Payback Period Research Articles

Techno economic analysis of PV pumping system for rural village in East Java

Renewable energy systems offer a sustainable alternative for addressing energy needs, especially in rural settings. This study investigates the optimization of a hybrid photovoltaic (PV) pumping system by minimizing the Cost of Energy (COE), maximizing the Renewable Fraction (RF), and reducing Carbon Dioxide Emissions (ECO₂). The optimization process was carried out using Python to implement the Queen Honeybee Migration (QHBM) algorithm, which evaluated three distinct scenarios to determine the most efficient system configuration. The optimal setup comprised 48 units of 600 Wp PV panels, 17 units of 250 Ah batteries, and 3 units of 8,000 W inverters. This configuration achieved a COE of $0.041 per kWh, an RF of 43.96 %, and an ECO₂ reduction of 118.49 kgCO₂e, with a cumulative objective value of -146.76. A comparative analysis with the Particle Swarm Optimization (PSO) algorithm indicated that QHBM excels in optimizing RF and ECO₂, whereas PSO demonstrates marginally superior performance in reducing COE. The economic evaluation reveals a Net Present Value (NPV) of $40,206.11 over a 35-year period, a Return on Investment (ROI) of 398 %, a Break-Even Point (BEP) of 6.45 years, and a Payback Period (PP) of 13.25 years. The system is projected to yield daily and annual cost savings of $6.33 and $2,310.90, respectively. These results underscore the efficacy of QHBM in achieving superior techno-economic and environmental performance in hybrid PV pumping systems.

Ethanol from Bagasse Obtained During Non-centrifuged Sugar Production. A Comprehensive Sustainability Analysis in the Colombian Context

AbstractThe production of biofuels is an alternative to reduce the impacts of the transformation of fossil fuel sources. In this work, the evaluation of ethanol production from the bagasse obtained during non-centrifuged sugar production (BNCS) to determine its sustainability in the Colombian context is proposed. Two pretreatments (i.e., dilute acid and alkaline) are proposed, followed by enzymatic saccharification to release glucose from cellulose. Both liquors rich in C6 sugars were followed by a fermentation stage with Saccharomyces cerevisiae, and the obtained ethanol concentration was measured. The process was simulated and evaluated to obtain metrics in technical, economic, environmental, and social terms. Also, an evaluation of the sustainability index of the process in the Colombian context was proposed. Diluted acid was the best processing pretreatment, reaching glucose and xylose concentrations of 15.13 g/L, and 12.15 g/L respectively, and a final ethanol concentration of 3.45 g/L. The technical analysis yielded results for Process Mass Intensity (PMI) of 38.14 and Renewable Material Index (RMI) of 5.09. The minimum process scale for economic feasibility (MPSEF) was 19.6 Ton/h. In this sense, the payback period and turnover ratio were 12 years and 35.01%, respectively. Values of 1.85 kg CO2 eq/kg ethanol for carbon footprint and 1.02 m3/kg ethanol for water depletion were also obtained. For the social analysis, the minimum-to-living wage ratio (M/L) was 1.03. Finally, the sustainability index was 75.19%, and the social and environmental values were the most influential aspects affecting the sustainability index. The results of this work allows a novelty vision related to the integral analysis of sustainability for one of Colombia’s native raw materials, and to propose viable solutions for its use, without threatening food security. Graphical Abstract

Techno-economic design and placement tool for energy recovering pressure regulating turbines in water distribution systems

Water distribution systems present poor energy efficiency due to the significant amount of energy that dissipates in the form of excess water pressure. Besides energy losses, excess pressure increases water losses due to leakages and may result in pipeline damage. The employment of micro-turbines that concurrently harness excess energy and achieve pressure management is proposed by many researchers as potential replacements to the currently used pressure reduction valves. This work relies on previous work that determines the optimal design and operating point of such turbines integrated in the power distribution system, in order to develop an algorithm that considers the economic viability of such projects. The suggested algorithm has been applied to a simulated large-scale WDS in Kentucky that contains several locations where pressure regulation is currently performed or planned due to immense local pressure. Involving the economic viability of pressure regulating turbines within the design optimization process improves pay-back period and levelized cost of energy by more than 10 % and 20 %, respectively, compared to when their design is optimized solely for pressure regulation and maximum energy yield. The application of this approach to a typical WDS allowed more than 161 MWh/year of clean energy to be produced.

