Rooftop Solar System Research Articles

Post-Processing of NWP Forecasts Using Kalman Filtering With Operational Constraints for Day-Ahead Solar Power Forecasting in Thailand

Solar power forecasting with a day-ahead horizon has played an important role in the operational planning of generating units in power system operations. We aim to develop a solar power forecasting model suitable for a tropical climate, using Thailand as a model, and hence present a linear recursive regression model as a post-processing step for reducing the errors obtained from the Weather Research and Forecasting (WRF) model. This model consists of submodels, each of which predicts the solar irradiance of a particular time of the day. By using a stepwise regression method, we found that WRF forecasts of irradiance, temperature, relative humidity, and the solar zenith angle were selected as highly relevant inputs of the model. The regression model coefficients are updated according to a Kalman filtering (KF) scheme so that the model can flexibly adapt to fluctuations in the solar irradiance. We then modify the KF update formula to accommodate the limitation in measurement availability at the time of executing the forecasts. The proposed KF formula can be generalized to find the optimal prediction given that the available measurements are mapped by an affine transformation. The obtained results using actual data from a solar rooftop system located in the central region of Thailand showed that the normalized root-mean-square error (NRMSE) of solar power prediction was about 12-13%, which was decreased from the NRMSE of the WRF model by 7-12% on average. This improvement was the best out of similar post-processing methods based on the model output statistics framework.

Deployment of rooftop solar photovoltaic electrification for residential buildings in Saudi Arabia’s industrial city: A study on public perception and acceptance in Yanbu Industrial City

Solar-based power generation is gaining attention worldwide as it is environment-friendly, and highly sustainable. Saudi Arabia is bestowed with vast solar energy availability. This should be the driving force for generating solar electricity to the optimal. However, the installation of solar photovoltaic is not as widespread as expected. As purposed-built cities emerged from the Kingdom's new economic development and renewable energy initiatives, they should lead the way for solar energy utilization. This paper aims to investigate the public perception and acceptance towards rooftop solar electrification in such cities in Saudi Arabia. Survey questionnaires were distributed to a sample population of Yanbu Industrial City to measure the perception, and readiness towards installing rooftop solar systems and gauge the populace's concerns. The outcome shows a variation of awareness levels, positive perception, and mix-readiness towards installation. The main barriers are the relatively low cost of fossil fuel-based electricity and the lack of clear incentives from authorities. Homeowners are more willing to invest in solar electricity for long term gain. Household income also has significant effects on the willingness for investment. The scenario analysis indicated that less than six years of payback could be achieved with the PV system which can be an attraction. https://dorl.net/dor/20.1001.1.13090127.2021.11.2.42.1

Techno-economic analysis and policy implications for promoting residential rooftop solar photovoltaics in Abu Dhabi, UAE

Although centralized solar systems have developed rapidly, decentralized solar systems are still unattractive to householders in Abu Dhabi due to technical and economic circumstances. This paper addresses this issue through a real-world case study examining the energy potential and economic performance of a rooftop solar system in two residential areas of Abu Dhabi. Then, following an analysis of the energy subsidy structure of Abu Dhabi, a new policy idea is discussed to mitigate the barriers to rooftop solar propagation. For a typical residence, a rooftop photovoltaic system would cover 11–20% of the annual electricity demand, indicating that the current net metering policy would be unattractive or useless to residents. The levelized cost of electricity of the considered system is around 0.05 USD per kWh, which is economically infeasible at the subsidized tariff for UAE nationals. However, at the higher tariff for expatriate residents, its internal rate of return ranges from 9.2 to 12.0%, implying a good possibility of success. This study proposes a new policy for government-led promotion of distributed solar systems through the redistribution of a portion of energy subsidies. This policy would expedite the proliferation of rooftop solar energy and reduce the expenditure for the government subsidy.

Solution to Economic Load Dispatch Problem of a Distributed Generating System using Pattern Search Algorithm

The solution of Economic Load Dispatch (ELD) problem is to allocate the total load demand to committed generating units with an objective to minimize the operating cost without violating the unit and system constraints. The growing power demand, atmospheric pollution and increased population makes it essential to invent a new power system with low pollution and transmission losses. The growing price and limited availability of fossil fuels makes installation of conventional power plants uneconomical. Installation of non-conventional power plants like roof top solar plants is essential to meet the increased load demand and environmental pollution standards. The output of roof top solar systems is intermittent because it depend on atmospheric conditions. To find a solution to economic load dispatch of distributed generation system (ELDDGS) with roof top solar plants is a difficult problem because of its intermittent and scattered nature. This paper will explain a solution to economic load dispatch of a distributed generation system using pattern search algorithm.

