Innovative Model based on the Irradiance-Temperature Fitting of Equivalent Circuit Parameters for Commercial Photovoltaic Modules towards Accurate Power and Energy Prediction

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Hourly Simulation of Energy Community with Photovoltaic Generator and Electric Vehicle

Europe has set the ambitious goal to become the first carbon-neutral continent by 2050. Therefore, it has undertaken several initiatives to promote the energy transition, including the active participation of citizens in the energy sector. In this context, recent European directives introduced the concept of energy community, whose members can consume, share, and store energy locally produced. This work proposes an energy and economic simulation of a renewable energy community powered by a 19.2 kWp photovoltaic system in the province of Cuneo, in Piedmont (Italy). The community consists of a prosumer, which owns the photovoltaic system and a charging station for electric vehicles, and other 17 energy users. Suitable indicators to assess the energy performance of the community (self-consumption and self-sufficiency) were evaluated starting from the estimated production and consumption power profiles. Then, an economic simulation was carried out to assess the economic return on the investment for the member who bore the initial costs and the annual economic savings for the others

A Smart Battery Management System for Photovoltaic Plants in Households Based on Raw Production Forecast

A basic battery management system (BMS) permits the safe charge/discharge of the batteries and the supply of loads. Batteries are protected to avoid fast degradation: the minimum and maximum state-of-charge (SOC) limits are not exceeded and fast charge/discharge cycles are not permitted. A more sophisticated BMS connected to a photovoltaic (PV) generator could also work with the double purpose of protecting storage and reducing peak demand. Peak reduction by storage generally requires the forecast of consumption and PV generation profiles to perform a provisional energy balance. To do it, it is required to have accurate information about production profiles, that is, to have at disposal accurate weather forecasts, which are not easily available. In the present work, an efficient BMS in grid-connected PV plants for residential users is described. Starting from raw 1-day ahead weather forecast and prediction of consumption, the proposed BMS preserves battery charge when it is expected high load and low PV production and performs peak shaving with a negligible reduction in self-sufficiency

Improvement of self-sufficiency for an innovative nearly zero energy building by photovoltaic generators

In the present work, a case study of an innovative nearly Zero Energy Building (nZEB) for academic purposes is investigated. In particular, its primary energy vector is electrical, i.e. a Photovoltaic (PV) generator is coupled with storage units and supplies the electrical loads and the thermal demand, which is converted into electrical by heat pumps. The system is designed to maximize the self-sufficiency and minimize the absorption from the grid. Moreover, the nZEB is equipped with sensors that are oriented to smart metering in order to monitor the energy exchange between the rooms of the building. An energy simulation is performed on a yearly basis, evaluating the size of the batteries, to reach the optimal compromise between benefits, in terms of self-sufficiency, and costs

the use of drones in the maintenance of photovoltaic fields

Enel Green Power is an Italian company which realises and manages large photovoltaic (PV) plants around the world. The company is involved in a huge number of research projects and one of them involves the use of drones for PV inspection in order to guarantee the correct operation of the plants. In this paper, the use of drones the maintenance of PV plants is analysed from a technical and economic point of view, as function of plant size. First, the use of drones for thermography and visual inspection is briefly described, then, on the basis of on-field activities, the technical specifications of drones and the procedure for the inspection are defined. The results of a thermal infrared analysis performed on six PV plants are analysed. In particular, the failure rates of PV modules are estimated, describing each failure. Finally, an economic analysis is performed in order to evaluate the competitiveness of drones for PV inspection compared to manual maintenance

Long Term Wind Turbine Performance Analysis Through SCADA Data: A Case Study

Performance monitoring of horizontal-axis wind turbines is a complex task because they operate under nonstationary conditions. Furthermore, in real-world applications, there can be data quality issues because the free stream wind speed is reconstructed through a nacelle transfer function from cup anemometers measurements collected behind the rotor span. Given these matters of fact, one of the objectives of the present work is applying an innovative method for correcting the nacelle wind speed measurements, which is based on the manufacturer power curve and statistical considerations. Three operating wind turbines, having 2 MW of rated power and owned by the ENGIE Italia company, are contemplated as test cases. Operation data spanning ten years (2011–2020) are studied: actually, this work aims as well at contributing to the methods for estimating the performance decline with age of wind turbines, basing on long term SCADA data analysis. The raw and corrected wind speed measurements are fed as input to a Support Vector Regression for the power curve: by selecting appropriately the training and validation data sets, it is possible to estimate the average yearly rate of performance decline. Using the corrected wind speed, the estimate obtained in this study is compatible with the most recent findings in the literature, which indicate a -0.17% decline per year

