Quantifying System-Level Benefits from Distributed Solar and Energy Storage

The growth in the adoption of solar photovoltaic (PV) power generation systems has been accelerating around the world, contributing to the debate about the future of policy and regulation in a high distributed energy resources future. Thailand is one of the leaders in solar investment in Southeast Asia. It has recently shifted its policy framework from subsidizing power export through feed-in tariffs toward a policy that is focused on supporting self-consumption of PV electricity. There are three possible forms of self-consumption support scheme: net metering, net billing, and self-consumption only. Net metering and net billing are electricity policies to assign compensation to excess electricity generated from the prosumers? sources, particular in rooftop solar PV system. The design elements on new self-consumption scheme from perspectives of various stakeholders together with the assessment of economic feasibility of rooftop PV system under self-consumption schemes can help to ensure successful implementation of the policy. It is important to analyze the possible impacts of rooftop PV system on distribution network system. This dissertation consists of three main components: economic feasibility analysis, technical analysis, and stakeholders? perspectives analysis. First, this study assesses the economic feasibility of residential and commercial sectors on rooftop solar PV systems under Thailand?s self-consumption scheme, net metering with rolling credit and buyback scheme, and net billing with real-time buyback scheme. These three schemes are compared using 3 indicators: Net Present Values (NPV), Payback Period (PB), and Internal Rate of Return (IRR) to assess the feasibility of rooftop solar PV investment for consumers. To supplement the understanding of selected schemes, this research assesses the technical factors that support or hinder the implementation of solar PV rooftop by reviewing Thailand?s grid code and meter requirement of rooftop solar PV installation. Third, this study investigates the perspectives of stakeholders on the detailed design options of self-consumption schemes for supporting rooftop solar PV system installation. When combined the outcomes of stakeholder?s perspectives, the result also shows that most of stakeholder groups prefer a strong desire to compensate for excess generation from rooftop PV system in the form of net metering. This finding corresponds to the economic feasibility analysis, which indicate that net metering with rolling credit and buyback is economically feasible for both residential and commercial sectors. Finally, this dissertation suggests policy recommendations for each group of stakeholders in order to increase their understanding on how to contribute to a sustainable scheme to scale up rooftop solar PV installation for both residential and commercial customers in Thailand.

The installed capacity of grid-tied photovoltaic (PV) systems around the globe is increasing rapidly due to the need for clean, sustainable and fuel independent energy. The PV technology is already a major part of the energy mix in many developed and developing countries. The electricity generated from these systems heavily depends on the prevailing weather conditions and is directly related to the available solar irradiance. Therefore, the electricity injected into the grid from these systems is intermittent reducing the utility of that generated power. Any sudden irradiance changes, due to passing clouds, rain, dust storms, etc., directly affect the power response of solar systems, compromising the security of electricity supply and resulting in the need for operating reserves to stabilize the supply. The further deployment of grid connected PV systems will benefit greatly by developing the methodology to systematically study and analyse the variability and quantity of the power produced by installed PV...

As the cost of solar photovoltaic (PV) falls, their potential for transforming modern electricity generation increases. Solar PV provides a simpler way of producing clean and affordable energy, which makes it an attractive investment. Great investments in solar PV have occurred in industrialized countries, but government efforts to promote this technology have not been effective in nonindustrialized countries. Despite this, some of these countries may have a high solar PV potential, such as Colombia, where policies to encourage solar PV are only just starting to take place. Therefore, this paper proposes a simulation model to assess different policies—feed-in tariff, net metering, and capital subsidy—to promote solar PV investments in the Colombian residential sector. Policies are assessed considering the criteria of efficiency and effectiveness. Simulation results suggest that (i) net metering is the most efficient policy with a cost indicator of 20,298 USD/MW; (ii) feed-in tariff is the most effective policy as it reaches the highest level of avoided CO2 emissions—4,792,823 million tons of CO2—and a meaningful PV installed capacity of 7522 MW; (iii) capital subsidy is the least efficient policy as it has the highest cost indicator of 509,616 USD/MW.

