Search

The paper describes the research on optical properties of glass/ITO/Ag thin layers obtained on glass/ITO substrates with different properties. The authors will discuss the influence of silver particles and silver layer thickness on the transmission and reflection spectra of the layers and parameters, such as the width of the optical band gap, refractive index, and dieelectric function. For example, the presence of silver leads to a decrease in the transmission of the layers (compared to ITO/glass) regardless of the thickness of the silver layer, and in the case of reflection, both its increase and decrease were observed, depending on the thickness of the silver layer and the type of glass/ITO substrate used. The average transmission value in the visible region depends on the thickness of the silver nanoparticle layer and varies from ~50% to ~90%. The average refractive index takes values from the range ~1.4 to ~1.65 and does not depend on the presence and thickness of the silver layer.

International audience; Over the last decade, the rating of photovoltaic power stations has increased progressively; however; they still operate at low voltage (below 1500VDC for PV string side and below 800VAC-3~ for the power injection side. Hence, new architectures with an intermediate MVDC collector are investigated. This paper introduces a new topology of isolated DC/DC converter based on 1.7-kV and 3.3-kV SiC power modules, which allows the connection of PV panels to a MVDC collector upstream from the MVAC distribution grid. As a prelude to the realization of a full-scale prototype, 1.7 kV SiC MOSFETs are characterized in hard- and soft-switching condition. Finally, a study supported by simulations pointed out that the proposed converter shows a high efficiency (> 98.5%)

Esta ponencia forma parte de: XLII Jornadas de Automática En este trabajo se propone una metodología para dimensionar el sistema de almacenamiento de un sistema híbrido con fotovoltaica (FV) para uso doméstico, a partir de predicciones probabilísticas de la producción solar. Se introduce para ello un modelo basado en Deep Learning que, a partir de estimaciones de la irradiancia pasada en el área que rodea la localización objetivo, obtiene las predicciones de distintos percentiles de la producción FV. El dimensionamiento se realiza mediante una optimización lineal que utiliza la función cuantil para garantizar, con un cierto nivel de confianza, que se satisface un perfil de demanda tipo. Finalmente, se introducen y discuten resultados en cuanto a la violación de restricciones que se produce con diferentes tamaños del sistema de almacenamiento mostrándose que, cuando este es superior a 3 h a potencia nominal de la instalación FV, las restricciones se satisfacen en más del 99 % de las ocasiones. In this work, a methodology is proposed to size the storage system of a hybrid photovoltaic (PV) system for domestic use, based on probabilistic predictions of solar production. To do so, a model based on Deep Learning is introduced which, based on estimates of past irradiance in the area surrounding the target location, obtains the forecasts of different percentiles of PV production. Sizing is carried out through a linear optimization that uses the quantile function to guarantee, with a certain level of confidence, that a typical demand profile is satisfied. Finally, results are introduced and discussed regarding the violation of constraints that occurs with different sizes of the storage system, showing that, when they are greater than 3 h at the nominal power of the PV installation, the constraints are satisfied in more than 99 % of the occasions.

International audience

Esta ponencia forma parte de: XLII Jornadas de Automática En este trabajo se propone una metodología para dimensionar el sistema de almacenamiento de un sistema híbrido con fotovoltaica (FV) para uso doméstico, a partir de predicciones probabilísticas de la producción solar. Se introduce para ello un modelo basado en Deep Learning que, a partir de estimaciones de la irradiancia pasada en el área que rodea la localización objetivo, obtiene las predicciones de distintos percentiles de la producción FV. El dimensionamiento se realiza mediante una optimización lineal que utiliza la función cuantil para garantizar, con un cierto nivel de confianza, que se satisface un perfil de demanda tipo. Finalmente, se introducen y discuten resultados en cuanto a la violación de restricciones que se produce con diferentes tamaños del sistema de almacenamiento mostrándose que, cuando este es superior a 3 h a potencia nominal de la instalación FV, las restricciones se satisfacen en más del 99 % de las ocasiones. In this work, a methodology is proposed to size the storage system of a hybrid photovoltaic (PV) system for domestic use, based on probabilistic predictions of solar production. To do so, a model based on Deep Learning is introduced which, based on estimates of past irradiance in the area surrounding the target location, obtains the forecasts of different percentiles of PV production. Sizing is carried out through a linear optimization that uses the quantile function to guarantee, with a certain level of confidence, that a typical demand profile is satisfied. Finally, results are introduced and discussed regarding the violation of constraints that occurs with different sizes of the storage system, showing that, when they are greater than 3 h at the nominal power of the PV installation, the constraints are satisfied in more than 99 % of the occasions.

