC/electrolyzer/battery/hydrogen storage system operated in the daily adjusted horizontal axis mode; the total net present cost and the cost of energy for this system is $9421 and $0.754/kWh respectively. As for the South African scenario, the optimal system is also a PV/FC/electrolyzer/battery/hydrogen storage system operated in the dual axis mode; its total net present cost and the cost of energy for the system is $8771 and $0.701/kWh respectively. Overall, the results show that the addition of a hydrogen storage system is technically feasible for most of the sun tracking configurations in both locations of study. Finally, the economic viability of hydrogen storage systems will be increased if the capital costs associated with the hydrogen sub-system is reduced.

Solar-Powered Reverse Osmosis Desalination

With the dimension of renewable energy and resources from the earth, solar power has come as a bundle of a package for energy production by using PV solar cells for residential applications. Extension of freshwater from the earth produces water near a city in different parts of the worldwide is the serious problem especially in North African countries and the Middle East. So, for the survival of humanity, desalination is a necessity for the living and with the use of natural energy i.e., plenty of sunshine coming from the sun. With recent advancements in technology in the field of solar power & improving the design of energy conversion systems operating on solar energy harvesting & converting it into electricity with the help of thermopiles. The major focus is on designing & designing parameters with the overall performance enhancement of the proposed energy conversion system. Nowadays, solar energy can also be employed independently or with fossil fuels to reduce CO2 emission & the Levelized cost of power generation. But with the advancement of the supercritical Brayton cycle also informs the prospects of lower Levelized cost for higher efficiency at accessible temperature.

Design of Battery management system for Residential applications

Battery management system plays an important role for modern battery-powered application such as Electric vehicles, portable electronic equipment and storage for renewable energy sources. It also increases the life-cycle of the battery, battery state and efficiency. Monitoring the state of charge of the battery is a crucial factor for battery management system. This paper deals with monitoring the state of charge of the battery along with temperature, current for Solar panel fitted with battery for residential application. Microcontroller is used for controlling purpose, analog sensors are used for sensing the parameters of voltage, current. The information of the battery is given with tabular form and shown in photograph. Battery parameters are displayed with the LCD screen.

Social life-cycle assessment (S-LCA) of residential rooftop solar panels using challenge-derived framework

BackgroundSocial life-cycle assessment (S-LCA) provides a framework to evaluate the social impacts of decisions made during the design phases of a product. Rooftop solar panels are considered an environmentally friendly renewable energy technology due to their ability to generate electricity without producing greenhouse gases while generating electricity. This study presents the application of a challenge-derived S-LCA framework to assess the social impacts of rooftop solar panels in the southeast region of the United States (U.S.) during the use and end-of-life phases.MethodsThe challenge-derived S-LCA framework was developed based on a set of challenges to performing social assessments. The challenges were identified through a systematic mapping process and verified using expert feedback. Additional feedback is gathered through users from mechanical engineering capstone design students. The case study application shown in this paper aims to identify the potential social impacts at a pre-implementation stage of the rooftop solar panel in residential applications. The framework follows the ISO 14040 LCA structure, and the analysis was performed based on impact indicators (Type-I framework) and performance reference points (PRP).ResultsThe framework implements existing social impact assessment methodologies, and guides each of the assessment stages based on the type of analysis performed. The results highlight the workers as the stakeholder group with the highest social impacts. The results also highlight the need for regulation to make rooftop solar panels accessible to low-income community members.ConclusionsAn S-LCA framework to assess the social impacts of product systems and technologies is implemented to evaluate the potential social impacts of residential rooftop solar panels. The framework presented applies to product systems and technologies at a pre- or post-implementation state, and it aims to guide novice and expert users alike. Nonetheless, further research is still needed to improve the methodology presented, and additional case studies should be performed to test the applicability of the framework across a broad set of fields.