Photovoltaics

Maximum power point tracking (MPPT) is necessary for photovoltaic (PV) systems to collect the maximum photovoltaic array power under variations in the insolation and temperature. This paper presents an artificial neural controller for maximum power point tracking of photovoltaic system based on back- propagation algorithm. The tracking algorithm changes the duty cycle of the DC-DC converter so that PV module voltage equals the voltage corresponding to the MPPT at any given insolation level and temperature conditions.

This work approximates the selective harmonic elimination problem using artificial neural networks (ANNs) to generate the switching angles in an 11-level full-bridge cascade inverter powered by five varying dc input sources. Each of the five full bridges of the cascade inverter was connected to a separate 195-W solar panel. The angles were chosen such that the fundamental was kept constant and the low-order harmonics were minimized or eliminated. A nondeterministic method is used to solve the system for the angles and to obtain the data set for the ANN training. The method also provides a set of acceptable solutions in the space where solutions do not exist by analytical methods. The trained ANN is a suitable tool that brings a small generalization effect on the angles' precision and is able to perform in real time (50-/60-Hz time window).

This paper introduces various electrical and thermal energy generation, consumption, and storage components in solar powered low-energy buildings. Dynamic management of such energy components is essential given the stochastic solar resources. Emphasis is put on power electronic HVAC (heating, ventilation, and airconditioning) drives, which can act as an effective electric swing bus to mitigate solar power variability. In doing so, grid power flows become substantially more constant, reducing the need for fast grid resources or dedicated energy storage such as batteries. The concept is equivalent to using building thermal energy as virtual dynamic storage in support of power grid operation. The paper defines a bandwidth over which such HVAC drives can operate. A practical band-pass filter is realized that provides 1) lower frequency bounds such that the building maintains consistent room temperature via the HVAC system as demonstrated by a thermal modeling study, and 2) upper frequency bounds that ensure commanded HVAC fan speeds do not update arbitrarily fast. The latter primarily avoids acoustic discomfort to users. The combination is illustrated by experimental results based on various update rates of a variable frequency fan drive over a sample of actual stochastic solar data. Building electrical and thermal energy systems modeling by MATLAB is addressed throughout the paper, including solar and HVAC systems as well as batteries and water tanks. Index Terms—Low-energy buildings, frequency domain analysis, grid-level energy storage, HVAC systems, solar energy, thermal storage, power electronic drives, complex system energy management

In order to stabilize the global climate the world’s governments must make significant commitments to drastically reduce global greenhouse gas (GHG) emissions. One of the most promising methods of curbing GHG emissions is a world transition from fossil fuels to renewable sources of energy. Solar photovoltaic (PV) cells offer a technically sustainable solution to the projected enormous future energy demands. This article explores utilizing industrial symbiosis to obtain economies of scale and increased manufacturing efficiencies for solar photovoltaic cells in order for solar electricity to compete economically with fossil fuel-fired electricity. The state of PV manufacturing, the market and the effects of scale on both are reviewed. Government policies necessary to construct a multi-gigaWatt PV factory and complimentary policies to protect existing solar companies are outlined and the technical requirements for a symbiotic industrial system are explored to increase the manufacturing efficiency while improving the environmental impact of PV. The results of the analysis show that an 8-factory industrial symbiotic system can be viewed as a medium-term investment by any government, which will not only obtain direct financial return, but also an improved global environment. The technical concepts and policy limitations to this approach were analyzed and it was found that symbiotic growth will help to mitigate many of the limitations of PV and is likely to catalyze mass manufacturing of PV by transparently demonstrating that large scale PV manufacturing is technically feasible and reaches an enormous untapped market for PV with low costs.

Large-scale development of solar-generated electricity is hindered in some regions of the U.S. by land use competition and localized social resistance. One approach to alleviate these coupled challenges is agrivoltaics: the strategic co-location of solar photovoltaics and agriculture. To explore the opportunities and barriers for agrivoltaics, in-depth interviews with solar industry professionals were conducted and findings suggest that the potential for an agrivoltaic project to retain agricultural interests and consequently increase local support for development is the most significant opportunity of dual use solar. Capable of increasing community acceptance, participants expect agrivoltaics to play an important role in future solar endeavors, especially in places where development may be perceived as a threat to agricultural interests. The results further reveal the interconnections among the various dimensions of social acceptance and suggest that the growth of agrivoltaics is c...