[Resumen] Este trabajo define una estrategia de operación basada en Control Predictivo basado en Modelo (Model Predictive Control, MPC) para instalaciones fotovoltaicas con baterías instaladas en el sector terciario/comercial. La propuesta incluye modelos de predicción de la irradiancia a futuro y modelos de consumo de las cargas basados en técnicas de agrupamiento. La operación del sistema se simula durante un año entero con datos de irradiancia y consumo reales para un centro comercial situado al sur de España. Finalmente, se analiza la rentabilidad del sistema, en términos de vida útil de las baterías requeridas para lograr el retorno de la inversión realizada, para diferentes combinaciones de sistema FV, tamaño de las baterías, y precios de la energía. [Abstract] This work defines a strategy of operation based on Model Predictive Control (MPC) for a PV application with an energy storage system (ESS) in the commercial sector. Prediction models of future irradiance and loads consumption based on clustering techniques are also introduced. The operation is simulated for a whole year with real irradiance data in a southern spanish location and with real consumption values from a shopping center. Finally, profitability of the system, in terms of required lifetime of the ESS for the return of the investment, is analyzed for different scenarios of PV system, battery capacities and energy prices. Universitat Jaume I; UJI-B2017-26

[Resumen] Este trabajo define una estrategia de operación basada en Control Predictivo basado en Modelo (Model Predictive Control, MPC) para instalaciones fotovoltaicas con baterías instaladas en el sector terciario/comercial. La propuesta incluye modelos de predicción de la irradiancia a futuro y modelos de consumo de las cargas basados en técnicas de agrupamiento. La operación del sistema se simula durante un año entero con datos de irradiancia y consumo reales para un centro comercial situado al sur de España. Finalmente, se analiza la rentabilidad del sistema, en términos de vida útil de las baterías requeridas para lograr el retorno de la inversión realizada, para diferentes combinaciones de sistema FV, tamaño de las baterías, y precios de la energía. [Abstract] This work defines a strategy of operation based on Model Predictive Control (MPC) for a PV application with an energy storage system (ESS) in the commercial sector. Prediction models of future irradiance and loads consumption based on clustering techniques are also introduced. The operation is simulated for a whole year with real irradiance data in a southern spanish location and with real consumption values from a shopping center. Finally, profitability of the system, in terms of required lifetime of the ESS for the return of the investment, is analyzed for different scenarios of PV system, battery capacities and energy prices. Universitat Jaume I; UJI-B2017-26

31st European Photovoltaic Solar Energy Conference and Exhibition; 2873-2878, The average per capita electricity demand in India in the year 2010 is about 884KWh1 which may be much lower than that of the developed countries like USA, Europe, Australia, Japan etc. but this figure is expected to rise sharply due to an economic growth rate of 8.9%, which is the second fastest in the world2. Energy is a necessity and sustainable renewable energy is a vital link in industrialization and development of India. A transition from conventional energy systems to those based on renewable resources is necessary to meet the ever increasing demand for energy and to address environmental concerns.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3625-3629, An assessment of roof-mounted PV capacity over a local region can be accurately calculated by established roof segmentation algorithms using high-resolution light detection and ranging (LiDAR) datasets. However, over larger city regions often only low-resolution LiDAR data is available where such algorithms prove unreliable for small rooftops. A methodology optimised for low-resolution LiDAR datasets is presented, where small and large buildings are considered separately. The roof segmentation algorithm for small buildings, which are typically residential properties, assigns a roof profile to each building from a catalogue of common profiles after identifying LiDAR points within the building footprint. Large buildings, such as warehouses, offer a more diverse range of roof profiles but geometric features are generally large, so a direct approach is taken to segmentation where all the LiDAR points are considered individually and then connected segmentally. The methodology is demonstrated by application to the city region of Leeds, UK. Validation by comparison to aerial photography indicates that the assignment of an appropriate roof profile to a small building is correct in 81% of cases.

