Life Cycle Conversion Efficiency Research Articles

Combined effects of composite thermal energy storage and magnetic field to enhance productivity in solar desalination

The conventional solar still is limited to a daily yield of approximately 2–3.5 kg/m2/day. To increase the yield, this study investigates experimentally the combined effects of latent and sensible energy storage together with magnetization. Paraffin and novel high-thermal conductivity nanomaterial (graphite plate) were used as latent and sensible heat storage materials, respectively. There was an overall increase of 62% and 235% in the daytime and night-time yield, respectively, giving a total yield of 5.5 kg/m2/day compared to 3.4 kg/m2/day for a conventional still. Enviro-economic parameters like emissions, CO2 mitigation and carbon credit (CC) earned were also investigated. Energy matrices analysis and water quality checks were performed to estimate the energy-payback time, life cycle conversion efficiency (LCCE) and purity of desalinated water. The cost per liter of freshwater was found to be 3.7% cheaper than for a conventional still and 69% cheaper than bottled water in India. Over a 30 year period, 40.3 Tonnes of CO2 will be mitigated contributing a CC and LCCE of $402 and 0.52, respectively. The proposed modified still is recommended as a substitute for conventional stills and stills with simple energy storage.

Material conscious energy matrix and enviro-economic analysis of passive ETC solar still

The current scenario faces potable water scarcity all over the world and in that perspective; the solar distillation system plays an important role. In accordance with that system should be economic, self-sustainable and environment-friendly. To carry these words, this paper represents the system behavior based on energy payback time, life cycle conversion efficiency, CO2, SO2, NO emissions, carbon mitigations, etc. This work shows a performance analysis of passive evacuated tubular collector solar still based on energy matrices and enviro-economic parameters. Single slope solar still with ETC shows considerable embodied energy (1138.52 kWh) and yields up to 3.8 l/m2/day with 77.2 tons of carbon mitigation for 30 years of life. The carbon credit earned by the system was $771.23. Also, the system has lower energy payback time and better life cycle conversion efficiency i.e. 0.68 yrs and 0.34 respectively.

A study of life cycle conversion efficiency and CO2 role in the pyramid shape solar stills – Comparative analysis

The comparative analysis of the Conventional Pyramid Still (CPS) with the Shaded Pyramid Still (SPS) is fabricated and experimented in estimating the carbon dioxide (CO2) emission and embodied energy. The single basin square pyramid shape solar still is used for experiments. The daily production of distilled water was measured from both the still for the analysis. The cumulative yield from the CPS is 2.6 kg/day, and SPS is 1.7 kg/day. The outcome of the investigation shows that the CO2 emission and embodied energy was decreased in CPS as compared with SPS and energy production factor, Life Cycle Conversion Efficiency (LCCE), CO2 mitigation, and Carbon credit was increased in the CPS compared with the SPS. The LCCE for CPS was 30.39%, and for SPS was 19.98% at 30 years life. Similarly, the CO2 mitigation for CPS was 20.07 tons and for SPS was 13.19 tons. The distilled water can be sold at Rs. 23.28 per kg for CPS and Rs. 22.67 per kg for SPS and the payback year of both the still were 0.52 and 0.82 years, respectively concerning carbon credit for the expected life year of still is 30 years.

Operational Performance and Degradation Influenced Life Cycle Environmental–Economic Metrics of mc-Si, a-Si and HIT Photovoltaic Arrays in Hot Semi-arid Climates

Life cycle metrics evolution specific to the climate zone of photovoltaic (PV) operation would give detailed insights on the environmental and economic performance. At present, vast literature is available on the PV life cycle metrics where only the output energies ignoring the degradation rate (DR) influence. In this study, the environ-economic analysis of three PV technologies, namely, multi-crystalline silicon (mc-Si), amorphous silicon (a-Si) and hetero-junction with an intrinsic thin layer (HIT) have been carried out in identical environmental conditions. The energy performance parameters and the DR rate of three PV technologies are evaluated based on the monitored real time data from the installation site in hot semi-arid climates. The assessment demonstrates that the HIT PV module technology exhibits more suitable results compared to mc-Si and a-Si PV systems in hot semi-arid climatic conditions of India. Moreover, energy metrices which includes energy payback time (EPBT), energy production factor (EPF) and life cycle conversion efficiency (LCCE) of the HIT technologies are found to be 1.0, 24.93 and 0.15 years, respectively. HIT PV system has higher potential to mitigate the CO2 and carbon credit earned compared to mc-Si and a-Si PV system under hot semi-arid climate. However, the annualized uniform cost (UAC) for mc-Si (3.60 Rs/kWh) and a-Si (3.40 Rs/kWh) are more admissible in relation to the HIT (6.63 Rs/kWh) PV module type. We conclude that the approach of considering DR influenced life cycle metrics over the traditional approach can support to identify suitable locations for specific PV technology.