Designing and Evaluating the Solar Roof Top Plant Interconnectivity System for the Residential Buildings

To accomplish the installation of capacity target Solar Roof Top Plants set by Ministry of New Renewable Energy (MNRE) is an absolute essential requirement of installing the Solar Roof Top Plants in India. A salient and efficient system, pre-estimation and anticipation is indispensable. A 91.8 KW system of Solar Roof Top Plant within the 14 Residential Building's is achieved by the using the cloud based Helioscope software. It is designed and located with the help of this software. Increasing the reliability of system by establishing the Interconnectivity.For the better and efficient energy flow a Hybrid Inverter and a Charge Controller is used. Battery Management System (BMS) is used for smart and efficient storage system. Lithium Ferro Phosphate (LFP) batteries are used to reduce the thermal run-away in batteries. Usage of Bi-directional meter for recording the energy flow bidirectionally. Effectuating the Sub-Metering system for realizing the energy consumption and production of the Residential Solar Roof Top Plant. The performance ratio, annual production and potential energy yield per installed capacity (kWh/kWp) are calculated by using the Helioscope software. Cost Analysis of the system is done to estimated the investment, power production and consumption. Calculated the savings amount, Internal Rate of Return and observed the payback period in 11.965 (i.e. approximately 12 years).

A framework for the performance evaluation of household rooftop solar battery systems

Grid integration of rooftop solar systems are increasing at a rapid pace throughout the world. Battery energy storage has become integral part of rooftop solar systems, as it provides a mean to best utilize the solar energy. Since, the battery performance degrades in the course of its utilization based on the nature of use (charging, discharging pattern and temperature) and it is one of the most expensive component of a rooftop solar system, its charging and discharging operation is required to be regulated in a judicial manner. Therefore, it is imperative to study the performance of rooftop solar batteries based on its actual charging and discharging profile that reflects the intermittency in solar irradiation and households electricity consumption pattern. This paper presents a generic methodology using Monte-Carlo simulation approach to evaluate performance of solar batteries considering uncertainties in solar and energy consumption pattern. The efficacy of the proposed approach has been verified using real solar generation and energy consumption data of Sydney CBD. The results show a clear insight to the performance of rooftop residential solar batteries over the span of its usage.

Benefits and costs of a utility-ownership business model for residential rooftop solar photovoltaics

The rapid growth of rooftop solar photovoltaic systems can pose a number of financial challenges for electric utility shareholders and their customers. One potential pathway to resolving these perceived challenges involves allowing utilities to own and operate rooftop solar systems. However, the financial benefits and costs of this business model are not well understood. Here we model the financial performance of a large-scale utility-owned residential rooftop solar programme. Over a 20 yr period, the programme increases shareholder earnings by 2–5% relative to a no-solar scenario, compared to a 2% earnings loss when an equivalent amount of rooftop solar is instead owned by non-utility parties. Such a programme could therefore be attractive from the perspective of utility investors. The impacts on utility customers, however, are more mixed, with average bills of non-solar customers increasing by 1–3% compared to the no-solar scenario, similar to the 2% increase under traditional, non-utility-ownership structures. Utility ownership of rooftop solar can potentially align utility financial interests with solar photovoltaic uptake, but the economic implications are not well understood. Now, G. Barbose and A. Satchwell evaluate the potential benefits of this model for utility shareholders and customers and show viability.

Electricity Generation Through Water Supply Pipes in High Rise Buildings

Day by day, with the improved per capita demand and increasing population, energy requirements are increasing globally. Big organizations are trying to develop zero energy establishments by using solar rooftop systems and by following green building norms. This paper proposes to utilize the kinetic energy of water falling in high-rise buildings for the generation of electricity. This study proposes the idea of extracting electric power from falling water in high-rise buildings. A 15[Formula: see text]m high building is considered for the study, having sufficient water head to run a micro-hydro turbine. Hydraulic turbines are stationed at each storey of the building, which employs the water energy for the generation of electricity. Analytically, the suggested setup is commercially propitious for several major cities of the country. The economic review of the suggested setup is discussed for possible commercialization of the idea.

