A density‐based time‐series data analysis methodology for shadow detection in rooftop photovoltaic systems

The majority of photovoltaic (PV) systems in the Netherlands are small scale, installed on rooftops, where the lack of onsite global tilted irradiance (GTI) measurements and the frequent presence of shadow due to objects in the close vicinity oppose challenge in their monitoring process. In this study, a new algorithmic tool is introduced that creates a reference data-set through the combination of data-sets of the unshaded PV systems in the surrounding area. It subsequently compares the created reference data-set with the one of the PV system of interest, detects any energy loss and clusters the distinctive loss due to shadow, created by the surrounding objects. The new algorithm is applied successfully to a number of different cases of shaded PV systems. Finally, suggestions on the unsupervised use of the algorithm by any monitoring platform are discussed, along with its limitations algorithm and suggestions for further research

Experimental repair technique for glass defects of glass-glass photovoltaic modules – A techno-economic analysis

Solar photovoltaic (PV) energy is a crucial supply technology in the envisioned renewable energy system. With enormous amounts of PV modules being installed, some will be affected by early-life failures and the resulting e-waste from PV modules is raising environmental concerns. A failure of growing importance is the defect in the glass layer(s) of glass-glass PV modules. In this research, an experimental glass repair technique for glass-glass PV modules was tested and examined. The PV modules with glass defects under test did not show internal defects in the PV cells, while the repaired specimens performed properly at each phase in the repair process compared to reference modules, the IEC standards and manufacturer warranty. After a damp-heat test the repaired PV modules showed no signs of water ingress, suggesting that the glass layer was restored as a proper barrier. However, definite conclusions should be made with caution since the non-repaired specimens neither showed visible signs of water ingress. While the practical application of the reparation technique has still some uncertainties, glass reparation is found to be technically feasible and effective. Furthermore, economic and energetic analyses indicate that glass defect reparation is economically interesting and energetically desirable

A novel design and simulation of a mechanical coordinate based photovoltaic solar tracking system

Various methods have been developed to increase electrical energy production gains in photovoltaic (PV) systems. These can be classified as solar tracking systems, cooling systems and methods of reducing the effect of shading. In order to maximise the PV energy yield, the PV systems must follow the sun. In this study, the effect of solar tracking systems on the energy yield gains of PV systems is investigated, and various types of solar tracking systems are discussed in detail. To ensure accuracte tracking of the postion of the sun, a new, low-cost, system has been developed that employs a global positioning system (GPS) module, compass and accelerometer. With this necessary angle information a dual-axis coordinate-based solar tracking system was designed using the Arduino Mega 2560 microcontroler with home-built control software. The system is validated by comparing it to a fixed angle system and an energy yield gain of 33–38% is found

Predictive modeling of PV solar power plant efficiency considering weather conditions: A comparative analysis of artificial neural networks and multiple linear regression

This study investigates the surface parameters and environmental factors affecting the energy production of a 500 kWp photovoltaic (PV) solar power plant in Igdir province. Using both the PV panel characteristics and the weather conditions specific to the power plant location, a total of 7 detailed features were included. The estimation of the power plant efficiency, a novel contribution not found in previous studies, is also a major focus. The performance evaluation of different models, including feed-forward neural networks and multiple linear regression, demonstrates the effectiveness of artificial neural networks in capturing the complex relationships between features and efficiency despite limited data availability. Principal Component Analysis (PCA) was used to reduce feature dimensions, showing that even with a reduced feature set, accurate efficiency prediction is still achievable. Prediction using PCA is one of the novelties of the paper. The effects of solar irradiation, module power, and module temperature on power plant efficiency are revealed. The results provide valuable insights for optimizing energy investments in the Igdir region and highlight the potential of artificial neural networks in energy forecasting, demonstrating their suitability for capturing complex patterns in solar power plant efficiency

Optimising Absorption in Luminescent Solar Concentrators constraint by Average Visible Transmission and Color Rendering Index

The luminescent solar concentrator (LSC) as energy harvesting window is an emerging technology in the realm of building integrated photovoltaics. Using recent advancement for assessing the balance between transmitted color quality and potential electricity generation, this paper optimizes theoretical luminophore absorption spectra for the highest power generation possible. The power conversion efficiencies (PCE) are based on coupling of the LSC waveguide to a highly efficient crystalline silicon solar cell. A non-convex optimisation algorithm maximizing absorption is used with constraints for color quality parameters: average visible transmission (AVT) and color rendering index (CRI). An optimal luminophore has been defined using a continuous absorption function with a cut-off and limited absorption in the visible spectrum. Two types of constraints are set: 1) 55% < AVT < 100% and 2) 55% < AVT < 100% and 70 < CRI < 100. The first constraint will ensure sufficient visible light and the second ensures appropriate color rendering. Ray-trace validated results show high power conversion efficiencies ranging from 9.53% to 14.3% for (AVT = 90%, CRI = 98) and (AVT = 55%), respectively. Future studies can use these results to benchmark (tandem) LSCs for specific lighting requirements. Furthermore, the flexibility of the proposed method allows for the adaptation to constraints not used in this paper