Rapid investment casting: a techno-economic analysis for evaluating VAT photopolymerisation processes

Adopting additive manufacturing in investment casting, known as rapid investment casting, can significantly reduce lead time and cost. Despite many publications on these technologies, no quantitative techno-economic analyses refer to rapid investment casting. The paper provides helpful insights and a decision-making approach for replacing conventional production technologies (i.e. wax injection) with additive manufacturing technologies. The study is based on a techno-economic analysis framework. It allows assessing key performance indicators (e.g. crossover points and payback periods) for stakeholders to decide the suitable VAT photopolymerisation processes (i.e. stereolithography, digital light processing, and material jetting) according to specific production scenarios (i.e. load factors). Analytical cost models were developed in the frame of this work to assess the time and cost of the overall manufacturing process of the resin model for investment casting, considering the post-processing stages for each of the technologies investigated. The cost models were used to assess the benefits introduced by additive manufacturing in rapid investment casting. A sensitivity analysis evaluated the impact of energy, material, and labour costs for both key performance indicators (crossover points and payback periods). The techno-economic analysis yielded the following results: (i) crossover points in terms of production costs vary, ranging from thousands of units for small components in the jewellery or fashion industries to a few dozen units for larger parts in the mechanical industry, and (ii) crossover points in terms of time are lower than those related to cost. Additionally, digital light processing is regarded as the most promising technology, offering the best crossover points and payback periods across various scenarios, mainly when 3D printers are used at a low utilisation rate.

AMI water meters deliver end-use water and financial savings in leaky households: experimental evidence from California

Abstract Advanced metering infrastructure (AMI) for residential water consumption is exploding globally giving water utilities the ability to improve their water tracking, billing, and distribution systems’ leak detection. With AMI, utilities have also gained the opportunity to provide real-time high-resolution water consumption information to their customers to induce conservation. Using a randomized controlled trial we find that on average homes that install AMI and receive conservation based messaging significantly reduce water consumption by 5.24 gallons per household per day beyond savings already obtained from home water reports. Of the estimated water savings we attribute 92.8% to leak reduction. While the payback period from the deployment of AMI meters and treatment in all homes is over 41 years, homes that experience leaks realize financial savings of $60/year and a treatment payback period of four years. This is because treatment did not induce water or financial savings in homes without leaks. These findings indicate that even on top of existing conservation programs, AMI messaging that targets end-user leaks could result in significant water savings, economic benefits to end-users, and advance conservation goals.

A novel bio-coagulation/co-digestion/pyrolysis scheme for banana pseudostem waste management: techno‑economic and sustainability approaches.

While several studies have focused on utilizing banana pseudostem waste (BPW) for wastewater treatment via bio-coagulation, this process still suffers from secondary pollution caused by the disposal of generated sludge. To avoid this pollution transfer issue, this study is the first to focus on the recyclability of post-coagulation sludge (PCS) to recover added-value products. For this purpose, BPW was used as a model bio-coagulant for the decontamination of laundry wastewater (LWW), followed by anaerobic digestion and pyrolysis schemes to recover biogas and biochar, respectively. In the first experiment, BPW succeeded in removing 55.44 ± 1.21%, 90.40 ± 3.09%, and 78.13 ± 2.44% of chemical oxygen demand (COD), turbidity, and surfactant, respectively, at the optimized condition (pH = 3.5, dosage = 2.34 g/L, stirring speed = 160.6 rpm, and settling time = 55.5 min). Inoculating the spent bio-coagulant with cattle manure (CM), with a mixing ratio of 1:1 (w:w), showed a biogas yield of 110.33 ± 6.02 mL/g COD. The synergetic effect of spent coagulant and microbes of CM was further validated by performing a COD mass balance, showing that about 31.52 ± 1.63% of CODfeed was converted to bio-CH4 (as COD). Further, the thermal treatment of digestate was successfully employed for biochar recovery at a yield of 0.58 ± 0.05 g biochar/g dry digestate. The study also revealed that the triple LWW treatment/biogas/biochar strategy could gain economic benefits with a payback period of 4.4 years. Hence, BPW could be used as a promising feedstock for pollution reduction, energy generation, and gaining profits.