Distributional disparities in residential rooftop solar potential and penetration in four cities in the United States

Single-family residential rooftop solar adoption in the United States has not occurred equitably across the country, nor across socioeconomic and demographic groups. In response, state and local governments have developed solar equity programs, primarily focused on increasing adoption by low- and moderate-income (LMI) households. This study merged national datasets that estimate rooftop solar potential, the distribution of rooftop solar systems, and census tract- level socioeconomic and demographic characteristics to answer three questions. First, how are spatial distributions of rooftop potential and penetration similar and different across cities? Second, how is rooftop penetration distributed across non-LMI and LMI communities in different cities? Third, how do the relationships between rooftop penetration and local socioeconomic and demographic characteristics, identified as barriers to solar adoption, differ? Using GIS, bivariate and multivariate analyses, these questions were examined in four US cities – Riverside and San Bernardino, California, Washington, DC, and Chicago, Illinois – to understand both universal and distinct local manifestations. Findings include: higher rooftop potential existed in some LMI communities; higher rooftop potential did not necessarily translate to higher rooftop penetration, especially if higher potential was in LMI communities; and beyond income, other socioeconomic and demographic characteristics such as race/ethnicity, limited English proficiency, age of housing stock, and internet access were associated with rooftop penetration. While there remains great potential for expanding rooftop solar to LMI households and communities, understanding the local dynamics of solar potential and penetration may inform better policy development and implementation.

Optimal Sizing, Scheduling and Building Structure Strategies for a Risk-averse Isolated Hybrid Energy System in Kish Island

High costs of the conventional energy systems’ operation are one of the main challenges for isolated energy systems. Problems and costs of the fuel transferring to the islands for using in the diesel generator systems is another challenge for the operators. In this paper, a solar-based hybrid energy system (SHES) is proposed to satisfy the demands of an isolated industrial complex in Kish Island, an island in the south of Iran, in an optimal way. The proposed SHES contains various energy systems such as diesel generator, energy storage and rooftop solar power generation systems to provide demands of the isolated industrial complex's different users. This work tries to solve the optimization problem in a more optimal way by both energy saving arrangements and optimal sizing and operation of energy components. The load's consumption of the proposed isolated energy system is reduced optimally by using the construction operations related to the buildings’ walls and windows insulation. After that, the optimal sizing and operation of the energy components are applied to the isolated energy system to satisfy the reduced demands. In other words, insulating walls and windows, with a low investment cost, will reduce the amount of the proposed isolated energy system's load and the load reduction makes a more cost reduction in the investment cost of energy generation systems. An Information gap decision theory-based (IGDT-based) optimization method is applied to the proposed model to find a robust solution against load uncertainty for the proposed problem. Finally, the proposed method is implemented to a comprehensive test case to demonstrate the practicability and applicability of the proposed approach.

Adoption of grid-connected solar rooftop systems in the state of Jammu and Kashmir: A stakeholder analysis.

Renewable energy is being seen as a transformative solution to meet energy as well as economic challenges at national as well as at a global level. The Government of India has expressed its intent to achieve 100 GW of solar capacity in the country by 2020. However, one such state that lags in harnessing and achieving the solar targets is the state of Jammu and Kashmir despite having the second highest potential of solar energy. Jammu and Kashmir is a power deficit state though it has one of the best potentials in solar energy. Solar rooftop PV systems can solve most of the problems regarding power deficit, but yet people are naïve about solar rooftop PV systems. The purpose of this study is to perform stakeholder analysis to investigate the perceptions of the groups/individuals regarding grid connected solar rooftop PV systems. They have a critical impact on the result of the study as they provide fundamental data on the political, social and economic scenario of any study area. The findings from the investigation underscores that all the projects and programs related to the adoption of a solar rooftop system should concentrate on building awareness.

Characterising Seasonality of Solar Radiation and Solar Farm Output

With the recent rapid increase in the use of roof top photovoltaic solar systems worldwide, and also, more recently, the dramatic escalation in building grid connected solar farms, especially in Australia, the need for more accurate methods of very short-term forecasting has become a focus of research. The International Energy Agency Tasks 46 and 16 have brought together groups of experts to further this research. In Australia, the Australian Renewable Energy Agency is funding consortia to improve the five minute forecasting of solar farm output, as this is the time scale of the electricity market. The first step in forecasting of either solar radiation or output from solar farms requires the representation of the inherent seasonality. One can characterise the seasonality in climate variables by using either a multiplicative or additive modelling approach. The multiplicative approach with respect to solar radiation can be done by calculating the clearness index, or alternatively estimating the clear sky index. The clearness index is defined as the division of the global solar radiation by the extraterrestrial radiation, a quantity determined only via astronomical formulae. To form the clear sky index one divides the global radiation by a clear sky model. For additive de-seasoning, one subtracts some form of a mean function from the solar radiation. That function could be simply the long term average at the time steps involved, or more formally the addition of terms involving a basis of the function space. An appropriate way to perform this operation is by using a Fourier series set of basis functions. This article will show that for various reasons the additive approach is superior. Also, the differences between the representation for solar energy versus solar farm output will be demonstrated. Finally, there is a short description of the subsequent steps in short-term forecasting.