Viability assessment of solar distillation for desalination in coastal locations of Indian sub-continent – Thermodynamic, condensate quality and enviro-economic aspects

In the current investigation, viable solar desalting sites in coastal India are identified by detailed thermodynamic and enviro-economic analyses. Mathematical model developed for thermodynamic performance assessment is validated using experiments conducted in inclined solar distillation unit under the climatic condition of Chennai (13.08°N, 80.27°E). Distillation unit produced high quality condensate even from highly saline (40,600 to 60,656 mg/L salinity) feed water. Availability analysis indicated the magnitude of improvement potential, availability destruction, losses and ways for further improvement. Maximum condensate yield, energy and availability efficiency of distillation unit is around 7.09 L/d, 53.45% and 5.39%, respectively for Nellore (one of the east coast locations). Condensate production cost of 18.16 to 32.78 USD/kL and desired availability output of 1.80 to 3.38 kWh/USD invested are observed for the distillation unit at 5.0% interest rate. Maximum yearly average life cycle conversion efficiency, net carbon-dioxide, sulphur-dioxide and nitrous oxide emission alleviated by the unit is around 39.19%, 25.83 tons, 185.73 kg and 75.86 kg, respectively. Viability assessment indicated positive signs for deployment of solar distillation units in 14 locations of coastal India. The proposed solar distillation unit requires lower evaporation area compared to other passive solar distillation units installed in India for the same production capacity.

Effect of flow of fluid mass per unit time on life cycle conversion efficiency of single slope solar desalination unit coupled with N identical evacuated tubular collectors

Present work shows the flow effect of water mass per unit time (MFR) on the life cycle conversion efficiency (LCCE) of a single slope solar desalination unit (SSSDU) coupled with N identical evacuated tubular collectors (N-ETC). The analysis is observed for a typical days of May and December for the atmospheric situation of New Delhi with the help of analytical program fed in MATLAB. The input data required for the numerical computations have been taken from IMD, Pune, India. The average value of annual energy output has been computed based on the enegy outputs of summer and winter seasons followed by the evaluation of LCCE for the system. It has been concluded that the value of LCCE diminishes with the raise in the value of fluid flow mass/ unit time and values of LCCE becomes almost constant beyond 0.044 kg/s at given values of water depth and number of collectors. It has also been observed that the value of LCCE has similar trends at other number of collectors.

Effect of number of collectors (N) on life cycle conversion efficiency of single slope solar desalination unit coupled with N identical partly covered compound parabolic concentrator collectors

In this paper, the effect of number of collectors on the life cycle conversion efficiency (LCCE) of a single slope solar desalination unit (SSSDU) coupled with N alike partly covered photovoltaic thermal compound parabolic concentrator collectors (PVTCPCs) has been communicated. The analysis has been carried out for an archetypal day of July and December for the atmospheric situation of New Delhi with the help of analytical program fed in MATLAB. The average value of energy output for type a weather condition has been taken to find the annual energy output. The input data required for the numerical computations have been taken from IMD, Pune, India. It has been observed that the value of LCCE increases with the raise in the value of number of collectors.

Performance Analysis of Grid-Connected 10.6 kW (Commercial) Solar PV Power Generation System

In this paper design aspects and performance of a rooftop grid-connected solar photovoltaic power plant (RTGCSPVPP) has been studied. The RTGCSPVPP is installed at Gauri Maternity Home Ramkrishna Puram Kota Rajasthan, India for supplying the energy to whole hospital building. It was observed under a certain period of time during May 2017. Power output and other parameters such as economic parameters which affect the feasibility of a PV plant as payback period, net present value, life cycle conversion efficiency, environmental related parameters as CO2 mitigation and earned carbon credits were calculated. Total energy demand and monthly energy consumption of previous one year of the site was assessed and analyzed for base load calculation and design. The outcome shows the financial viability and possible reduction of burden on conventional energy sources. The grid-connectivity of PV plant made through a net-metering system which supplied energy to the grid when power generation is more than its demand and receives the energy during low power generation.