Sustainability analysis of apple orchards: Integrating environmental and economic perspectives

The agricultural sector faces numerous challenges today, including the protection of biodiversity and the mitigation of environmental impact. Addressing these challenges require ensuring the stability of farmers' income, thus facilitating effective land management.The present study aims to evaluate the environmental and economic sustainability of apple orchards under two distinct systems (integrated versus organic) and a scab-resistant variety. The Life Cycle Assessment method (LCA) was employed to evaluate environmental impact, while financial and economic aspects were analysed using metrics such as Net Present Value (NPV), Equivalent Annual Value (EAV), Benefit-Cost Ratio (B/C) and Discounted Payback Period (DPP).Results analysis reveals that both inorganic fertilisation and pesticides usage have the greatest impacts in both integrated cultivation and scab-resistant orchards. In organic orchards, diesel usage emerges as a primary factor due to the substitution of chemical interventions with mechanical methods. For the same reason, labour constitutes 45 % of the organic production costs. Despite the lower environmental impact, organic treatments still contribute 22 % of the total production cost. Regarding the investment evaluation, the scab-resistant variety offers marginally lower costs than conventional varieties due to the reduction of required treatments; however, organic farming shows superior economic performance despite higher production costs, mainly attributed to higher market prices. This highlights the influence of market dynamics on business decisions in the apple sector, where farmers often have no direct control.

Determining the efficiency of local heat recycling wastewater based on a heat exchanger

RELEVANCE. The authors research the potential energy, economic and environmental effects of using local heat recovery from wastewater generated in showers. At the moment in Russia, almost all household wastewater is disposed of in sewer networks without the beneficial use of the heat that they possess. It is important to determine the effect of implementing this method of heat recovery, to identify and analyze the problems that prevent this from being done.THE PURPOSE. The purpose of the work is to determine the potential effect of using local heat recovery from wastewater generated in showers.METHODS. Based on a verified mathematical model of the heat exchanger, the energy effect from the individual use of the shower room is determined. A number of assumptions are applied to the heat consumption structure of an individual building and, based on available data on the average annual heat consumption of residential buildings in Moscow, the economic and environmental effect of energy-saving measures is calculated.RESULTS. Relative savings within the annual heat consumption of a building with a decentralized and centralized hot water supply system were 5,3% and 3,1%, respectively (64 and 37 GCal). Fuel economy amounted to: 9145 toe and 5227 toe for a building with a decentralized and centralized hot water supply system, respectively (14,5 and 8,5 thousand tons of CO2-eq). The payback period for energy-saving measures for the case of a decentralized hot water system based on an instantaneous electric water heater was 1,5 years.CONCLUSION. Local waste heat recovery makes it possible to obtain a significant energy and environmental effect within any locality, but at the moment there are no measures to support consumers implementing energy-saving measures. Currently, this method of heat recovery is of interest only to those consumers whose source of thermal energy for the needs of hot water supply is electricity.

Comparative study on productivity of double slope solar still using different wick and energy storage materials

The aim of the proposed study is to evaluate the efficiency of Double Slope Solar Still (DSS) using different wick and energy storage materials. In the study, wick materials such as jute, cotton and sponge were used in combination with energy storage materials such as mild steel, cast iron and copper. The experiments were conducted using DSS with different combinations of wick and energy storage materials to determine the efficient performance combination. The results show that sponge and copper have higher efficiency with wicks and energy storage materials. The results show that the maximum amount of water produced in a single day was 3147 ml when the DSS system was used with a combination of sponge and copper materials. This range shows an increase of 17.47 % and 12.44 % over the DSS with jute and copper and the DSS with the combination of cotton and copper respectively. The DSS showed the highest average energy efficiency when used in conjunction with a combination of sponge and copper, namely 51 % of the average efficiency. This corresponds to an increase of 18.60 % and 10.86 % compared to the combination of DSS with jute and copper and the combination of DSS with cotton and copper respectively. The best evaporation heat transfer coefficient of 345 W/m2K was determined for the combination of DSS with sponge and copper. Average exergy efficiency is also maximum of 3.076 % for the DSS with sponge and copper materials, which is higher than other investigated combinations. The proposed system has an energy payback period of 1.26 years, an energy production factor of 0.78, a life cycle efficiency of 6.9 % and a cost of $0.031 per litre of water produced in the environmental economic analysis.