On the benefits of behind-the-meter rooftop solar and energy storage: The importance of retail rate design

Abstract We investigate the impact of retail rate design on the investment incentives, avoided utility costs, and cost-shifting concerns associated with rooftop solar plus battery storage systems that are located behind-the-meter. To illustrate these interactions, we consider recently proposed changes to California's time-of-use pricing policy for commercial and industrial consumers which shifts on-peak prices from midday to the constrained evening hours. We find that these rate adjustments reduce cost-shifting concerns across consumers considerably, but also decreases solar PV investment and has an ambiguous effect on storage investment. We demonstrate that storage reduces utility costs, but the magnitude of this effect varies critically with the prevailing retail rate structure. Importantly, we show that a shift in the on-peak period to the constrained evening hours does not always elevate the avoided cost associated with a battery system when demand charges are imposed on a consumer's private maximum demand. We illustrate that this issue can be alleviated by imposing demand charges on consumption that arises in system-constrained hours. We find that while storage reduces the utility's costs, it can also increase cost-shifting concerns. These findings demonstrate the potential trade-offs between maximizing avoided costs and minimizing cost-shifting concerns under commonly employed retail rate structures.

Smart Meter Data to Optimize Combined Roof-Top Solar and Battery Systems Using a Stochastic Mixed Integer Programming Model

This paper presents the design and results of a model that uses household smart meter data, electric vehicle (EV) travel load and charging options, and multiple solar resource profiles, to make decisions on optimal combinations of photovoltaics (PV), battery energy storage systems (BESS) and EV charging strategies. The least-cost planning model is formulated as a stochastic mixed integer programming (MIP) problem that makes first stage decisions on PV/BESS investments, and recourse decisions on purchase/sell from/to the grid to minimize expected household electricity costs. The model undertakes a customer-centric optimization taking into consideration net metering policy, time-of-use grid pricing, and uncertainties around inter-annual variability of solar irradiance. The model adds to the existing literature in terms of stochastic representation of inter-annual variability of solar irradiance, together with BESS capacity optimization, and EV charging mode selection. Three case studies are presented: two for a residential house with and without EV load, and a third for a larger community facility. Results from the model for the first residential house case study are compared with commercially available software to show the impacts of an accurate load profile and different policy parameters. The stochastic feature of the model proves useful in understanding the impact of variability in solar resource profiles on PV sizing. Finally, simulations of alternative EV travel patterns and tariff policies that discourage charging during the evening peak show the efficacy of `super off-peak' pricing being introduced in the state of Maryland.

Economic Feasibility Analysis of Rooftop Solar Power Plant Design with Household-Scale On-Grid System in Semarang City

The electricity demand share in the household sector will increase from 49% in 2018 to 58% in 2050 as predicted. This issue is particularly caused by the household growth number which may increase from 67 million in 2018 to approximately 80 million in 2050. For the household customer number are increasing, utilizing rooftop as the base of solar power plants can be an effective and efficient solution. In addition, the government regulation supports the acceleration and development of new and renewable energy. This research aims to analyze the technical economic feasibility of rooftop solar power plant system with a household-scale on-grid system in Semarang City. Through PVSyst 6.43 and RetScreen software also equipped with several primary components, this household-scale rooftop solar power plant investment plan is estimated to have an average revenue return estimated in 10 years later.

Analysis of 1KW Solar Rooftop System by Using PYSyst

The act of a photovoltaic system depends on the geographical location and type of PV modules implemented. PV systems are beneficial in areas having a moral amount of incident solar radiation. Pune gets an annual average solar radiation of about 5.4 kWh/m2 a day. In this paper 1KW, the photovoltaic system is designed and simulated using PVSyst software for Pune, Maharashtra, India using measured data of the location. The total amount of energy generated by the system and various losses occurring in the system is analyzed and presented Performance ratio of the system over the whole year is estimated as which shows that generation of electricity from the PV system is a variable option for Pune to supplement the increasing energy needs.

