- 标题
- 摘要
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Effects of different greenhouse coverings on energy parameters of a photovoltaic–thermal solar system
摘要： The present study analyzed the power and heat supply of a small-scale greenhouse by a photovoltaic–thermal (PV/T) system while using three greenhouse coverings (glass, plastic and polycarbonate) and four water mass flow rates (0.016, 0.025, 0.033 kg/s and no-flow), with or without a solar tracker. The electrical efficiency results for PV (without mass flow) and PV/T (0.016, 0.025 and 0.033 kg/s) states indicated that the application of the PV/T system enhanced electrical efficiency by 21.5, 28.4 and 36.84% for the glass glazing, by 15.28, 25 and 34.79% for the plastic covering, and by 19.82, 26.67 and 40.25% for the polycarbonate covering, compared to the PV state. The highest overall efficiency was at 0.033 kg/s with 59.9% (glass), 54.56% (plastic) and 47.58% (polycarbonate), and the lowest overall efficiency was at 0.016 kg/s with 41.75% (glass), 32.94% (plastic) and 31.22% (polycarbonate). In general, due to the electrical and thermal energy requirements of greenhouses, it can be said that, in addition to producing electricity by PV/T systems, their significant thermal energy production compared to PV panels can also promote the use of such systems in the future.
关键词： Photovoltaic/thermal,Different greenhouse coverings,Electrical efficiency,Thermal efficiency
更新于2025-09-11 14:15:04
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Life cycle analysis of a building integrated photovoltaic system operating in Bogotá, Colombia
摘要： In this study, the environmental behavior was characterized for a 840 Wp building-integrated photovoltaic (BIPV) system installed in the Department of Physics of the Faculty of Sciences at the National University of Colombia, Bogota campus. The methodology focused on the application of the international technical standards for Life Cycle Analysis (LCA) from cradle to grave based on the NTC ISO 14040 and NTC ISO 1404 standards, which regulate the methodological procedure. This article is based on comparing the potential of environmental impacts of five power generation scenarios, taking as reference the installation of the photovoltaic system (PV) at the University. During the analysis it was possible to determine that energy generation with coal has a greatest environmental impact compared with photovoltaics: 84% and 6% respectively. This represents 1138.8 gCO2eq/kWh for coal, compared to 35 gCO2eq/kWh for the PV system.
关键词： Solar energy,Solar cells,Greenhouse emissions,Photovoltaic systems,Life cycle analysis
更新于2025-09-11 14:15:04
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Solar light distribution inside a greenhouse with the roof area entirely covered with photovoltaic panels
摘要： Most photovoltaic (PV) greenhouses in Europe have maximised the energy production without considering the requirements of the crops, by applying PV panels on most part of the roof area. The aim of this work is to calculate the solar light distribution in a photovoltaic (PV) greenhouse where the entire roof area is covered with PV panels (100% cover ratio). The calculation of the incident global was estimated with clear sky conditions on several observation points located inside the greenhouse at 1.5 m from the ground level. The validation of the simulated data was conducted through measurements inside a PV greenhouse complex located in Florinas, Italy (40°38’38”N; 8°39’31”E), composed by 24 single-span greenhouse modules of 837 m2 each and total area of 2.2 ha. The roof area of each module was completely covered with a monocrystalline PV array with slope of 20° and a rated power of 22 kWp. The results were shown through a map of light distribution on the greenhouse area, which highlighted the most penalised zones and the percentage of available global radiation, compared to the same greenhouse without PV array. Good agreement was shown by the simulated data, compared to measurements (mean R2=0.78). The global radiation on the greenhouse area was 33% on yearly basis, compared to the potential value with no PV panels on the roof. The zones close to the gable walls and the south side wall suffered less shading compared to the central portion of the greenhouse area. The map of cumulated light distribution can support the growers to increase the agronomic sustainability of the PV greenhouse, since it will allow in perspective the identification of species and crop management practices for a profitable cultivation.