Installations of solar photovoltaic (PV) systems have been growing at a rapid pace in recent years. In 2009, approximately 7,500 megawatts (MW) of PV were installed globally, up from approximately 6,000 MW in 2008, consisting primarily of grid-connected applications. With 335 MW of grid-connected PV capacity added in 2009, the United States was the world's fourth largest PV market in 2009, behind Germany, Italy, and Japan. The market for PV in the United States is driven by national, state, and local government incentives, including up-front cash rebates, production-based incentives, requirements that electricity suppliers purchase a certain amount of solar energy, and federal and state tax benefits. These programs are, in part, motivated by the popular appeal of solar energy, and by the positive attributes of PV - modest environmental impacts, avoidance of fuel price risks, coincidence with peak electrical demand, and the possible deployment of PV at the point of use. Given the relatively high cost of PV, however, a key goal of these policies is to encourage cost reductions over time. Therefore, as policy incentives have become more significant and as PV deployment has accelerated, so too has the desire to track the installed cost of PV systems over time, by system characteristics, by system location, and by component. Despite the significant year-on-year growth, however, the share of global and U.S. electricity supply met with PV remains small, and annual PV additions are currently modest in the context of the overall electric system. To address this need, Lawrence Berkeley National Laboratory initiated a report series focused on describing trends in the installed cost of grid-connected PV systems in the United States. The present report, the third in the series, describes installed cost trends from 1998 through 2009, and provides preliminary cost data for systems installed in 2010. The analysis is based on project-level cost data from approximately 78,000 residential and non-residential PV systems in the U.S., all of which are installed at end-use customer facilities (herein referred to as 'customer-sited' systems). The combined capacity of systems in the data sample totals 874 MW, equal to 70% of all grid-connected PV capacity installed in the United States through 2009 and representing one of the most comprehensive sources of installed PV cost data for the U.S. The report also briefly compares recent PV installed costs in the United States to those in Germany and Japan. Finally, it should be noted that the analysis presented here focuses on descriptive trends in the underlying data, serving primarily to summarize the data in tabular and graphical form; later analysis may explore some of these trends with more-sophisticated statistical techniques. The report begins with a summary of the data collection methodology and resultant dataset (Section 2). The primary findings of the analysis are presented in Section 3, which describes trends in installed costs prior to receipt of any financial incentives: over time and by system size, component, state, system ownership type (customer-owned vs. third party-owned), host customer segment (residential vs. commercial vs. public-sector vs. non-profit), application (new construction vs. retrofit), and technology type (building-integrated vs. rack-mounted, crystalline silicon vs. thin-film, and tracking vs. fixed-axis). Section 4 presents additional findings related to trends in PV incentive levels over time and among states (focusing specifically on state and utility incentive programs as well as state and federal tax credits), and trends in the net installed cost paid by system owners after receipt of such incentives. Brief conclusions are offered in the final section, and several appendices provide additional details on the analysis methodology and additional tabular summaries of the data.

Long term supporting schemes for photovoltaic (PV) system installation have led to accommodating large numbers of PV systems within load pockets in distribution grids. High penetrations of PV systems can cause new technical challenges, such as voltage rise due to reverse power flow during light load and high PV generation conditions. Therefore, new strategies are required to address the associated challenges. Moreover, due to these changes in distribution grids, a different response behavior of the distribution grid on the transmission side can be expected. Hence, a new equivalent model of distribution grids with high penetration of PV systems is needed to be addressed for future power system studies. The thesis contributions lie in three parts. The first part of the thesis copes with the PV modelling. A non-proprietary PV model of a three-phase, single stage PV system is developed in PSCAD/EMTDC and PowerFactory. Three different reactive power regulation strategies are incorporated into the models and their behavior are investigated in both simulation platforms using a distribution system with PV systems. In the second part of the thesis, the voltage rise problem is remedied by use of reactive power. On the other hand, considering large numbers of PV systems in grids, unnecessary reactive power consumption by PV systems first increases total line losses, and second it may also jeopardize the stability of the network in the case of contingencies in conventional power plants, which supply reactive power. Thus, this thesis investigates and develops the novel schemes to reduce reactive power flows while still keeping voltage within designated limits via three different approaches: 1. decentralized voltage control to the pre-defined set-points 2. developing a coordinated active power dependent (APD) voltage regulation Q(P) using local signals 3. developing a multi-objective coordinated droop-based voltage (DBV) regulation Q(V) using local signals In the third part of the thesis, furthermore, a gray-box load modeling is used to develop a new static equivalent model of a complex distribution grid with large numbers of PV systems embedded with voltage support schemes. In the proposed model, variations of voltage at the connection point simulate variations of the model’s active and reactive power. This model can simply be integrated into load-flow programs and replace the complex distribution grid, while still keeping the overall accuracy high. The thesis results, in conclusion, demonstrate: i) using rms-based simulations in PowerFactory can provide us with quite similar results using the time domain instantaneous values in PSCAD platform; ii) decentralized voltage control to specific setpoints through the PV systems in the distribution grid is fundamentally impossible due to the high level voltage control interaction and directionality among the PV systems; iii) the proposed APD method can regulate the voltage under the steady-state voltage limit and consume less total reactive power in contrast to the standard characteristic Cosf (P) proposed by German Grid Codes; iv) the proposed optimized DBV method can directly address voltage and successfully regulate it to the upper steady-state voltage limit by causing minimum reactive power consumption as well as line losses; v) it is beneficial to address PV systems as a separate entity in the equivalencing of distribution grids with high density of PV systems.