Microgeneration of Electricity Using a Solar Photovoltaic System in Ireland

Microgeneration of electricity using solar photovoltaic (PV) systems is a sustainable form of renewable energy, however uptake in Ireland remains very low. The aim of this study is to assess the potential of the community-based roof top solar PV microgeneration system to supply electricity to the grid, and to explore a crowd funding mechanism for community ownership of microgeneration projects. A modelled microgeneration project was developed: the electricity load profiles of 68 residential units were estimated; a community-based roof top solar PV system was designed; an electricity network model, based on a real network supplying a town and its surrounding areas, was created; and power flow analysis on the electrical network for system peak and minimum loads was carried out. The embodied energy, energy payback time, GHG payback time, carbon credits and financial cost relating to the proposed solar PV system were calculated. Different crowdfunding models were assessed. Results show the deployment of community solar PV system projects have significant potential to reduce the peak demand, smooth the load profile, assist in the voltage regulation and reduce electrical losses and deliver cost savings to distribution system operator and the consumer.

A Multilevel Distributed Hybrid Control Scheme for Islanded DC Microgrids

This paper proposes a multilevel hybrid control scheme, including grid control and node control, for an islanded 48-V solar photovoltaic-based low voltage dc microgrid that aims to overcome the drawbacks of centralized and decentralized control schemes. The analyzed microgrid includes a 35-kW rooftop solar system as the main power source at bus-1 with battery storage, 5-kW hybrid energy storage system (Vanadium Redox flow battery with super capacitor) at bus-2, and variable loads such as electrical vehicles at bus-3. In the case of a central failure, the proposed hybrid control scheme is capable of seamlessly switching between high bandwidth communication and low bandwidth communication channels of communications to implement a distributed control scheme. The central supervisory controller is responsible for updation of grid characteristics and sending/receiving information to/from local node controllers, which are responsible for bus voltage regulation and energy management. The control hierarchy features optimized and safe operation (charge and discharge) of storage devices in dc microgrids. The paper also demonstrates the application of battery-supercapacitor systems to absorb system transients during load changes. The simulation showcases the continuous flow of information and decision processes via each level of control while simultaneously taking into consideration the constraints of each subsystem. The scheme has been simulated in MATLAB/Simulink environment for various case studies to evaluate system robustness. Further, the proposed scheme has been tested experimentally with its prototype and its results are explored.

Performance and Economic Evaluation of Solar Rooftop Systems in Different Regions of Thailand

Solar rooftop systems in the residential sector have been rapidly increased in the term of installed capacity. There are various factors, such as climate, temperature, and solar radiation, that have effects on solar power generation efficiency. This paper presents a performance assessment of a solar system installed on the rooftop of residence in different regions of Thailand by using PSIM simulation. Solar rooftop installation comparison in different regions is carried out to evaluate the suitable location. In addition, three types of solar panels are used in research: monocrystalline, polycrystalline, and thin-film. The electrical parameters of real power and energy generated from the systems are investigated and analyzed. Furthermore, the economic evaluation of different solar rooftop system sizes using the monocrystalline module is investigated by using economic indicators of discounted payback period (DPP), net present value (NPV), internal rate of return (IRR), and profitability index (PI). Results show that the central region of Thailand is a suitable place for installing solar rooftop in terms of solar radiation, and the temperature has more solar power generation capacity than the other regions. The monocrystalline and polycrystalline solar panels can generate maximum power close to each other. All solar rooftop sizes with the Feed-in Tariff (FiT) scheme give the same DPP of 6.1 years, IRR of 15%, and PI of 2.57 which are better than the cases without the FiT scheme. However, a large-scale installation of solar rooftop systems can receive more electrical energy produced from the solar rooftop systems. As a result, the larger solar rooftop system sizes can achieve better economic satisfaction.

Implementation of power inverter on grid connected photovoltaic generator system

The issuance of ESDM (ministry of energy and mineral resources) regulation number 49 of 2018 concerning the use of a rooftop solar power generation system by consumers of PT PLN (Persero). It is encouraging to conduct research on one method of generating electricity using solar panels. The voltage generated in the generation process using solar panels is a direct voltage (DC) and requires an inverter as a voltage converter to be an alternating voltage (AC) which is the daily consumption of Indonesian people. This research aims to develop the use of renewable energy using an inverter. This inverter uses batteries as a source of voltage, Arduino as a source of SPWM waves, and MOSFETs are arranged in a full-bridge configuration to convert 12V DC electricity into 12VAC which will then be filtered using a low-pass filter to pass a 50 Hz frequency and then increase the voltage using a transformer to 220Vmax / 155 Vrms. The result of designing this research is that the inverter is able to produce a sinusoidal wave output 220 Vmax with a frequency of 50 Hz. With the output signal approaching the sinusoidal signal purely from the filter output, the power loss from the use of the transformer causes the power output from the inverter to be not optimal.