Agrivoltaic systems, which deliberately maximize the utility of a single parcel of land for both solar photovoltaic (PV) electricity production and agriculture, have been demonstrated as a viable technology that can ameliorate competing land uses and meet growing energy and food demands efficiently. The goal of this study is to assess the environmental impacts of a novel pasture-based agrivoltaic concept: co-farming rabbits and solar PV. A life cycle assessment (LCA) quantified the impacts of 1) the integrated agrivoltaic concept in comparison to conventional practices including 2) separate rabbit farming and PV production and 3) separate rabbit farming and conventional electricity production. The impact assessment methods employed to determine the environmental impacts were IPCC 2013 global warming potential 100a V1.03 and fossil energy demand V1.11. The results indicate that the pasture-based agrivoltaic system produces the least amount of greenhouse gas emissions (3.8 million kg ...

A Space Power Satellite capable of providing solar electric power economically for 24 hours per day has been a dream for decades. Herein, an alternative will be described. Mirrors deflecting sunbeams down to earth is a much simpler concept. While this idea is very intriguing, the magnitude of its implementation is daunting. Nevertheless, the idea is intriguing enough to proceed with a first order design for the required space mirror satellites. A first step in a development road-map could be the construction of a 12 square meter space mirror to demonstrate full moon intensity illumination in Disney Parks in the evenings. This first small space mirror could potentially be deployed on the International Space Station for testing and proof of concept experiments.

Metal chalcogenide semiconductors have a significant role in the development of materials for energy and nanotechnology applications. First principle calculations were applied on CsAgGa 2 Se 4 to investigate its optoelectronic structure and bonding characteristics, using the full-potential linear augmented plane wave method within the framework of generalized gradient approximations (GGA) and Engel-Vosko GGA functionals (EV-GGA). The band structure from EV-GGA shows that the valence band maximum and conduction band minimum are situated at C with a band gap value of 2.15 eV. A mixture of orbitals from Ag 4p 6 /4d 10 , Se 3d 10 , Ga 4p 1 , Se 4p 4 , and Ga 4s 2 states have a primary role to lead to a semiconducting character of the present chalcogenide. The charge density iso-surface shows a strong covalent bonding between Ag-Se and Ga-Se atoms. The imaginary part of dielectric constant reveals that the threshold (first optical critical point) energy of dielectric function occurs 2.15 eV. It is obvious that with a direct large band gap and large absorption coefficient, CsAgGa 2 Se 4 might be considered a potential material for photovoltaic applications.

Future energy technologies must be based on renewable sources of energy and they must be sustainable. This workshop will provide insight into unintended impacts of renewable energy and how they can be avoided. In order to steer away from the pitfalls and unintended effects it is essential that necessary knowledge is present to the developers and decision makers engaged in renewable energy. This is where this workshop is valuable in its discussion of unintended health and environmental impacts of various renewable energy technologies.
The workshop give the participants an introduction the the concept of unintended consequences, in connection with renewable energy. Furthermore, several approaches to improve the understanding of these consequences and methods for predicting them, will be discussed. This will include the concepts of rebound effects and consequential life cycle assessments (LCA). The workshop will encompass presentations and discussions of results from cross-disciplinary research on implementation of the alternative fuels hydrogen, electricity and biodiesel in the transport sector, as well as the assessment of environmental impacts from the production of solar cells. This will also cover impacts of the use of nanotechnology and nanomaterials in the various energy technologies. In-dept focus will also be on the formation of nanoparticles during combustion of bio-blended diesel, and the toxic effects of these new emission components.