Experimental analysis of solar desalination system performance with graphene and graphitic carbon nanopaint-coated solar absorbers

Improving the efficiency of basin-type solar stills is crucial for ensuring reliable access to clean water in areas facing water scarcity. One effective way to increase water yield production is by applying various coatings to the solar still's absorber plate. Using nanocoatings on solar absorber plates increases solar radiation absorptivity and minimizes reflectivity, which helps improve water production. In this proposed work, Graphene nanoplatelets (GNPs)-based nano paint, graphitic carbon nanoparticles (GCNPs)-dispersed black paint, and conventional black paint were applied to the solar still's absorber plate. According to the study, the GNPs' nano paint resulted in a cumulative solar still productivity that was 48.23 % higher than the GCNPs-dispersed black paint and 10.28 % higher than the conventional black paint. It also revealed that the energy efficiency of solar stills with GCNPs and GNPs nano paint-coated absorbers was 56.96 % and 69.77 %, respectively, while the traditional black paint-coated absorber managed only 39.42 %. The calculated exergy efficiency of these three solar stills was 8.55 % for the conventional black paint, 13.93 % for the GCNPs, and 22.93 % for the GNPs nano paint-coated absorber. This proposed system also has an energy payback period of 1.79 years and contributes to achieving a carbon credit of $994.90 through the market. The cost of distilled water in this system is also 0.016$/L.

The impacts of DC/AC ratio, battery dispatch, and degradation on financial evaluation of bifacial PV+BESS systems

As the price of solar modules has decreased, oversizing PV system becomes a general practice. Without proper energy management, the oversized systems could lead to over-generation waste which cause a loss in revenue. Battery energy storage system (BESS) can be integrated to the PV system for utilizing the over-consumption energy and increasing the system’s financial benefits. This paper highlights the influence of technical and financial factors on the photovoltaic (PV) and PV with BESS design. To analyze the impacts of the factors on PV systems, thirty-six system configurations with a variety of geographic locations, tariff structures, billing methods, and PV system technology are simulated using System Advisor Model (SAM) as a tool with result validation from measurements on a real oversized residential grid-tied bifacial PV+BESS system. To study the financial criteria that affect the optimal system design, we conducted the sensitivity analysis of the DC/AC ratio, battery replacement threshold, and battery size to observe the optimal system design based on three financial outputs: levelized cost of energy (LCOE), net present value (NPV), and payback period. The findings show that the optimal DC/AC ratio for residential-scale PV systems lies between 1.1 - 1.3 and can go up to 1.6 with BESS. PV+BESS systems can reduce the payback period by 20% and boost NPV by 80% compared to the PV-only systems. The sensitivity study of the battery replacement shows that the battery can be degraded until 50% of its maximum capacity for the lowest LCOE. To achieve the optimal grid-tied PV system design, each economic parameter should be evaluated together.

Techno-Economic Feasibility Study of Earth Air Heat Exchangers for Gas Turbine Inlet Air Cooling

In response to pressing energy crises and environmental concerns, enhancing the performance of existing energy conversion systems, such as gas turbines, and tapping into renewable resources have become critical imperatives. Escalating ambient temperatures poses a notable challenge, hampering the efficiency of gas turbines. This study rigorously explores the feasibility of earth-to-air heat exchangers (EAHEs) as a pragmatic solution to cool gas turbine inlet air. The primary objective is an exhaustive techno-economic analysis evaluating the long-term operational viability of EAHE systems. Employing the Taguchi method, the study optimizes the system geometry and pipe arrangement, focusing on four key control factors: pipe diameter, spacing, length, and depth. The pivotal optimization criterion is the levelized cost of energy (LCOE), encompassing thermal performance and economic viability. The net present value (NPV) and Discounted Payback Period provide supplementary insights into the economic prospects. Integral to the study is a novel and intricate hybrid analytical-numerical model that simulates the long-term transient operation of EAHE. Findings from a detailed case study unveil an optimized scenario yielding an LCOE amounting to 0.071 $/kWh, accompanied by a substantial NPV of 4.5 million dollars.