Solar photovoltaic (PV) panels are projected to become the largest contributor of clean electricity generation worldwide. Maintenance and cleaning strategies are crucial for optimizing solar PV operations, ensuring a satisfactory economic return of investment. Nanocoating may have potential for optimizing PV operations; however, there is insufficient scientific evidence that supports this idea. Therefore, this study aims to investigate the effectiveness of nanocoating on the performance of solar photovoltaic (PV) panels installed in Al Seeb, Oman. A further study was also carried out to observe the influence of coating layers on the performance of PV panels. One SiO2 nanocoated solar panel, another regularly cleaned PV panel, and a reference uncleaned panel were used to carry out the study. The site of the study was treeless and sandy, with a hot and dry climate. A data logger was connected to the solar PV panel and glass panel to record the resulting voltage, current, temperature, and solar radiation. It was observed that nanocoated PV panels outperformed both regular PV panels and uncleaned PV panels. Nanocoated PV panels demonstrated an average efficiency of 21.6%, showing a 31.7% improvement over uncleaned panels and a 9.6% improvement over regularly cleaned panels. Although nanocoating displayed high efficiency, regular cleaning also contributes positively. Furthermore, even though nanocoated PV panels outperformed the other two panels, it is important to note that the performance difference between the regular cleaned PV panels and the nanocoated PV panels was small. This indicates that regular cleaning strategies and nanocoating can further contribute to maintaining a more efficient solar PV system. Coating in many layers was also observed to influence the performance of PV panels insignificantly, mainly the fourth layer coating appeared to have formed sufficient mass to retain heat.

Microgrid system sizing and aggregation of distributed energy resources for wholesale market participation

Development of fire safety best practices for rooftops grid-connected photovoltaic (PV) systems installation using systematic review methodology

While the majority of electricity generated in the United States comes from fossil fuels such as coal and natural gas, a comparatively small amount comes from renewable sources such as solar and hydropower. As global environmental issues become a greater concern, more generation may need to come from renewable sources. One often-mentioned alternative is residential solar photovoltaic (PV) systems, which could be an especially attractive source of energy in the southwestern United States, where high amounts of solar radiation are available. In this paper, we compare the life-cycle costs of current solar photovoltaic technology in Arizona versus New York to highlight the relevant issues related to the economic and environmental renewable energy decision-making process. We find that solar PV systems alone are currently inferior to grid electricity across a wide range of scenarios, including prospective technology improvements. Net metering with PV systems, where customers sell solar electricity to the grid and buy back their demand, may be competitive given real-time electricity pricing. Using PV systems in remote systems looks to be a viable alternative.

<span lang="EN-US">The Energy and <span>natural resources ministry (KeTSA) of Malaysia has introduced the net energy metering (NEM) 3.0, which provides an opportunity for consumers to install solar photovoltaic (PV) systems to reduce electricity bills. The NEM 3.0 introduces three new initiatives that offer 500 MW quota from 2021 till 2023. NEM has been implemented since 2016, replacing the feed-in tariff (FiT) strategy by promoting the users to utilize the generated energy in the first place before selling any surplus to the utility. As in the FiT strategy, users can only sell the generated energy at a fixed rate without utilizing it. This paper presents the comparative study between NEM and FiT for 496 kWp solar photovoltaic system in UiTM Segamat, Johor in the perspective of economy and energy practice based on the simulation result of MATLAB/Simulink software</span>.</span>

Integration of solar photovoltaic system with energy storage system such as batteries is always seen as a better way to utilize the available output power from renewable energies. Considering continuous sustainability using batteries, charging – discharging the batteries to store the excessive output from solar photovoltaic panels is an important aspect to be considered. Therefore, this paper proposes hierarchical switching charging – discharging system for continuous sustainability integrated together with solar photovoltaic system. The hierarchical switching charging – discharging system comprises of the hardware and software development. The typical design of the hardware structure is setup to integrate the consumable renewable energy source to the battery energy storage system and the load. The hierarchical charging – discharging strategy which is the embedded software is proposed to allow the charging – discharging control and switching between the dual and more battery energy storages. The hardware research and development results shows that the proposed strategy have effectively justify the developed system’s performances.

This study investigates the techno-economic feasibility of installing a 3-kilowatt-peak (kWp) photovoltaic (PV) system in Kathmandu, Nepal. The study also analyses the importance of scaling up the share of solar energy to contribute to the country's overall energy generation mix. The technical viability of the designed PV system is assessed using PVsyst and Meteonorm simulation software. The performance indicators adopted in our study are the electric energy output, performance ratio, and the economic returns including the levelised cost and the net present value of energy production. The key parameters used in simulations are site-specific meteorological data, solar irradiance, PV capacity factor, and the price of electricity. The achieved PV system efficiency and the performance ratio are 17% and 84%, respectively. The demand–supply gap has been estimated assuming the load profile of a typical household in Kathmandu under the enhanced use of electric appliances. Our results show that the 3-kWp PV system can generate 100% of electricity consumed by a typical residential household in Kathmandu. The calculated levelised cost of energy for the PV system considered is 0.06 $/kWh, and the corresponding rate of investment is 87%. The payback period is estimated to be 8.6 years. The installation of the designed solar PV system could save 10.33 tons of CO2 emission over its lifetime. Overall, the PV systems with 3 kWp capacity appear to be a viable solution to secure a sufficient amount of electricity for most households in Kathmandu city.