关键词： agricultural sustainability,PV greenhouse,crop,model,solar radiation,energy
更新于2025-09-11 14:15:04
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Regional economic and environmental impacts of renewable energy developments: Solar PV in the Aachen Region
摘要： The energy transition is a challenge that affects regions on various scales. This paper presents the economic chances of deploying the renewable energy technology solar photovoltaic in a German region. Total regional economic effects of 280 PV plants, installed in 2014 with a cumulative capacity of 3.7 MW, lead to a regional value added of approximately €3.8 million (€1019/kW installed, €57/MWh electricity generated) and employment effects of 42 full-time person years (11 person years/MW installed), occurring from 2014 to 2034. The avoided greenhouse gas emissions of these plants are 2365 tons CO2 equivalents per year (0.7 kgCO2-eq/kWh generated) and the avoided air pollution is 0.97 tSO2 per year, 1.48 tNOx per year, and 0.07 t NMVOCs per year in 2014. The total economic effects of regional value added, avoided CO2 emissions, and avoided air pollution per year in 2014 range from €0.8 million - €1 million or (€208–€277 per kW installed, €231–€307 per MWh electricity generated).
关键词： Economic impact assessment,Regional economic impact assessment,Greenhouse gas emissions,Renewable energies,Solar PV,Air pollutants
更新于2025-09-10 09:29:36
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Managing Global Warming || Solar energy
摘要： I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.
关键词： photovoltaic,solar thermal energy,greenhouse gas emissions,renewable energy,solar energy
更新于2025-09-10 09:29:36
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Metal Oxides in Energy Technologies || Solar-driven fuel production by metal-oxide thermochemical cycles
摘要： Nowadays, the need to reduce anthropogenic emissions of greenhouse gases due to combustion of fossil fuels causing the increase of global average surface air temperatures and the need to meet an expanding global energy demand are the most pressing challenges faced by mankind [1, 2]. Solar energy, which is clean, renewable, plentiful, and distributed, offers an intelligent solution to both challenges [1]. One promising approach to harvest and store solar energy is the production of synthetic fuels, that is, solar-driven fuel, via high-temperature thermochemical processes. Solar-driven fuel has significant advantages for long-time storage and/or long-distance transportation of energy [3, 4]. It not only is an appealing supplement or alternative to fossil fuels, but also has the potential to alleviate concerns environment, security, and price volatility, which are associated with the production, transportation, and consumption of fossil fuels, especially imported petroleum [5].
关键词： Solar-driven fuel production,energy demand,metal-oxide thermochemical cycles,solar energy,synthetic fuels,greenhouse gases
更新于2025-09-10 09:29:36
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Fourier transform spectrometer measurements of column CO<sub>2</sub> at Sodankyl?, Finland
摘要： Fourier transform spectrometer (FTS) observations at Sodankyl?, Finland (67.4? N, 26.6? E) have been performed since early 2009. The FTS instrument is participating in the Total Carbon Column Observing Network (TCCON) and has been optimized to measure abundances of the key greenhouse gases in the atmosphere. Sodankyl? is the only TCCON station in the Fennoscandia region. Here we report the measured CO2 time series over a 7-year period (2009–2015) and provide a description of the FTS system and data processing at Sodankyl?. We ?nd the lowest monthly column CO2 values in August and the highest monthly values during the February–May season. Inter-annual variability is the highest in the June–September period, which correlates with the growing season. During the time period of FTS measurements from 2009 to 2015, we have observed a 2.2 ± 0.2 ppm increase per year in column CO2. The monthly mean column CO2 values have exceeded 400 ppm level for the ?rst time in February 2014.
关键词： CO2,Sodankyl?,TCCON,Fourier transform spectrometer,greenhouse gases
更新于2025-09-09 09:28:46
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Predicting the water production of a solar seawater greenhouse desalination unit using multi-layer perceptron model
摘要： A solar seawater greenhouse is a type of desalination plant that uses solar energy and seawater to humidify the interior of the greenhouse and produce fresh water from the humid air (humidification-dehumidification process). The produced water is used both for irrigating agricultural crops and for drinking. Many parameters affect the performance of seawater greenhouses. The present study employed an artificial neural network to examine the effective parameters of the greenhouse on the fresh water production such as width, length, the height of the front evaporator, and roof transparency. A suitable structure was obtained for the multi-layer perceptron (MLP) method and the mathematical statistics % AARE, RMSE, and R2, were used to evaluate network performance. The method showed good agreement with the experimental data. Using the optimized created network, the effect of each parameter on the produced fresh water was assessed. Finally, a 125 m wide and 200 m long of greenhouse with a 4 m height of front evaporator and roof transparency of 0.6 that produced 161.6 m3/day of fresh water was introduced as the optimal seawater greenhouse.
