A Two-Layer Approach for Estimating Behind-the-Meter PV Generation Using Smart Meter Data
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Engineering↗
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Results for “PV”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Coordinated Use of Smart Inverters with Legacy Voltage Regulating Devices in Distribution Systems with High Distributed PV Penetration — Increase CVR Energy Savings
This paper studies the coordinated use of smart inverters with legacy voltage regulating devices to help increase the energy savings from conservation voltage reduction (CVR) in distribution systems with high photovoltaic penetration. Two voltage optimization algorithms are developed to evaluate the CVR benefit by considering two types of smart inverter functions: aggregated reactive power control and autonomous volt/VAR control. In each algorithm, smart inverters are coordinately controlled with the operation of legacy voltage regulating devices including load tap changers and capacitor banks. Both algorithms are tested on representative utility distribution system models. In conclusion, simulation results demonstrate that the proposed algorithms can achieve around 1.8-3.6% energy savings when only using legacy voltage regulating devices and an additional 0.3-0.9% when adding smart inverters.
14 SOLAR ENERGY↗
A Hybrid Simulation Tool for the Study of PV Integration Impacts on Distribution Networks
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Energy & Fuels↗
Deep Reinforcement Scheduling of Energy Storage Systems for Real-time Voltage Regulation in Unbalanced LV Networks with High PV Penetration
The ever-growing higher penetration of distributed energy resources (DERs) in low-voltage (LV) distribution systems brings both opportunities and challenges to voltage support and regulation. This paper proposes a deep reinforcement learning (DRL)-based scheduling scheme of energy storage systems (ESSs) to mitigate system voltage deviations in unbalanced LV distribution networks. The ESS-based voltage regulation problem is formulated as a multi-stage quadratic stochastic program, with the objective of minimizing the expected total daily voltage regulation cost while satisfying operational constraints. While existing voltage regulation methods are mostly focused on onetime- step control, this paper explores a day-horizon systemwide voltage regulation problem. In other words, the size of action and state spaces are extremely high-dimensional and need to be delicately handled. Furthermore, in order to overcome the difficulty of modeling uncertainties and develop a realtime solution, a learn-to-schedule feedback control framework is proposed by adapting the problem to a model-free DRL setting. The proposed algorithm is tested on a customized 6-bus system and a modified IEEE 34-bus system. Simulation results validate the effectiveness and near-optimality of voltage regulation by ESS in comparison with a deterministic quadratic program solution.
Wang, Shengyi↗
An agent based model for joint placement of PV panels and green roofs
Photovoltaic panels generate electricity directly from sunlight, making them a favored renewable technology. Green roofs are rooftops covered with vegetation, which provide a variety of benefits, namely, reducing stormwater runoff, improving air quality, and biodiversity. Green roofs are capable of improving the efficiency of Photovoltaic panels, as shown by the recent studies. Optimal placement of Photovoltaic panels and green roofs is a challenging problem due to the complications imposed by uncertainties associated with future climate conditions, specifically due to climate change. An agent based model to optimally place Photovoltaic panels and green roofs is developed in this study. We propose a tabu search metaheuristic algorithm to solve the developed model. Then, a real-world case for a mid-sized city in the U.S. is solved as a case study for the model. We further conduct numerical analysis and provide insights.
Li, Xueping↗
PV Degradation Tools [SWR-20-71]
This open-source tool functions for calculating degradation of photovoltaic modules. For example, functions to calculate front and rear relative Humidity, as well as Acceleration Factors. A degradation calculation function is also being developed, considering humidity and spectral irradiances models.
Holsapple, Derek↗
Subtropical Jet in Reanalysis Data from STJ_PV
Subtropical jet position from a new method for locating the subtropical jet, called the tropopause gradient method. It is based on the peak gradient in potential temperature along the dynamic tropopause. This data has the identified subtropical jet latitude, level, and intensity across four different reanalysis products (CFSR-2, ERA-Interim, JRA-55, and MERRA-2), at both daily and monthly output frequency.