Performance analysis and energy metrics of grid-connected photovoltaic systems

The performance of two co-located grid-connected photovoltaic (PV) systems comprising polycrystalline silicon (p-Si) and copper indium selenium (CIS) arrays are analyzed in this work. The measured and simulated performances are compared with an objective to study the suitability of the technology in the real hot and humid climatic conditions of Tamil Nadu, Southern India. The parameters used for the performance evaluation are array yield, final yield, PV efficiency, performance ratio and capacity utilization factor. The year-round performances of both the photovoltaic (PV) systems are predicted by PVsyst software using measured weather data at the site and compared with that of the actual measured results. The normalized measured annual energy delivered to the grid is 1536.9 kWh and 1698.4 kWh for p-Si and CIS PV systems respectively. The yearly average performance ratio is 78.48% for p-Si and 86.73% for CIS while the capacity utilization factor varies from 17.99% (for p-Si) to 19.57% (for CIS) respectively. Also, high capture losses are observed in the p-Si PV plant than that in the CIS PV plant. The performance indices of the PV systems are compared with that of the similar capacity PV systems situated at other locations. Further, embodied energy, energy payback time (EPBT), energy production factor (EPF), and life cycle conversion efficiency (LCCE) of the PV systems have also been estimated. The energy yield of CIS array is found to be 7.61% more in comparison to p-Si array round the year favoring its suitability for potentially, sites with a similar climate.

Significant factors for enhancing the life cycle assessment of photovoltaic thermal air collector

Due to the rapid industrialization and development across the entire globe, there is the increasing demand for energy. However, the energy sources from fossil fuels are not abundant in every part of the world. India has to import fuel from other parts of the world which consumes a major portion of Government funds. So, currently improving solar energy technologies efficiency is one of the most promising researches in India. This study is mostly about life cycle assessment (LCA) of photovoltaic thermal (PVT) air collectors. All the important parameters like Energy payback time (EPBT), Energy production factors (EPF), Lifecycle conversion efficiency (LCCE), Embodied energy, Life cycle cost assessment (LCCA) and carbon emissions are investigated in this study as well. The role of these parameters in the LCA study is depicted in this study since LCA greatly impacts the effectiveness and cost of PVT air collector. Results revealed that the EPBT, GPBT, EPF, and LCCE are in the range of 0.8 to 14 years, 1 to 4 years, 0.4 to 22, and 0.10 to 2.86.

Energy matrices, exergoeconomic and enviroeconomic analysis of modified multi–wick basin type double slope solar still

The present study is devoted to developing a thermal model of modified multi–wick basin type double slope solar still (MMWBDSSS). Analytical expressions of temperatures of water, wick, walls, and glass covers, distillate yield and instantaneous efficiency have been derived. The experimental validation of thermal model has been carried out and a fair agreement has been detected between theoretical results and experimental observations. On the basis of annual energy and exergy, the energy matrices, namely, the energy payback time (EPBT); life cycle conversion efficiency (LCCE); energy production factor (EPF), enviroeconomic and exergoeconomic analysis has also been evaluated for the solar still with jute and black cotton wicks under the climatic conditions of Allahabad, Uttar Pradesh (U.P.), India. The CO2 emission mitigated per annum has been found to be 7.82 and 8.69 tons on energy basis; and 0.155 and 0.198 tons on exergy basis with jute and black cotton wicks at 1 cm water depth, respectively. The exergoeconomic parameter has been found to be 0.0623 kWh/Rs. and 0.0791 kWh/Rs. for the solar still with jute and black cotton wicks at 1 cm water depth, respectively for 4% interest rate and 50 years life span of the system.

Energy metrics analysis of N identical evacuated tubular collectors integrated single slope solar still

In this paper, theoretical analysis of single slope solar still (SS) integrated with N identical evacuated tubular collectors (N-ETC-SS) has been performed on the basis of energy metrics. The proposed system has been analyzed considering four categories of weather condition for each month of year for New Delhi climatic condition. Results of the proposed N-ETC-SS has been compared with SS integrated with N identical photovoltaic thermal (PVT) flat plate collectors (N-PVT-FPC-SS), SS integrated with N identical PVT compound parabolic concentrator collectors (N-PVT-CPC-SS) and conventional SS (CSS). It has been concluded that N-ETC-SS performs best on the basis of exergy based energy metrics followed by N-PVT-FPC-SS, CSS and N-PVT-CPC-SS. The value of exergy based energy payback time is lower by 40.38%, 102.78% and 166.58%; energy production factor is higher by 28.57%, 50.79% and 61.90% and life cycle conversion efficiency is higher by 44.83%, 65.52% and 75.86% for the proposed N-ETC-SS than N-PVT-FPC-SS, CSS and N-PVT-CPC-SS respectively.