Solar photovoltaic (PV) technology has the versatility and flexibility for developing off-grid electricity system for different regions, especially in remote rural areas. While conventionally straight forward designs were used to set up off-grid PV-based system in many areas for wide range of applications, it is now possible to adapt a smart design approach for the off-grid solar PV hybrid system. A range of off-grid system configurations are possible, depending upon load requirements and their electrical properties as well as on site-specific available energy resources. The overall goal of the off-gird system design should be such that it should provide maximum efficiency, reliability and flexibility at an affordable price. In this chapter, three basic PV systems, i.e. stand-alone, grid-connected and hybrid systems, are briefly described. These systems consider different load profiles and available solar radiations. A systematic approach has then been presented regarding sizing and designing of these systems. Guidelines for selection of PV components and system sizing are provided. Battery energy storage is the important component in the off-grid solar PV system. Due to load and PV output variations, battery energy storage is going to have frequent charging and discharging. So the type of battery used in a PV system is not the same as in an automobile application. Detailed guidelines for selection of battery are therefore also provided. At present, most of the world-wide PV systems are operating at maximum power points and not contributing effectively towards the energy management in the network. Unless properly managed and controlled, large-scale deployment of PV generators in off-grid system may create problems such as voltage fluctuations, frequency deviations, power quality problems in the network, changes in fault currents and protections settings, and congestion in the network. A possible solution to these problems is the concept of active generator. The active generator will be very flexible and able to manage the power delivery as in a conventional generator system. This active generator includes the PV array with combination of energy storage technologies with proper power conditioning devices. The PV array output is weather dependent, and therefore the PV power output predictability is important for operational planning of the off-grid system. Many manufacturers of PV system power condition devices are designing and developing new type of inverters, which can work for delivering the power from PV system in coordination with energy storage batteries as conventional power plant.

Proper sizing of a photovoltaic (PV) system is essential to reduce lifecycle costs. This research presents a LabVIEW-based tool developed to optimize the DC nominal capacity of a self-consumption PV system without storage, connected to the electrical grid. The tool minimizes the system’s net present cost (NPC) using two main inputs: an annual hourly load profile and solar irradiance data. It plots NPC as a function of DC capacity and selects the capacity corresponding to the curve’s minimum value. To demonstrate its functionality, the tool was applied using data from San Pedro Sula, Honduras. Three scenarios were evaluated: (1) surplus PV energy injected into the grid was discarded; (2) a net billing scheme was implemented; and (3) a net metering scheme was considered. The latter two aimed to improve economic performance by compensating excess generation. Results show that reducing the NPC leads to an increase in the optimal DC capacity. Therefore, the tool effectively optimizes system sizing based on financial criteria. Additionally, self-consumption and self-sufficiency indexes were calculated for each scenario. The self-consumption index decreases as PV capacity increases, since more energy is generated than used. In contrast, the self-sufficiency index increases with PV capacity, up to a point where additional generation no longer matches consumption without energy storage. The proposed tool provides an accessible and effective approach for the techno-economic design of residential PV systems in regions lacking clear regulatory frameworks for managing surplus energy.

The increase in electricity prices in Pakistan has placed a heavy burden on consumers. The installation of rooftop solar Photovoltaic (PV) systems with net metering has emerged as a practical and sustainable solution to alleviate this issue. This study examines the benefits of net metering emphasizing its potential to reduce electricity bills and mitigate global warming by curtailing carbon emissions. Data pertaining to residential electricity usage and net-metering consumers in Karachi from 2018 to 2022 was examined to assess variations in electricity costs and determine potential savings through net metering. The analysis reveals a notable 375% rise in the average monthly expenditure on electricity for residential consumers in Karachi since 2018. Following the introduction of net metering in 2018, the number of consumers increased by 6,250% in 2022 compared to 2018. Solar net-metering consumers enjoyed an average monthly savings of 32% on electricity bills and an annual monetary benefit of approximately 275%. Furthermore, solar net metering has contributed approximately 11.64 MW of electricity to Karachi's grid, resulting in a reduction of 686,348 Kg/TJ in carbon emissions. It is recommended that government invest in providing subsidies for solar system to promote the adoption of solar electricity in Pakistan.