The paper presents a comparative study of two solar string inverters based on the Quasi-Z-Source (QZS) network. The first solution comprises a full-SiC two-level QZS inverter, while the second design was built based on a three-level neutral-point-clamped QZS inverter with Silicon based Metal–Oxide–Semiconductor Field-Effect Transistors (Si MOSFETs). Several criteria were taken into consideration: the size of passive elements, thermal design and size of heatsinks, voltage stress across semiconductors, and efficiency investigation. The Photovoltaic (PV)-string rated at 1.8 kW power was selected as a case study system. The advantages and drawbacks of both solutions are presented along with conclusions.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2676-2679, In order to have both predictable power demand and supply, in accordance with an increased selfconsumption of PV generated electrical energy, it seems natural to coordinate the installed PV units with consuming and storing devices inside a locally build-up smart grid. By the generation, storage and consumption of power in one´s own home but also by sharing between users in an integrated neighbourhood, energy production and demand can be coordinated when it includes sharing of information for exchange excess power and storage capacity, inside smart neighbourhood grids and the external power grid. Consequently households are equipped with additional ICT based hardware for measuring, controlling and optimizing their energy consumption and generation. In order to test and prove this underlying technology under real conditions, field tests with collaborating users are already underway in Konstanz (Germany) and will continued and extended at user sites in the Province of Caserta (Italy).