Towards the Complete Self-Sufficiency of a nZEBs microgrid by Photovoltaic Generators and Heat Pumps: Methods and Applications

The present paper proposes a multidisciplinary procedure to correctly design a microgrid of all-electric nZEBs (nearly Zero Energy Buildings) from both electrical and thermal points of view. The procedure is suitable for new buildings supplied by local renewables, without the use of fossil fuel and with zero emissions. First, the thermal demand of each single nZEB is assessed, as a function of the installation site, building layout and physics, and material composing the envelope. Thanks to heat pumps, the thermal demand is transformed in electric load. Thus, the total electric consumption profiles, which include user's appliances and heating/cooling, are studied and compared with Photovoltaic (PV) generation supported by electrochemical storages. Both PV and batteries are simulated thanks to appropriate models. Regarding the PV production assessment, the present work proposes an improvement with respect to the use of traditional models, and it is based on experimental results on PV generators of recent production. The design methodology is applied to a real case of “energy community” composed of three nZEB units, that will be built in the campus of Politecnico di Torino, available to students and staff. The three units share PV production and storage capacity to reach the complete grid-independence

Self-Consumption and Self-Sufficiency in Photovoltaic Systems: Effect of Grid Limitation and Storage Installation

This paper presents a methodology to maximize the self-sufficiency or cost-effectiveness of grid-connected prosumers by optimizing the sizes of photovoltaic (PV) systems and electrochemical batteries. In the optimal sizing procedure, a limitation on the maximum injection in the grid can affect the energy flows, the economic effectiveness of the investments, and thus the sizing results. After the explanation of the procedure, a case study is presented, and a parametric analysis of the effect of possible injection limits is shown. The procedure is applied to size plants for an Italian domestic prosumer, whose electric load profile was measured for a year. A software program developed using the proposed methodology is also briefly presented. It is used for both research and educational purposes, both in laboratory classes and in remote lesson

An Innovative Method to Evaluate the Real Performance of Wind Turbines: Case Study from Mauritania

The power-wind speed curve of a Wind Turbine (WT) is measured by the manufacturer in ideal conditions, and the wind speed is detected at the entrance of the WT rotor. However, in wind power plants, this quantity is rarely available because, generally, the wind speed is measured by an anemometer behind the WT. In this case, this value is lower than the wind speed at the entrance of the WT rotor. As a result, the WT performance, evaluated using these wind speed data, may be unrealistic. Thus, their correction is performed by a technique similar to instrument calibration in which the data distribution is compared with the wind speed of the manufacturer's power curve. In this context, the present work proposes an innovative method to correctly assess the performance of WTs. In particular, it is based on the manufacturer curve, correcting the wind speeds measured behind the WTs rotor. The correction is applied to one WT (rated power = 2 MW) of a wind farm in Mauritani

Synergistic freshwater and electricity production using passive membrane distillation and waste heat recovered from camouflaged photovoltaic modules

A sustainable supply of both freshwater and energy is key for modern societies. In this work, we investigate a synergistic way to address both these issues, producing freshwater while reducing greenhouse gas emissions due to electricity generation. To this, we propose a coupling between a photovoltaic (PV) device and an innovative desalination technique based on passive multi-stage membrane distillation. The passive distillation device is driven by low-temperature heat and does not need any mechanical or electrical devices to operate. The required heat is recovered from the back side of the PV device that, for the first time, mitigates the aesthetic and environmental impact thanks to an innovative surface texture. The aim is to demonstrate the feasibility to generate PV electricity from the sun and, simultaneously, freshwater from the waste heat. The solution is studied by numerical simulations and experiments at the same time, achieving a good accordance between these two approaches. The device is able to produce up to 2 L m-2 h-1 of freshwater under one sun irradiance. Furthermore, a relative photovoltaic efficiency gain of 4.5% is obtained, since the temperature of the PV module is reduced by 9 °C when coupled with the desalination technology. This work paves the way to compact installations made of such passive units, which may easily provide energy and safe water with low environmental and visual impact, especially in off-grid areas and emergency conditions