Energy metrics analysis of N identical evacuated tubular collectors integrated double slope solar still

This paper deals with the theoretical analysis of double slope solar still (DS) integrated with N identical evacuated tubular collectors (N-ETC-DS) on the basis of energy metrics. The analysis has been done considering four types of weather condition for each month of year for New Delhi climatic condition. Results of the proposed N-ETC-DS has been compared with DS integrated with N identical photovoltaic thermal (PVT) flat plate collectors (N-PVT-FPC-DS), DS integrated with N identical PVT compound parabolic concentrator collectors (N-PVT-CPC-DS) and conventional DS (CDS). It has been concluded that N-ETC-DS performs best on the basis of exergy based energy payback time, energy production factor and life cycle conversion efficiency followed by N-PVT-FPC-DS, CDS and N-PVT-CPC-DS.

Improving the performance of single slope solar still by including N identical PVT collectors

This paper communicates the improvement in performance of single slope solar still (SS) by including N identical partially covered photovoltaic thermal (PVT) collectors. Three models have been considered namely, SS included with N identical partially covered PVT flat plate collectors (N-PVT-FPC-SS); SS included with N identical partially covered PVT compound parabolic concentrator collectors (N-PVT-CPC-SS) and conventional SS (CSS). In this work, yearly production of potable water, energy, exergy, energy metrics, cost of distillate output and cogeneration efficiency have been computed for the proposed N-PVT-FPC-SS at 0.14 m water depth under optimized condition for New Delhi, India. Results obtained have been compared with results reported by researchers previously and it has been concluded that exergy based energy payback time is lower by 89.90% and 44.45%; energy production factor is higher by 46.67% and 31.11%; life cycle conversion efficiency is higher by 56.25% and 37.50% and production cost of potable water is lower by 27.05% and 3.20% for the proposed N-PVT-FPC-SS than N-PVT-CPC-SS and CSS respectively. The proposed system can produce potable water on commercial scale and at the same time, it can meet DC electrical power need.

Life cycle assessment of the 3.2 kW cadmium telluride (CdTe) photovoltaic system in composite climate of India

Life cycle assessment for new emerging photovoltaic (PV) technology is an important tool to establish a PV system in field condition. In this paper, life cycle assessment of the 3.2 kW cadmium telluride (CdTe) PV system has been carried out on the basis of actual field performance data in a composite climate of India. Further, analysis has been performed on the basis of the energy metrics, life cycle assessment, per unit cost of electricity and carbon credit earned. The analysis of the PV system has been performed under the same environmental conditions likely solar irradiation, ambient temperature and wind speed, etc. Energy payback time (EPBT), energy production factor (EPF) and life cycle conversion efficiency (LCCE) of the PV system has been found to be 3.60 years, 0.27 and 0.0018 respectively. The unit cost of electricity of the PV system has been calculated as 9.85 INR/kW h for 5% interest rate and 30 years life span.

Unit cost analysis for Sodha Bers Complex (SBC): An energy efficient building

This paper presents performance evaluation of an energy efficient building named Sodha Bers Complex (SBC) for composite climate of India. SBC is a four story energy efficient building built at Varanasi (U.P.), India. Most of the cooling concepts like orientation, modified Trombe wall, earth shelter, cross ventilation, day lighting, wind tower, wind channel etc. have been incorporated in the design of SBC. The total embodied energy, CO₂ emission, annual energy saving of SBC has been evaluated. Further, energy matrices namely energy payback time (EPBT), energy production factor (EPF) and life cycle conversion efficiency (LCCE) based on an overall annual thermal energy have been evaluated. It has been found that the SBC is most economical from thermal energy point of view due to low grade thermal energy and carbon credit earned. Unit cost has been evaluated for two cases having different interest rate, salvage value and life of SBC building and found to be minimum for 5% of interest rate, 30% salvage value and 300years of life that is 2.52▪/kWh (0.039 $/kWh) and 2.22▪/kWh (0.034 $/kWh).