31st European Photovoltaic Solar Energy Conference and Exhibition; 2780-2783, This paper describes the optimized power development including PV and CSP in Saudi Arabia in terms of LCOE (Levelized Cost of Energy) as well as its potential influence to the GDP of the Kingdom. Saudi Arabia is facing a rapid increase in power demand due to increasing population and the economic growth. Domestic consumption of oil could reach the recent production level in less than 20 years at this rate. As the potential of increase in oil production is limited, substitution of oil by other sources of energy as well as energy conservation is critical. To cope with this problem, a simulation model which consists of two modules is proposed in this article in order to evaluate the proposed target values by the government and to suggest the optimized power supply plan. The first module is Electricity Simulation Module that aims LCOE minimization of the power system, potentially consisting of PV, CSP, nuclear and thermal power. The second module is the Macroeconomic Module calculating the GDP for each scenario in power development. The estimated future I/O table for Saudi Arabia has been extended to include PV, CSP and nuclear industrial sectors. The influence to the GDP has been compared between the two scenarios.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2686-2689, With a decrease in feed-in tariffs for photovoltaic (PV) systems in Europe and a decrease in the cost of Li-ion batteries, PV battery systems for increased self-consumption are becoming of increasing interest. A 4.8 kWh PV battery system with lithium iron phosphate (LiFePO4) batteries was designed. The battery pack was installed with the commercially available LiTHIUM BALANCE A/S battery management system that manages the battery cells for achieving higher yield and increased service life of the battery packs. The PV battery system was installed in the EnergyFlexHouse at Danish Technological Institute, a full-scale flexible measurement platform for construction and installation technology. This gave the possibility to test the PV battery system in a single-family house environment. The PV battery system was connected to a PV array of 3.5 kWp. High resolution consumptions data for typical single family households was used for minute by minute load simulation in the tested PV battery system. Economic calculations based on Danish feed in tariffs are calculated for a PV battery system and a PV system without battery to clarify if it is profitable for a Danish consumer to install a PV battery. Economic calculations shows that a PV battery system could potentially stimulate the demand for PV systems despite decreasing feed in tariffs.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2703-2708, Most of the installed PV storage systems in residential areas are installed in single family houses. The field of application of PV storage systems can be extended to apartment buildings by providing a concept, that allows the joint use of one PV storage system by a number of apartments. This paper describes a concept, that combines an integrated multi-level energy management system for an apartment building with a PV generator and a storage unit. Therefore a measurement concept is introduced, that allows quasi-real-time metering and simultaneous multiple access to one battery storage unit. The global objective is to present a holistic concept, that provides an energy management system that optimizes on the level of the apartment, the whole building and the integration in the energy market all in one.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2767-2769, There are two main ways to convert and use the solar energy. The first one is conversation of solar energy into thermal and the second one is solar energy conversion into electrical energy through semiconductor photovoltaic cells. In the recent years, numerous researches have been made for the development of solar photovoltaic and thermal hybrid systems which provide electrical and thermal energy simultaneously. Hybrid systems are often integrated with solar concentrating devices. In these systems it is important to remove the heat from the semiconductor converter. The hybrid systems are composed of different knots and quite complicated. Consequently for the design and moreover for optimal design of the mentioned systems it is necessary to develop an appropriate mathematical model and a software package. For that propose the mathematical model of the solar hybrid (concentrated and non-concentrated) systems is considered in this work which enables to estimate the electrical and the thermal energy produced by a solar hybrid system, the size of the surface and the amount of heated water during a day. As well as the analysis of characteristics of hybrid systems were performed.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2925-2929, This paper describes the modelling of components and control strategies for PV-diesel hybrid systems without energy storage, which have been implemented in an online and free-software simulator of PV systems called SISIFO, which is publicly available at www.sisifo.info. Among other features, this software tool allows the prediction of fuel savings for different sizes and types of PV generators, the comparison of selected control strategies and the evaluation of the spinning reserve requirements in systems with multiple diesel generators operating in parallel.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2854-2856, The architectural award for building-integrated solar technology granted by the Bavarian Association for the Promotion of Solar Energy (abbreviated as SeV) in 2014, aims at promoting excellence in planning and designing of building-integrated solar power systems. This award makes accessible the exemplary solutions in qualitatively sophisticated architecture to the greater public. However, not only the architectural quality of the buildings should be considered, the energetic behavior of the building influenced by the building-integrated solar power systems, should be considered. For a few sample systems the energy system and the energy balance have been investigated. One large building acts as a power station and generates 260 % of the electric energy consumed inside. The other buildings generate within one year nearly the electric energy the building needs.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2930-2932, Elkaria is a remote rural village located in the middle of Morocco which enjoys an average daily solar irradiation of 6kW/m²/day. This potential was exploited to supply the village with electricity using a standalone PV plant with a peak power of 7.2 kWp and an 1100 Ah battery bank. The plant feeds the 16 households of the village by electricity using an isolated grid. In this work, the Renewable Fraction (RF) and Cost of Electricity (COE) were evaluated for this plant in two situations: 1) standalone mode with energy storage, and 2) grid-connected mode with no storage. Homer 2.81software was used in this study to economically and environmentally evaluate the feasibility of these configurations. The village load curve was determined from previous measurements while the solar radiation data are obtained from PVGIS Africa and compared with onsite measured values. The prices used are the actual costs of the system components. The results show that the second case is more optimal than the first presenting a RF of 0.71, and a COE of 0.103$/kWh against a RF of 1 and COE of 0.523 $/kWh for the first case.