Life cycle and techno-economic analyses of biofuels production via anaerobic digestion and amine scrubbing CO2 capture

The global energy landscape highlights the importance of the hydrogen economy, emphasizing its critical role in worldwide energy policies. This study explores a system designed for producing biomethanol and biomethane by integrating anaerobic digestion, biogas upgrading, and high-temperature electrolysis. The system builds on real-scale industrial data from an existing anaerobic digestion plant, which has been expanded to include biogas upgrading, an oxy-fuel gas turbine, a Solid Oxide Electrolysis Cell (SOEC), and a methanol production unit. Hydrogen, generated through electrolysis, synthesizes biomethanol by reacting with CO2. Additionally, the system produces biomethane through biogas upgrading. The system incorporates thermal energy integration with an oxy-fuel gas turbine. Life cycle assessment (LCA) results demonstrate the system’s environmental potential, achieved negative CO2 emissions of −0.0075 kgCO2eq/kgBiomass in case of photovoltaic panels and −0.0096 kgCO2eq/kgBiomass in case of wind turbines as electricity sources, attributed to efficient conversion of sewage sludge into valuable biofuels. Thermodynamic modeling in Aspen Plus shows an energy efficiency of 58.09 %, with outputs of 188 kg/h of biomethane and 269 kg/h of biomethanol. The techno-economic analysis reveals a payback period of 6.11 years and a levelized cost of biomethanol of 294.37 € per ton, indicating the system’s economic viability. The LCA further underscores the system’s sustainability, supporting its environmental benefits. This comprehensive analysis provides valuable insights into the viability and environmental impact of the proposed biofuel production system.

Exergy and thermoeconomic analysis of a novel polygeneration system based on gasification and power-to-x strategy

This study introduces a novel polygeneration system that integrates biomass gasification, anaerobic digestion, photovoltaic (PV) energy, and electrolysis to enhance system flexibility and efficiency. The system includes an allothermal gasification unit that processes lignocellulosic biomass sourced from a botanical garden. The gasifying agent, either steam or oxygen, is supplied by an alkaline electrolyzer, which operates under a Power-to-X strategy, utilizing surplus energy from a PV field. The resulting syngas and hydrogen are blended with biogas from an anaerobic digester, which treats municipal waste, to power a cogenerator. This cogenerator meets the electricity, heating, and cooling demands of a hospital, while the PV field powers the botanical garden. The systems components are modeled using various tools and integrated into the TRNSYS environment for dynamic simulation. An exergy analysis identifies the main sources of exergy destruction, while a thermo-economic analysis evaluates the energy, environmental, and economic impacts of a demonstration plant located in Bogotá’s Botanical Garden. Simulation results show that the system achieves an overall exergy efficiency of around 35 %, with a 96 % reduction in primary energy consumption compared to a reference system, avoiding nearly 6000 tons of CO2 emissions annually. From an economic perspective, the system is profitable, with a payback period of 3.02 years and a Net Present Value of $15.23 million, almost double the capital cost. The gasification unit's exergy efficiency is significantly higher when using oxygen (0.50) compared to steam (0.25), underscoring the importance of integrating electrolysis for improved biomass conversion. The alkaline electrolyzer operates efficiently within its optimal range, with an energy efficiency close to 0.70 and an exergy efficiency around 0.60, effectively utilizing 25 % of the total PV production.