关键词： Solar seawater greenhouse,Desalination,Humidification-dehumidification process,Multi-layer perceptron
更新于2025-09-09 09:28:46
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Accurate mobile remote sensing of XCO<sub>2</sub> and XCH<sub>4</sub> latitudinal transects from aboard a research vessel
摘要： A portable Fourier transform spectrometer (FTS), model EM27/SUN, was deployed onboard the research vessel Polarstern to measure the column-average dry air mole fractions of carbon dioxide (XCO2) and methane (XCH4) by means of direct sunlight absorption spectrometry. We report on technical developments as well as data calibration and reduction measures required to achieve the targeted accuracy of fractions of a percent in retrieved XCO2 and XCH4 while operating the instrument under field conditions onboard the moving platform during a 6-week cruise on the Atlantic from Cape Town (South Africa, 34? S, 18? E; 5 March 2014) to Bremerhaven (Germany, 54? N, 19? E; 14 April 2014). We demonstrate that our solar tracker typically achieved a tracking precision of better than 0.05? toward the center of the sun throughout the ship cruise which facilitates accurate XCO2 and XCH4 retrievals even under harsh ambient wind conditions. We define several quality filters that screen spectra, e.g., when the field of view was partially obstructed by ship structures or when the lines-of-sight crossed the ship exhaust plume. The measurements in clean oceanic air, can be used to characterize a spurious air-mass dependency. After the campaign, deployment of the spectrometer alongside the TCCON (Total Carbon Column Observing Network) instrument at Karlsruhe, Germany, allowed for determining a calibration factor that makes the entire campaign record traceable to World Meteorological Organization (WMO) standards. Comparisons to observations of the GOSAT satellite and concentration fields modeled by the European Centre for Medium-Range Weather Forecasts (ECMWF) Copernicus Atmosphere Monitoring Service (CAMS) demonstrate that the observational setup is well suited to provide validation opportunities above the ocean and along interhemispheric transects.
关键词： solar tracker,EM27/SUN,atmospheric greenhouse gases,XCO2,XCH4,Fourier transform spectrometer,shipborne measurements
更新于2025-09-04 15:30:14
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Calibration and instrumental line shape characterization of a set of portable FTIR spectrometers for detecting greenhouse gas emissions
摘要： A comprehensive calibration procedure for mobile, low-resolution, solar-absorption FTIR spectrometers, used for greenhouse gases observations, is developed. These instruments commend themselves for campaign use and deployment at remote sites. The instrumental line shape (ILS) of each spectrometer has been thoroughly characterized by analyzing the shape of H2O signatures in open path spectra. A setup for the external source is suggested and the invariance of derived ILS parameters with regard to chosen path length is demonstrated. The instrumental line shape characteristics of all spectrometers were found to be close to nominal. Side-by-side solar observations before and after a campaign, which involved shipping of all spectrometers to a selected target site and back, are applied for verifying the temporal invariability of instrumental characteristics and for deriving intercalibration factors for XCO2 and XCH4, which take into account residual differences of instrumental characteristics. An excellent level of agreement and stability was found between the different spectrometers: the uncorrected biases in XCO2 and XCH4 are smaller than 0.01 and 0.15 %, respectively, and the drifts are smaller than 0.005 and 0.035 %. As an additional sensitive demonstration of the instrumental performance we show the excellent agreement of ground pressure values obtained from the total column measurements of O2 and barometric records. We find a calibration factor of 0.9700 for the spectroscopic measurements in comparison to the barometric records and a very small scatter between the individual spectrometers (0.02 %). As a final calibration step, using a co-located TCCON (Total Carbon Column Observation Network) spectrometer as a reference, a common scaling factor has been derived for the XCO2 and XCH4 products, which ensures that the records are traceable to the WMO in situ scale.
关键词： calibration,XCO2,XCH4,FTIR spectrometers,instrumental line shape,greenhouse gas emissions
更新于2025-09-04 15:30:14