Energy Matrices of Building Integrated Photovoltaic Thermal Systems: Case Study

In this paper, an attempt has been made to study and analyze the integration of residential buildings with photovoltaic (PV) systems. PV panels can be integrated with buildings in various ways (façades, double skin façades, sunshades, rooftops, skylights, etc.), which not only helps in the generation of electricity but also produces thermal heat and daylight. Further, it adds to the aesthetic appeal of the building. More than one-third of the global energy requirement is dedicated to the building sector. About 23% of the total electricity demand accounts for the residential buildings. Integration of a PV system is necessary because it replaces the conventional building materials and at the same time acts as an energy generator to make the building self-sustainable. This reduces the building’s energy demand on the conventional grid and the overall emission of greenhouse gases. It has been found that integration of a semitransparent PV module integrated with the roof at Sodha Bers Complex (SBC) for composite climate at Varanasi, India, provided electrical energy, thermal energy (space heating and domestic hot water heating), and day lighting. The energy payback time (EPBT), energy production factor (EPF), and lifecycle conversion efficiency (LCCE) for ΔT = 8°C and average daily solar radiation = 450 W/m2 was obtained as 15.32 years, 19.58 years (for 300 years), and 0.47 years (for 300 years), respectively.

Energy matrices of U-shaped evacuated tubular collector (ETC) integrated with compound parabolic concentrator (CPC)

This paper deals with the detailed thermal modeling of U-shaped evacuated tubular collector (ETC) integrated with compound parabolic concentrator (CPC). Such type of system is very useful in the preheating process for very high temperature industrial applications. The theoretical model have also been experimentally validated. The energy matrices like Energy pay back time (EPBT), Energy production factor (EPF) and Life cycle conversion efficiency (LCCE) for evacuated tubular collectors connected in series without and with concentrator have been evaluated and compared in this paper. For six number of collectors connected in series, the maximum difference water temperature between inlet and outlet in ETC-CPC combination is found to be 24°C, whereas it is about 17°C in ETC without CPC. A good agreement between theoretical and experimental results has been observed. The annual thermal energy gain is found to be 1461.63kWh and 1859.66kWh for ETC and ETC-CPC system, respectively. The annual exergy gain is found to be 137.5kWh and 165.9kWh for ETC and ETC-CPC system, respectively. EPBT is increased by 6.2% and 11.6% and EPF is decreased by 5.7% and 25% on energy and exergy basis respectively for 20years life of the system when CPC is integrated with ETC.

Energy matrices, enviroeconomic and exergoeconomic analysis of passive double slope solar still with water based nanofluids

Nanofluids are the new generation of ultrafast heat transfer fluids due to their exceptional thermo-physical and optical properties and attracted attention of the researchers worldwide in recent times. Worldwide, research is underway to utilize the advances of nanotechnology for potable water production. In the present communication, the energy matrices, enviroeconomic analysis, and exergoeconomic analysis of passive double slope solar still (DSSS) has been carried out incorporating Al2O3, TiO2 and CuO-water based nanofluids. Significant enhancement in the annual productivity (Al2O3 19.10%; TiO2 10.38%; and CuO 5.25%), energy (Al2O3 26.76%; TiO2 19.36%; and CuO 12.96%), and exergy (Al2O3 37.77%; TiO2 25.55%; and CuO 11.99%) of passive DSSS system with nanofluids has been observed in comparison to the still with basefluid (water) only. On the basis of energy and exergy, the energy payback time (EPBT), energy production factor (EPF), life cycle conversion efficiency (LCCE), environmental cost and exergoeconomic parameter has been estimated for different interest rates (i=4%,8%,and10%) and life span (maximum 50years) of the passive DSSS loaded with proposed three different water based nanofluids.

Enhancement in energy metrics of double slope solar still by incorporating N identical PVT collectors

In this paper, double slope solar still has been analyzed by incorporating N identical partially covered photovoltaic thermal (PVT) collectors under optimized condition to assess the enhancement in energy metrics. Number of collectors, mass flow rate and water depth of N identical partially covered PVT flat plate collector (N-PVT-FPC-DS) have been optimized for climatic condition of New Delhi. Subsequently, annual distillate output, energy, exergy, energy metrics, cogeneration efficiency and cost of distillate output have been computed for the proposed N-PVT-FPC-DS at 0.14m water depth. Results obtained have been compared with results reported by previous researchers and it has been concluded that the proposed N-PVT-FPC-DS performs better than double slope solar still incorporated with N identical PVT compound parabolic concentrator collectors (N-PVT-CPC-DS) and conventional double slope solar still (CDSSS) on the basis of energy metrics and cost of distillate output. The exergy based energy payback time is lower by 74.66% and 62.62%; energy production factor is higher by 43.30% and 38.14%; life cycle conversion efficiency is higher by 48.57% and 48.57% and cost of distillate output is lower by 35.37% and 4.88% for the proposed N-PVT-FPC-DS than N-PVT-CPC-DS and CDSSS respectively.