The Government of Bangladesh (GOB) has set a goal to produce 6000 MW of electricity solely from solar Photovoltaic (PV) to ensure energy usage and sustainable development for every region by the year 2041. To meet this target, we have proposed a recently innovated floating PV (FPV) fed 1.4 MW capacity mini-grid system for the remote western coastal region of the country. Considering various practical load profiles, the paper contains an elaborate simulation of electrical characteristics for the modeled supply system. The simulation results show an excellent agreement with different levels of desired voltage, current, and power. Then, in-depth techno-economic and environmental analyses are presented to address the feasibility and benefit of the mini-grid. The optimum Cost of Energy (COE) from the generation facility is evaluated as 18.29 US cents which is consistent with the current tariff. We have estimated that 2500 households and 120 Electric-Vehicle (EV) scooters can save an emission of 228 and 466.56 metric tons, respectively, of Carbon Dioxide (CO2) per year. Finally, an experimental PV generation-based case study is demonstrated to emphasize the techno-economic impacts of the proposed mini-grid. For the electrical characteristics and techno-economic simulation, we have adopted MATLAB/Simulink and HOMER Pro software, respectively.

We fabricated Cu2ZnSnS4 (CZTS) thin films by electrochemically depositing precursor stacks on Mo-coated glass in a variety of orders: Cu/Sn/Cu/Zn, Cu/Zn/Cu/Sn, Zn/Cu/Sn/Cu, and Sn/Cu/Zn/Cu. Using Raman spectroscopy and X-ray diffraction, we found that for all stacking orders the annealed film was composed of a single CZTS phase with good crystallinity and strong (1 1 2) orientation. For the Cu/Sn/Cu/Zn stack, field-emission scanning electron microscopy revealed a homogeneous, compact surface morphology and large columnar grains. This stack also had an optical absorption coefficient of >104 cm−1 and an optical band gap of 1.51 eV. We fabricated a solar cell with the structure SLG substrate/Mo/Cu2ZnSnS4/CdS/i-ZnO Al:ZnO/Al, which achieved a conversion efficiency of 2.3%.

Determining the optimum tilt angle for PV system based power plants is crucial to be considered when fixing the PV systems. Although the optimum tilt angle is normally close to the latitude value of the location, lots of other factors affect this. So when designing a power plant, it is necessary to take these factors into consideration to maximize the output of those plants. The present paper reviews the main scientific concepts related to solar radiation, the models used to describe the solar radiation properties, and the methods of calculating the optimum tilt angle. The optimum tilt angle for northern Jordan and, as a case study, Jordan University of Science and Technology (JUST) Campus is then calculated by applying the appropriate methods and models. In addition to that, simulation software is used to calculate the optimum tilt angle and the yield of the power station. Other factors affecting the tilt angle of a PV array are reported and relevant recommendations are given. © 20...

The fact that traditional energy sources have limited reserves and have a negative impact on the environment increases the demand for renewable energy sources. Environmental, economic, and sustainability concerns have led researchers, investors, and policy makers to seek the potential of renewable energy sources. Suitable site selection for new-generation renewable resources is vital in large-scale projects. In this paper, geographic information systems and multicriteria decision-making (MCDM) methods were integrated to exploit and construct the best location for solar PV power plants in Kayseri, Turkey. Three main, twelve subcriteria, and their indicators related to the study area were determined. The rank-based (i.e., rank sum, rank reciprocal weights, and rank order centroid weights) and analytical hierarchical process (AHP) MCDM methods were used to determine the weights of the criteria. Thirty-three existing solar PV power plants were used to verify the success of MCDM methods. Four MCDM methods yielded effective results according to the proposed criteria, and most of the existing solar PV power plants match the convenient regions on the suitability map provided by geographic information systems-based rank reciprocal method. In addition, according to the experimental study, Sarız, Tomarza, and Incesu districts of Kayseri were the most suitable sites.

Low open circuit voltage (Voc) has been recognized as the number one problem in the current generation of Cu2 ZnSn(Se,S)4 (CZTSSe) solar cells. We report high light intensity and low temperature Suns-Voc measurement in high performance CZTSSe devices. The Suns-Voc curves exhibit bending at high light intensity, which points to several prospective Voc limiting mechanisms that could impact the Voc, even at 1 sun for lower performing samples. These Voc limiting mechanisms include low bulk conductivity (because of low hole density or low mobility), bulk or interface defects, including tail states, and a non-ohmic back contact for low carrier density CZTSSe. The non-ohmic back contact problem can be detected by Suns-Voc measurements with different monochromatic illuminations. These limiting factors may also contribute to an artificially lower Jsc-Voc diode ideality factor.