Comprehensive characterisation and analysis of PV module performance under real operating conditions

The specifications of photovoltaic modules show performance under standard testing conditions (STC), but only limited information relating to performance at non-STC conditions. While performance is affected by irradiance, temperature, spectral composition of irradiance, angle-of-incidence of the irradiance and other parameters, specifications only partly give detail to consumers or retailers about the effect of irradiance and temperature. In this study, we characterise and analyse the performance of eight different, commercially available photovoltaic modules. We establish the effect of four different parameters on module performance: irradiance, temperature, spectral composition of irradiance (via the parameter average photon energy) and angle-of-incidence, by performing linear and nonlinear optimisation of physical or empirical models. Furthermore, we characterise the operating conditions and analyse the seasonal and annual development and contribution of the four parameters to energy losses or gains relative to STC operating conditions. We show a comprehensive way of presenting the deviation of performance from STC, combining the variation in operating conditions and the resulting variation in performance. Our results show that some effects on performance are attributable to the semiconductor material used in the modules (spectral composition and temperature), while especially angle-of-incidence effects seem more related to the type of glass used on as the front cover of the module. Variation in irradiance and module temperature generally affect performance the strongest, resulting in a performance effect ranging from + 2.8% to − 3.2% and − 0.5% to − 2.2%, respectively. The combined effect of all parameters results in an annual yield deviation ranging from + 1.2% to − 5.9%

Facades, roofs and solar parking yield estimation at Utrecht science park

In this paper a methodology is described combining 2D height maps with 3D building simulations and PV performance software to assess the solar potential at Utrecht Science Campus. Results show that adding facades and parking lots doubles the roof potential, with levelized cost of energy values of 0.068 - 0.092 €/kWh

Analysis of the 1 Year Outdoor Performance of Quantum Dot Luminescent Solar Concentrators

Three quantum dot luminescent solar concentrators (QDLSCs) are constructed to assess their performance in an outdoor environment over an entire year. The QDLSCs have a (Formula presented.) PMMA-Kraton-PMMA sandwich structure with either InP/ZnSe/ZnS, (Formula presented.), or CdSe/CdS/ZnS core/shell quantum dots incorporated in the Kraton interlayer. Furthermore, two reference LSCs are included: one using Lumogen F Red 305 as the luminophore and one without a luminophore in the Kraton layer. The power conversion efficiency is assessed for a cloudy and a sunny day, showing the influence of diffuse and direct irradiance. Moreover, the influence of mounting orientation and direct irradiance is analyzed for individual solar strips attached to the sides. Long-term results show an efficiency increase of (Formula presented.) and InP/ZnSe/ZnS QDLSC while the CdSe/CdS/ZnS QDLSCs and the Lumogen LSC show a pronounced drop in efficiency in the first 3 months. Photodegradation studies under continuous white light exposure for 420 h are performed on smaller pieces cut from the QDLSCs before their assembly outdoors and show similar trends to those observed in the 1 year outdoor study. Future research will focus on the postmortem analysis of the QDLSCs and increasing the efficiencies

Analysis of photon-driven solar-to-hydrogen production methods in the Netherlands

Hydrogen is deemed necessary for the realization of a sustainable society, especially when renewable energy is used to generate hydrogen. As most of the photon-driven hydrogen production methods are not commercially available yet, this study has investigated the techno-economic and overall performance of four different solar-to-hydrogen methods and photovoltaics-based electrolysis methods in the Netherlands. It was found that the photovoltaics-based electrolysis is the cheapest option with production cost of 9.31 $/kgH2. Production cost based on photo-catalytic water splitting, direct bio-photolysis, and photoelectrochemical water splitting are found to be 18.32$/kgH2, 18.45 $/kgH2, and 18.98$/kgH2, respectively. These costs are expected to drop significantly in the future. Direct bio-photolysis (potential cost of 3.10 $/kgH2) and photo-catalytic water splitting (3.12$/kgH2) may become cheaper than photovoltaics-based electrolysis. Based on preferences of three fictional technology investors, i.e. a short-term, a green and a visionary investor, the overall performance of these methods are determined. Photovoltaics-based electrolysis is the most ideal option, with photoelectrochemical water splitting a complementary option. While photovoltaics-based electrolysis has an advantage on the short-term because it is a non-integrated energy system, on the long-term this might lead to relatively higher cost and performance limitations. Photochemical water splitting are integrated energy systems and have an advantage on the long-term because they need a relatively low theoretical overpotential and benefit from increasing temperatures. Both methods show performance improvements by the use of quantum dots. Bio-photolysis can be self-sustaining and can use wastewater to produce hydrogen but sudden temperature changes could lead to performance decrease