The effectiveness of duty cycling technique on air conditioning system during break period for comfort, energy and cost savings: A real case study in health center

This paper investigates the potential of duty cycling techniques for air conditioning (AC) systems in producing energy and cost savings and the impact on the indoor thermal environment, air quality, and environmental sustainability. The real case study concentrated on energy consumption practice during the break period between 13:00 to 14:00 in a lobby area of a Health Center. Site data measurements of electrical input power, energy, indoor air temperature and humidity, and indoor carbon dioxide (CO2) concentration were conducted. Two zero-cost strategies were studied and results were compared to baseline conditions. In general, the results show that all strategies can meet the indoor thermal environment and air quality requirements, except room temperature for Strategy 2 which ranges on average between 26.71 to 26.82C. In addition to the instant payback period (0 years), the results also indicate that as compared to baseline condition, Strategies 1 and 2 led to annual energy and cost savings of around 759.2 kWh (USD 64.40) and 1250.6 kWh (USD 106.08), respectively. In terms of environmental sustainability, Strategies 1 and 2 can avoid environmental CO2 emissions by 444.13 and 731.60 kg of CO2 per year, respectively. Due to these reasons and if the sensitivity of occupant comfort to room temperature during the break period can be tolerated, it is proposed that Strategy 2 is the best option for the AC system operation during the break period. Considering other buildings also adopted the same strategy, this small action can lead to a high impact, not only on energy and cost savings but also on environmental sustainability in the future.

Utilization of waste hot air of medical oxygen plant in solar desalination unit employing jet impingement air heater for water production

ABSTRACT Many oxygen plants have been established specially during COVID-19 period and they are still serving for medical needs. The objective of the present work is to utilize solar and waste thermal energy of medical oxygen plants for water production. Humidification–dehumidification desalination (HDD) has been found suitable for this objective due to low temperature energy need during the process. The layout of an HDD unit has been presented to utilize waste heat, specially when solar energy is not much effective or absent. The system has been configured with a jet impingement solar air heater and a packed bed humidifier. A mathematical model has been developed and validated with the results of experiments. A comparative study of the proposed unit (HDD-O2) and a conventional unit has been performed in terms of yield and gained output ratio (GOR). The optimum flow rates of working fluids found in the range 0.03–0.04 kg/s and the temperature of air and water resulted in a continuous gain in yield. The average yield and GOR of the HDD-O2 unit were found to be 8.5 kg/d and 1.1 that could reach up to 11 kg/d and 1.4, respectively. The HDD-O2 unit provided yield at the cost of 0.04 $/kg with a payback period of 1.73 years. The findings of the present work indicated the suitability of the HDD-O2 plant for water production.

Sustainable energy transition: A steam system optimization case study from a Moroccan food industry

Industrial steam systems account for approximately 30 % of energy use in the manufacturing industry worldwide. In the context of energy transition, improving the energy efficiency of these systems is crucial, as it can significantly reduce energy losses, costs, and greenhouse gas (GHG) emissions. This study presents a comprehensive analysis of the steam system in a Moroccan agri-food plant, aiming to identify and quantify energy optimization opportunities. Initially, the Steam System Scoping Tool (SSST) benchmark revealed a score of 42.4 %, highlighting key areas for improvement. The study proceeded by diagnosing and modeling the baseline steam system, identifying major energy losses based on thermodynamic equations and Manufacturing Energy Assessment Software for Utility Reduction (MEASUR). Our study distinctively employs a systems-based approach, proposing eight energy-saving measures that holistically address all aspects of the steam system —generation, distribution, end-use, and recovery—rather than examining each component in isolation. These measures include optimizing boiler combustion, repairing insulation and leaks, reducing idle operations, and enhancing heat recovery through a feedwater economizer. Implementing these measures is projected to achieve annual energy savings of 5096 GJ, reduce CO2 emissions by 319 tons, and save $93,764, representing a 53 % reduction in the plant's thermal bill. This significant cost-saving potential should inspire optimism about the financial benefits of energy optimization, with payback periods ranging from immediate to a few months. This research marks a pioneering effort in Morocco's industrial sector, offering a replicable model that aligns with global sustainable development goals (SDGs) by reducing energy losses and enhancing production performance.