Despite Cu 2 ZnSnS 4 (CZTS) is a potential candidate for solar cell applications, so far, low efficiency values have been reported. In particular, for spray-deposited CZTS, efficiencies lower than 2% are commonly achieved. It is well known that one of the most important parameters governing solar cell performance is minority carrier diffusion length (L n). In this work, CZTS thin film solar cells with different composi-tional ratios are fabricated in order to study its impact on L n values. The L n parameter is calculated for sprayed-CZTS layers using external quantum efficiency measurements in conjunction with optical absorption coefficient versus wavelength measurements – for the first time. Values in the range of 0.11–0.17 lm are obtained emphasizing the need for improving sprayed-CZTS crystalline quality.

Installations of Solar Photovoltaic systems in distribution networks are increasing in very swift manner. These PV systems have both pros and cons associated with it. In terms of cons, it has power electronic devices which provides harmonics and thus affects the power quality of the grid by causing harmonic distortion. The aim of this study is the harmonic analysis of PV systems on grid. To emulate a realistic scenario a certain level of harmonics is also injected in the considered network through a dynamic load. Number of PV sources has increased and then the THD is analyzed for these cases. The scheme involves photovoltaic generation (PV) modules which are basically act as a DC current Source, which is connected to the grid through DC-DC converter and DC-AC Converter. Instead of current source inverter a voltage source inverter is utilized and the controlling technique is applied owing to control the voltage source inverter. MATLAB/SIMULINK tool has been used to simulate the considered grid connected PV system and to analyze it for the varying environmental conditions. Maximum power point tracking based on perturb & observe algorithm has been considered to analyze the system for maximum utilization under different irradiation and panel temperatures. These PV system provides harmonic distortion in the grid which affects the power quality of the grid as it is large in number. And with the no. of PV systems increasing rapidly it may become a bigger problem.

In electric power systems, integration of more Distributed Generators (DGs) in the network increase the short circuit level due to the short circuit current contribution of the DGs during faults. As compared to the synchronous and induction machine based generators, the inverter based generators, such as Photovoltaic (PV) solar systems, contributes lower fault current to the network due to the characteristics of PV panels and inverter operation. Although, each PV solar farm may contribute short currents as above, the total amount of fault current contribution may become unacceptably large for a feeder which has several PV systems connected. It is apprehended that short circuit current contributions from multiple solar systems in the distribution feeders may add up to levels that could be damaging to the circuit breakers. As a first step, adequate modeling of PV solar plants for predicting their short circuit contributions during network faults is essential. So far, the above fast faults detection techniques have been used for protection of network and DGs; and for unsymmetrical fault detection in fault current limiters (FCL). However these techniques have not been used to prevent any short circuit current contribution in excess of the rated or utility-acceptable current output of PV solar inverters. In this paper, a new fast detection module for short-circuit current detection has been discussed based on the rate of rise of current together with the current magnitude in a PV solar system based DG. There can be two control operations, as per the applicable grid code in that region, one of which is the disconnection of the PV inverter before the current exceeds the rated output current of the inverter. The second one discusses about transforming the PV inverter into a dynamic reactive power compensator STATCOM and provides grid support functions. A new concept of utilizing PV solar farms as STATCOM (PV-STATCOM) both during nighttime and daytime for different grid support functions was introduced in this paper.

Currently the use of energy from photovoltaic panels is a reality, and its extensive use will become extremely important in the research for solutions to energy and environmental problems. In this context, MPPT techniques are the most important part to extract the maximum power available. In this study, a DC-DC conversion system according to the boost topology has been designed. System tests were carried out outdoor at different solar radiation. First, the characteristic curve of the photovoltaic panel has been plotted, afterward the MPPT tracking system was connected. The controller communicates tracking data (current, voltage, duty cycle and power) at each step of the algorithm. Sometimes the algorithm deviates from the real maximum power point at first, making a false decision, but comes close thereafter. It is necessary to perform further investigations on this problem. An improvement of the used method is intended to take into account of all the constraints, so it would be possible to provide a simple and reliable system that tracks the maximum power point with minimum circuit and thus minimum consumption of energy.