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2882-2885, In the year 2014 it is the sixth time the Bavarian Association for the Promotion of Solar Energy (abbreviated as SeV) has sponsored a competition dedicated to integrating solar technology into architecture. This architectural award for building-integrated solar technology aims at promoting excellence in planning and designing of building-integrated solar power systems. This award makes accessible the exemplary solutions in qualitatively sophisticated architecture to the greater public. The entries submitted for the competition in 2014 show how architects have become increasingly interested in solar technology. Within the projects submitted, housing construction continues to make up the largest share with more than 35 percent, whereby almost three-quarters are detached and semi-detached homes. The other building types are largely distributed between industrial /commercial (15 per cent), administration (11 percent) and municipal buildings (10 percent), as well as schools/kindergarten (8 percent). The majority of submissions are new-build schemes, even if the refurbishment examples show that it is also possible to successfully integrate solar technology into existing roofs and facades.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2848-2853, Methods of utilizing residential produced photovoltaic (PV) power by converting to thermal energy through heat pumps (HP) are present in literature, where thermal energy is dispersed as either heat or hot water at the instant moment of PV production. In this paper an alternative solution is described, where the thermal energy is stored in a buffer tank (BT) capable of dispersing heat to either the heating system of a house or a hot water tank, for later use. The thermal storage solution including a BT can increase the self-consumption of residentially produced PV power and thereby shift electric energy demand of the HP to hours where excess PV power is present. The self-consumption of the PV energy affects the overall net present value (NPV). In this paper, a method which maximizes the NPV by finding the cost-optimal combination of PV, HP and BT sizes, is proposed. Results show that the thermal storage with a BT is a better investment than a PV system without HP or no investment. Furthermore, it showed that the optimization model developed in this project is capable of finding the optimal combination of component sizes based on our data.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2867-2872, These works are dedicated to the development of solar power installations integrated into the outer bearing construction, into the dome structure of a noospheric building and the central part of building that can supply electric power, heating and lighting. Noospheric buildings are as a perspective design concept for well-balanced and comfortable life in terms of energy efficiency, environmental safety, economics, bioenergetics and ergonomics. Noospheric building shape (that of dome or paraboloid) is the optimal in terms of solar system (energy supply system of building) output minimization regarding the form of buildings as the optimization parameter. The Specific design features of such buildings provide large opportunities for implementing solar energy based power systems that make it possible to integrate solar power installations into the building structure providing an extensive variety of solar energy usage options. With this approach a high level of solar systems efficiency can be achieved.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2745-2750, With increasing population shifts to urban areas and demands for post-war energy efficient renovations across Europe, solar photovoltaic (PV) deployment in multi-family housing will play an increasingly important role towards meeting renewable energy, climate, and sustainability goals. This paper describes the stories of three Swedish residential cooperatives who have installed large-scale PV systems across multiple buildings on their estates. In all cases, reduced operating costs were the original primary motivator; however unforeseen cost increases, changes in policy, and excess supply in the electricity market have made economic success less likely than originally expected. Regardless, the owners consider their projects a success due in part to short term social and long-term environmental benefits, which were originally less important and difficult to quantify. We can conclude that community owned PV offers more than just economic benefits, and Sweden’s unique ownership and management structure of residential cooperatives can offer insights towards increased deployment in other nations in Europe.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2718-2725, The aim of this research was to develop frameworks to better understand the role of community engagement, and assist in planning community engagement strategies in order to enhance the sustainability and transformative potential of PV hybrid mini grids for remote developing regions. Transformative potential is defined as the ability of a modern energy service to effectively alleviate energy poverty and meet sustainable livelihoods. Through the use of literature review, case studies and interviews with industry practitioners, this research produced a phase by phase guide to community engagement opportunities within PV hybrid mini grid deployment models, an evaluation tool for assessing sustainability and transformative potential of a PV hybrid mini grid program and recommendations for best practice in order to maximise sustainability and transformative potential of a PV hybrid mini grid program. Key considerations include the resource intensive nature of community engagement strategies and the importance of flexibility. It is intended that this research engender a better understanding of the value of community engagement, and how it can be realised in different in deployment models.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2628-2632, As semi-transparent photovoltaic windows are advancing within the building and window industry, the need for deeper understanding and quantification of their thermal and electrical behaviour is paramount. The objective of this work is to study and predict the thermal response and electric performance of a typical double-glazed insulated unit integrating STPV technologies on its outer glass layer. PV operating cell temperatures of up to 55.3°C were measured through an experimental study of a prototype STPV window. A numerical model was developed and verified based on the experimental data. The simulations showed that the highest operating cell temperatures occurred during the fall season with operating cell temperatures of up to 60°C, for a south-facing office façade incorporating STPV windows, located in Toronto, Canada.