Global solar radiation time series forecasting using different architectures of the multilayer perceptron modelPeñalva, J J; Lozano, D A; Murillo, J C; Ortega, F M
doi: 10.1088/1742-6596/2180/1/012017pmid: N/A
In this work, the multilayer perceptron model was used to forecast the time series of global solar radiation for a near future about a week. Different architectures of this model were built through varying its different hyperparameters such as optimizers, activation functions, number of neurons and neuron dropout in which their performance was evaluated using error metrics. It was found that the architectures (60, SGD, Sigmoid), (10, Adam, Relu) and (60, SGD, Sigmoid) presented an R2 around 0.877, 0.873 and 0.872, respectively. The architecture with neuron dropout (150, SGD, Sigmoid, 0.2) presented a higher performance among all the architectures evaluated and its R2 value was 0.884. Architectures with higher performance are used to predict future values of solar radiation.
Estimation of cycling aging of lithium-ion batteries for photovoltaic applicationsNakama, V; Lafoz, M; Nájera, J; Sal y Rosas, D
doi: 10.1088/1742-6596/2180/1/012011pmid: N/A
The installation of photovoltaic microgrids to meet energy needs has had a significant increase in recent years. Likewise, the use of lithium batteries to improve the performance of the microgrid is an issue that is being studied. In this sense, it is important to know the electrical response of the lithium battery under such environment and its degradation. In this sense, this paper presents a methodology developed for the mathematical modelling of the electrical behaviour of a lithium battery. This methodology has been developed from the integration of three mathematical models: dynamic model, thermal model and aging model. During its operation, the lithium battery will be subjected to constant charging and discharging processes (dynamic model), as well as to thermal stress, because of the combined effect of the current flow and the ambient temperature (thermal model), which will generate a lithium battery capacity loss (aging model). For the analysis, real data on photovoltaic production, residential consumption profile, ambient temperature and 48V 100Ah LFP battery datasheet have been used. The developed methodology allows estimating the aging of a lithium battery in real time.
Average photon energy assessment based on modelled spectra from the National Solar Radiation Database for Lima, PeruSevillano-Bendezú, M A; Conde, L A; de la Casa, J; Töfflinger, J A
doi: 10.1088/1742-6596/2180/1/012018pmid: N/A
The photovoltaic performance under operating outdoor conditions is affected by the variability of the solar spectrum. The spectral distribution is quantifiable using the average photon energy (APE). In the present study, we characterize the spectral distribution in a low-latitude location such as Lima - Peru through a decade of simulated solar spectra obtained on demand from the National Solar Radiation Database and taking as a reference one year of ground-based experimental data following the decade of theoretical spectra. This characterization utilizes annual and monthly averages of irradiance-weighted APEs. The results indicate a difference of only 0.2% between the average annual APE for the decade and the annual ground-based experimental APE. Additionally, the theoretical monthly APEs for the decade show a seasonality consistent with our experimental data for the summer months but not for the winter months.
Energy analysis of a nZEB standard residential building: case study in Rio de JaneiroVitória, V H; Meiriño, M J; Figueiredo, G
doi: 10.1088/1742-6596/2180/1/012015pmid: N/A
This research aims to identify the technical feasibility of the concept of Nearly Zero Energy Building according to Brazilian standards and climatic conditions. The analysis was performed under the most up-to-date normative references and through computational energy simulation via EnergyPlus software, focusing on the building envelope model of a residential building in Rio de Janeiro. A reference model and five other construction models common in the national market were analyzed in two scenarios: firstly, in terms of natural ventilation only, and then using natural ventilation alternating with artificial cooling. Although those models were shown to be in the scope of international benchmarks about energy consumption in warm climate areas, some models stood out. In this case, the model with the lowest energy consumption presented results 22% lower than the reference model. This model was then associated with a supply of solar photovoltaic energy in order to apply one of the fundamental requirements of nZEB: the use of renewable energy sources. The results show the potential for nZEB implementation in Brazil.
The potential of energy storage systems associated with PV generation to postpone investments in capacity expansionManito, A R A; Almeida, M P; Filho, G F P; Almeida, J C; Rodrigues, M A C; Torres, P F; Pinho, J T; Zilles, R
doi: 10.1088/1742-6596/2180/1/012010pmid: N/A
Postponement of infrastructure investment is often regarded as a potential benefit of distributed PV generation. However, PV has questionable impact on the postponement of investments for infrastructure capacity increase. This paper evaluates under which conditions and to which extent distributed photovoltaics and energy storage systems are able to aid the distribution system in terms of alleviating the loading of feeders. The methodology consists of a sensitivity analysis, in different demand and generation scenarios, on the impacts that photovoltaic generation and energy storage systems would have in alleviating distribution feeders. In each scenario, the synergy between energy storage and PV generation is evaluated by estimating the amount of energy storage capacity needed to reduce the peak demand to a desired level. Results show that the existence of PV generation may reduce the storage capacity needed (and consequently the cost) to achieve a desired peak demand reduction only if proper conditions are found in the demand curve.