The temperature of the photovoltaic module has an adverse effect on the performance of photovoltaic modules. The photovoltaic module converts a small portion of energy from solar radiations into electricity while the remaining energy wastes in the form of heat. In this study, water cooled PV/T system was analyzed to enhance the efficiency by absorbing the heat generated by the photovoltaic modules and allowing the photovoltaic module to work at comparatively low temperature. For this system, four photovoltaic modules of two different types were used. To investigate the cooling effect, two modules were modified by making ducts at their back surface having inlet and outlet manifolds for water flow. The measurements were taken with cooling and without cooling of photovoltaic modules. The temperature was measured at inlet, outlet and at different points at the back of Photovoltaic modules. It was found that there was a linear trend between the module efficiency and temperature. The average module temperature of c-Si and p-Si modules without cooling was 13.6% and 7.2% lower respectively than the same modules without cooling. As a result of temperature drop, the average module electrical efficiency of c-Si and p-Si was 13% and 6.2% higher respectively compared to the modules without cooling. Flowing water also gains useful heat from PV module so the resultant overall energy of the system was much higher.

This document proposes a photovoltaic (PV) based single-phase dynamic voltage restoration (DVR) device, it eliminates both sag and swell voltage and compensates for power. The proposed system requires a power source to compensate for the sag/swell voltage. This system has found a simple topology for the DVR that uses PV with two DC-DC boosts converters as the DC power source for the dynamic voltage conservator. The DC/DC boost converter powered by the PV generator is applied to increase the voltage to meet the DC bus voltage requirements of the single-branch voltage source inverter (VSI). This system uses renewable energy; saves energy accordingly and supplies power to critical/sensitive loads. The control method used in this work is a Sliding Mode Control (SMC) method and relies on a phase locked loop (PLL) used to control the active filter. The effectiveness of the suggested method is confirmed by the MATLAB/Simulink® simulation results and thelaboratorial prototype. These results show the capacity of the proposed DC link control.

Irrigation is a well established procedure on many farms and is practiced on various levels around the world. It allows diversification of crops, while increasing crop yields. However, typical irrigation systems consume a great amount of conventional energy through the use of electric motors and generators powered by fuel. Photovoltaic energy can find many applications in agriculture, providing electrical energy in various cases, particularly in areas without an electric grid. In this paper the description of reviews on a photovoltaic irrigation system, is presented. Photovoltaic water pumping system is one of the best alternative methods for irrigation. The variation of spatial and temporal distribution of available water for irrigation makes significant demand on water conservation techniques. Hence solar powered Automated Irrigation System provides a sustainable solution to enhance water use efficiency in the agricultural fields using renewable energy system removes workmanship t...

Solar photovoltaic (PV) technology has matured to become a technically viable large-scale source of sustainable energy. Understanding the rooftop PV potential is critical for utility planning, accommodating grid capacity, deploying financing schemes and formulating future adaptive energy policies. This paper merges the capabilities of geographic information systems and object-based image recognition to determine the available rooftop area for PV deployment in an example large-scale region in south eastern Ontario. An innovative five-step procedure has been developed for estimating total rooftop PV potential which involves geographical division of the region; sampling using the Feature Analyst extraction software; extrapolation using roof area-population relationships; reduction for shading, other uses and orientation; and conversion to power and energy outputs. A relationship across the region was found between roof area and population of 70.0 m2/capita ± 6.2%. For this region with appropriate roof tops covered with commercial solar cells the potential PV peak power output is 5.74 GW (157% of the region’s peak power demands) and the potential annual energy production is 6909 Gwh (5% of Ontario’s total annual demand). This suggests that 30% of Ontario’s demand can be met with province-wide rooftop PV deployment. This new understanding of roof area distribution and potential PV outputs has an immense significance to energy policy formulation in Ontario and the methodology developed here is transferable in other regions to assist in solar PV deployment.