Socio‐economic impact of solar cooking technologies on community kitchens under different climate conditions: A review

AbstractResidential cooking with non‐renewable energy sources, such as firewood, charcoal, natural gas, participate in the emission of more than a gigaton of CO2 per year, which represents 2% of the global CO2 emissions. Additionally, toxic particles including sulfur dioxide, carbon monoxide, and mercury are released leading to elevated levels of indoor air pollution, and adversely affecting the health of the inhabitants. The residential sector's non‐renewable energy cooking devices also pose significant problems, consuming approximately 30%–40% of global energy usage, with over 80% dedicated to cooking applications. To mitigate the negative impacts of traditional cooking on health and the environment, various renewable energy‐based cooking technologies have been developed recently. The primary contributions of our paper are to: (a) present a comprehensive review of concentrated solar thermal cooking technologies, assessing their social, economic, and environmental impact across different climatic zones in developing countries like India; (b) classify and compare different solar cooking technologies, highlighting their advantages and limitations in various scenarios; (c) evaluate the energy efficiency of diverse solar cooking technologies; (d) analyze the impact of solar cookers on communities in developing countries; and (e) identify the challenges and future directions for solar cooker technologies, particularly in solar community kitchens. Our novel findings demonstrate that using solar cooking devices can reduce energy consumption by up to 56% in Indian schools. Moreover, the payback period ranges from 3 to 6 years, contingent on the technology's cost, climatic conditions, and available subsidies. Consequently, significant positive impacts on society, the economy, and the environment are observed when traditional cooking devices are replaced by solar cooking devices. This study provides a unique and thorough analysis, contributing to the growing body of knowledge on sustainable cooking solutions and their potential to transform energy consumption patterns in developing regions.

Techno-economic and environmental analysis of biogas-based hybrid renewable energy systems: A case study for a small-scale livestock farm

Biogas technology offers a significant benefit in enabling energy generation from distributed sources of biomass through its easy scalability. This study aimed to conduct the technical, economic, and environmental analysis of biogas-based hybrid renewable energy systems in a small-scale livestock farm located in the rural area of the Central Anatolia region in Türkiye. The HOMER software was used to analyze a total of five scenarios. These scenarios are hybrid combinations of a biogas generator, PV panels and wind turbines. The hybrid scenarios were evaluated by comparing them to each other and to the base scenario, which only has a grid connection. The optimal system has been determined to be the grid-connected Biogas/PV panel hybrid configuration, with an energy cost of 0.0688 $/kWh and a net present cost of $70,777. The optimal system has a renewable fraction of 89.9 % and a CO2 emissions mitigation potential of 13,066 kg/year compared to the base scenario. Furthermore, sensitivity analysis for various input parameters such as grid sellback rate, interest rate and load demand was performed to assess the impact of changes in these parameters on the system. Sensitivity analysis results show that increased grid sellback rates can significantly enhance financial metrics and reduce the payback period from 13.13 years to 6.63 years.

Exergo and enviro-economic analysis of thermal energy storage assisted finned solar still

The current investigation focuses on improving the performance of a single slope solar still integrated with Phase Change Material as energy storage media. The problem of low thermal conductivity of PCM which hinders the energy storage capability has been addressed by incorporating fins with different profiles into the energy storage unit. Initially, an experimental investigation was conducted and analyzed to assess the effective performance of a Conventional Single Slope Solar Still (CSS) using various water depth levels: 1–4 cm. The optimal basin water depth for testing solar still with energy storage material along with fins was identified as 2 cm. Subsequently, the CSS was subjected to performance enhancement investigation under three different conditions: Case 1 – Solar Still (SS) with PCM storage unit, Case 2 – SS with fins at the PCM storage unit, and Case 3 – SS with fins at the storage unit and a parallel plate attached to the other end of the fins. The experimental results demonstrated the production of fresh water and efficiency improvements are as follows 26.95%, 55.86%, 69.14% and 24.34%, 52.83%, 68.83% for cases I, II, and III, respectively. Further, it was observed that Case III exhibited a lower cost of water production and a shorter payback period compared to CSS. The enviro-economic analysis revealed that the net CO2 emissions (NCEM) and Carbon Credits Earned (CCE) for Case III were 15.60 tons and 312.07 USD respectively against 9.22 tons and 184.31 USD for CSS.