Application of a bioclimatic tool for the hygrothermal analysis of a historic building in Lima-PeruAlvarez, S; Lefebvre, G
doi: 10.1088/1742-6596/2180/1/012013pmid: N/A
The main objective of this paper is to know and analyze the bioclimatic strategies that would be present in colonial residential architecture in Lima. The knowledge and use of systems to achieve certain climate conditions in ancient buildings made of sun-dried bricks and thatch, both in open and closed spaces. We consider that through trial-and-error approaches, techniques would have been developed to obtain indoor comfort considering local climate conditions, available materials and other cultural conditions. Temperature, humidity and air speed measurements were taken three times a day during four days in some places of the building. Givoni’s building bioclimatic chart is used to analyze the performance of the places measured. On the one hand, different climate conditions were recorded in each patio and would be the result of its physical characteristics. In addition, differences between the performance of social spaces and private rooms were observed due to different ventilation strategies.
Photovoltaic acai (Euterpe oleracea Mart.) berry juice extractor machineFeijão, A T; Almeida, A M G; Brito, A U
doi: 10.1088/1742-6596/2180/1/012004pmid: N/A
This project is about the development of a product called the photovoltaic acai (Euterpe oleracea Mart.) berry juice extractor machine, which comes as a technological alternative to solve one of the problems resulting from the lack of commercial supply of electricity in remote areas of the Amazon. It is a utility model patent, which employs equipment available in the local market, designated initially to operate in conventional electrical supply however operationally configured for photovoltaic solar power systems. This machine configuration consists of an “acai mixer”, a three-phase induction motor, a three-phase variable-speed drive and a photovoltaic generator. The photovoltaic acai (Euterpe oleracea Mart.) berry juice extractor machine is characterized as a photovoltaic system isolated from the conventional power grid and it is of the type of direct coupling. The results of the tests performed in the lab revealed that the prototype could produce up to 126 L/day of acai berry juice in a single day. However, the production of only 28 L/day is able to amortize the investment within two years.
Prefacedoi: 10.1088/1742-6596/2180/1/011001pmid: N/A
The Peruvian Solar Energy Workshop (JOPES by its Spanish acronym) has been held annually since 2018. In 2021, due to the restrictions caused by the Covid 19 pandemic, was the second time JOPES has been organized virtually, using the Zoom platform from the National University of Engineering, in Lima, Peru. The organizers of the event came from both national and international universities and research centersDuring the three days of the event, there were nine keynote speakers, six came from Latin American countries (Argentina, Brazil, Chile, Mexico, and Peru) and two from European countries (Sweden and Czech Republic). They had 40 min (30 + 10 Q&A).In addition, there were 31 speakers presenting their research work, including 22 Peruvians, 6 Brazilians, a Mexican, a Spanish, and an Indian. They had 20 min (15 + 5 Q&A).During these years JOPES has been positioning itself as a national and Latin American platform where research works related to energy and environmental alternatives are presented and discussed. We consider that this activity represents a small but concrete contribution to achieving equitable and sustainable development for a modern society.Organizing CommitteeGerardo Cruz CerroUniversidad Nacional de TumbesTumbes, PeruErich Saettone OlschewskiUniversidad de LimaLima, PeruAmaru Palomino TöfflingerPontificia Universidad Católica del PerúLima, PeruJosé Solis VelizUniversidad Nacional de IngenieríaLima, PeruEner SalinasHitachi Energy ResearchVästerås, SwedenMónica Gómez LeónUniversidad Nacional de IngenieríaLima, Peru
Soiling accumulation impact on PV modules installed at different tilted angles in São Paulo, BrazilMisquita, Í da S; Zilles, R
doi: 10.1088/1742-6596/2180/1/012008pmid: N/A
The present study was carried out at the University of São Paulo (USP), in the capital campus, in Butantã, São Paulo. On the rooftop of the Photovoltaic Systems Laboratory (LSF). This study used twenty photovoltaic modules with a unit power of 20 Wp. Before the beginning of the study, the modules were exposed to natural light so that they would suffer the LID effect. Subsequently, all modules were calibrated to measure the solar irradiance, using IEC 60904-2 using a pyranometer as a secondary reference sensor. After calibration, the modules were arranged in pairs, with angles ranging from 0 to 45° as reference to the surface, with a difference between pairs of 5°. To evaluate the influence of rainfall, which is the main responsible for the natural cleaning of the modules. The pluviometric values were obtained from the meteorological station of the Institute of Astronomy, Geophysics and Atmospheric Sciences of the USP. The module allocated at 0°, “Dirty” was used as reference and all the results obtained were calculated in relation to it. The results for the 18 months of experiment showed the non-linear influence of soiling, acting in a stronger way for the less inclined angles, and after 10°, this influence, became less relevant, in comparison to the previous angle. The largest losses were found for 0° and 5°, the losses exclusively to soiling were 8.16 % and 6.82 % respectively. For angles greater than 10°, the soiling effect was attenuated, which resulted in less significant losses, for 15° the difference between the impact of dirt compared to 10° was only 0.1%. Rainfall also had a very relevant impact on the experiment. This study concluded that the optimal angle, where dirt accumulation was reduced, the rainfall cleaning and relative gains were optimized is in the range between 20° and 30°.