In this research work silicon based solar panels were used to investigate the impact of series and parallel shading on the photovoltaic performance of inorganic solar panels. The results showed that voltage, current and power of the solar panels were reduced upon shading the series and parallel cells. This decrement was seen to be larger for the series shading compared to that of the parallel shading. This was attributed to the adverse effect of the series resistance of the shaded cells, which is acted as a bottleneck in front of the passage of current. This was not very effective in the parallel shading because current is readily capable to pass through the illuminated parallel cells and neglect the pathway of parallel shaded cells. From the results, it was concluded that the lower performance of solar panels due to shading effect is because of the change in the internal resistance of the panels. This situation is possible to occur during daily life use of solar panels as a result of the shading by clouds, dusts or trees. Hence, considerable investigation towards solving this problem is of great importance.

Modeling and predicting snow-related power loss is important to economic calculations, load management and system optimization for all scales of photovoltaic (PV) power plants. This paper describes a new method for measuring snow shedding from fielded modules and also describes the application of this method to a commercial scale PV power plant in Vermont with two subsystems , one with modules in portrait orientation and the other in landscape. The method relies on time-series images taken at 5 minute intervals to capture the dynamics of module-level snow accumulation and shedding. Module-level images extracted from the full-field view are binarized into snow and clear areas, allowing for the quantification of percentage snow coverage, estimation of resulting module power output, and temporal changes in snow coverage. Preliminary data from the Vermont case study suggests that framed modules in portrait orientation outperform their framed counterparts in landscape orientation by as much as 24% energy yield during a single shedding event. While these data reflect a single event, and do not capture snow shedding behavior across diverse temperature and other climatic conditions, the study nonetheless demonstrates that 1) module orientation and position in the array influence shedding patterns; 2) the start of power production and bypass diode activation differ for portrait and landscape module orientations at similar percentages and orientations of snow coverage; and 3) system design is an important factor in snow mitigation and increased system efficiency in snowy climates.

In the world, energy demand continues to grow incessantly. At the same time, there is a growing need to reduce CO 2 emissions, greenhouse effects and pollution in our cities. A viable solution consists in producing energy by exploiting renewable sources, such as solar energy. However, for the efficient use of this energy, accurate estimation methods are needed. Indeed, applications like Demand/Response require prediction tools to estimate the generation profiles of renewable energy sources. This paper presents an innovative methodology for short-term (e.g. 15 minutes) forecasting of Global Horizontal Solar Irradiance (GHI). The proposed methodology is based on a Non-linear Autoregressive neural network. This neural network has been trained and validated with a dataset consisting of solar radiation samples collected for four years by a real weather station. Then GHI forecast, the output of the neural network, is given as input to our Photovoltaic simulator to predict energy production in short-term time periods. Finally, experimental results for both GHI forecast and Photovoltaic energy prediction are presented and discussed.

The current research deals with renewable energy sources for the energy independence of Zakynthos Island in Greece. In order to define the most efficient renewable energy source, a multi-criteria analysis was used. The main criteria that were applied are the three pillars of sustainability, namely environment, society and economy. The aforementioned criteria were also subject to the DPSIR model of indicators, while a range of economic, environmental, social and technical sub-criteria were applied. The results, with regard to the delimitations set for the scope of the current research, indicate that the solar energy source systems (photovoltaics) are proved to be a more suitable alternative over a geothermal power station.

There are several photovoltaic (PV) performance models in the literature, but most of them either employ complex and tedious calculations or require additional measurements apart from datasheet information. In this paper, a new set of performance equations to evaluate the short circuit (SC) current, open circuit (OC) voltage and maximum power point (MPP) at any operating conditions is introduced. The proposed expressions are simple functions of the irradiance and temperature, while they are generally applicable to any crystalline PV module and require only datasheet information as input data. This is achieved by introducing new formulas to determine the irradiance and temperature coefficients that are not provided in the datasheet, thus avoiding empirical constants or additional measurements. The novelty of the performance equations is their solid theoretical background, as they are in excellent agreement with the single-diode PV model, combined with simple and easy application. The proposed PV model is validated and compared to other methods found in the literature through simulations in MATLAB and outdoor measurements on commercial PV modules.

In the present study three renewable power systems are proposed to select the most optimum one for powering an irrigation pumping system and a farmer's house in two different locations in Sinai, Egypt. Abu-Rudies in south Sinai and El-Arish in north Sinai are the two selected locations. The three suggested power systems are; standalone photovoltaic (PV) system, standalone wind system and standalone PV-wind hybrid system. HOGA (Hybrid Optimization by Genetic Algorithms) simulation software tool based on genetic algorithm (GA) is used for sizing, optimization and economical evaluation of three suggested renewable power systems. Optimization of the power system is based on the components sizing and the operational strategy. The calculated maximum amount of water required for irrigating ten acres of olive per day is 170 m 3. In terms of cost effectiveness, the optimal configurations are the hybrid PV-wind system and the standalone PV system for Abu-Rudies and El-Arish locations respectively. These systems are the most suitable than the others for the selected sites metrological data and the suggested electrical load.

Active power curtailment Reactive power capability A B S T R A C T The penetration of renewable distributed generations (DG) is recently being increased in distribution systems. Due to the intermittent nature of these generation units, several technical problems are expected based on the environmental conditions and load profiles, such as voltage rise and increasing losses. A traditional way to alleviate these technical problems is to oversize their interfacing inverters for releasing their capacities to inject/ absorb further reactive power. In the literature, the DG inverter is normally oversized by a certain percentage (e.g., 10%) for this purpose. In turn, an optimization-based method is proposed in this paper to calculate the optimal oversize of the interfaced inverter employed in various utility-owned DG types to regulate voltages and to reduce losses with minimum total costs. The proposed method considers the active power curtailment (APC) feature in the DG inverter and the transformer taps. Different control schemes of the interfaced inverter are considered and incorporated in the proposed optimization model. The simulation results demonstrate the effectiveness of the proposed method compared with existing methods.

With the increasing demand for solar energy as a renewable source has brought up new challenges in the field of energy. However, one of the main advantages of photovoltaic (PV) power generation technology is that it can be directly connected to the grid power generation system and meet the demand of increasing energy consumption. Large-scale PV grid-connected power generation system put forward new challenges on the stability and control of the power grid and the grid-tied photovoltaic system with an energy storage system. To overcome these problems, the PV grid-tied system consisted of 8 kW PV array with energy storage system is designed, and in this system, the battery components can be coupled with the power grid by AC or DC mode. In addition, the feasibility and flexibility of the maximum power point tracking (MPPT) charge controller are verified through the dynamic model built in the residential solar PV system. Through the feasibility verification of the model control mode and the strategy control, the grid-connected PV system combined with reserve battery storage can effectively improve the stability of the system and reduce the cost of power generation. To analyze the performance of the grid-tied system, some real-time simulations are performed with the help of the system advisor model (SAM) that ensures the satisfactory working of the designed PV grid-tied system. Keywords: Control strategy Depth of discharge Grid-tied system Insolation Inverter Lithium-ion battery Photovoltaic This is an open access article under the CC BY-SA license.

Given the need for decarbonization of the heating sector and the acute need of a propane replacement in the U.S. Upper Midwest, this study quantifies the techno-economic characteristics of sustainable heating electrification in isolated rural, residential buildings in cold climates without natural gas supply. Archetypal buildings are modeled under four levels of electrification. At each electrification level, a parametric solar photovoltaic (PV) sizing analysis is performed and the total life cycle cost, renewable fraction and greenhouse gas (GHG) emissions are calculated based on the primary energy supply for each building type. Cost optimal solutions are stress-tested with multi-dimensional sensitivity analyses. The results show that the total life cycle cost favors heating electrification in all cases and combining PV with heat pumps can reduce residential building GHG emissions by up to 50% immediately. This effect will grow over time, with over 90% reduction of building emissions if renewable energy targets are met. In using primary energy and emissions along with the multi-dimensional sensitivities, this study unique demonstrates the complex techno-economic interactions of PV and heat pumps. It is concluded that electrification is an economically viable decarbonization method for cold climates both now and in the future.