58 GEOSCIENCES↗
Optical and mechanical tolerances in hybrid concentrated thermal-PV solar trough
Not Available
14 SOLAR ENERGY↗
II-VI Material Integration With Silicon for Detector and PV Applications
Heteroepitaxial growth of high-quality II-VI-alloy materials on Si substrates is a well-established commercial growth process for infrared (IR) detector devices. However, it has only recently been recognized that these same processes may have important applications for production of high-efficiency photovoltaic devices. This submission reviews the process developments that have enabled effective heteroepitaxy of II-VI alloy materials on lattice-mismatched Si for IR detectors as a foundation to describe recent efforts to apply these insights to the fabrication of multijunction Si/CdZnTe devices with ultimate conversion efficiencies >40%. Reviewed photovoltaic studies include multijunction Si/CdZnTe devices with conversion efficiency of ~17%, analysis of structural and optoelectrical quality of undoped CdTe epilayer films on Si, and the effect that a Te-rich growth environment has on the structural and optoelectronic quality of both undoped and As-doped heteroepitaxial CdTe.
14 SOLAR ENERGY↗
Technical Comparative Analysis of "Best of Breed" Turnkey Si-Based Processes and Equipment, to be Used to Produce a Combined Multi-entity Research and Development Technology Roadmap for Thick and Thin Silicon PV
A side-by-side analysis was done on then currently available technology, along with roadmaps to push each particular option forward. Variations in turnkey line processes can and do result in finished solar device performance. Together with variations in starting material quality, the result is a distribution of efficiencies. Forensic analysis and characterization of each crystalline Si based technology will determine the most promising approach with respect to cost, efficiency and reliability. Forensic analysis will also shed light on the causes of binning variations. Si solar cells were forensically analyzed from each turn key supplier using a host of techniques
14 SOLAR ENERGY↗
Composites of Upgraded Metallurgical Grade (UMG) Si with Photovoltaic (PV) Grade Si
At the beginning of this project 125 wafers of UMG material blended with non-UMG were obtained in the various blends; 50/50,70/30,80/20. 90/10 and 100% UMG. Solar grade, non-UMG material was used for comparison. Many techniques for starting substrate evaluation were used including lifetime, resitivity, SEM, IPCMS. Some degree of gettering was implemented by lengthening the time of phosphorous diffusion. The UMG/solar blends resulted in 14.5% -15% efficiencies, and even 100% UMG showed 14.5% values, not less than standard cells manufactured at the time and an encouraging result for the prospects of using UMG material due to the lower $/watt. A later decline in the cost of Si and an emphasis on reaching higher efficiencies in general led to a vanishing interest in the use of UMG.
14 SOLAR ENERGY↗
Powering a Home with Just 25 Watts of Solar PV. Super-Efficient Appliances Can Enable Expanded Off-Grid Energy Service Using Small Solar Power Systems
Highly efficient direct current (DC) appliances have the potential to dramatically increase the affordability of off-grid solar power systems used for rural electrification in developing countries by reducing the size of the systems required. For example, the combined power requirement of a highly efficient color TV, four DC light emitting diode (LED) lamps, a mobile phone charger, and a radio is approximately 18 watts and can be supported by a small solar power system (at 27 watts peak, Wp). Price declines and efficiency advances in LED technology are already enabling rapidly increased use of small off-grid lighting systems in Africa and Asia. Similar progress is also possible for larger household-scale solar home systems that power appliances such as lights, TVs, fans, radios, and mobile phones. When super-efficient appliances are used, the total cost of solar home systems and their associated appliances can be reduced by as much as 50%. The results vary according to the appliances used with the system. These findings have critical relevance for efforts to provide modern energy services to the 1.2 billion people worldwide without access to the electrical grid and one billion more with unreliable access. However, policy and market support are needed to realize rapid adoption of super-efficient appliances.
14 SOLAR ENERGY↗
Final Technical Report: Integrated Distribution-Transmission Analysis for Very High Penetration Solar PV
Transmission and distribution simulations have historically been conducted separately, echoing their division in grid operations and planning while avoiding inherent computational challenges. Today, however, rapid growth in distributed energy resources (DERs)--including distributed generation from solar photovoltaics (DGPV)--requires understanding the unprecedented interactions between distribution and transmission. To capture these interactions, especially for high-penetration DGPV scenarios, this research project developed a first-of-its-kind, high performance computer (HPC) based, integrated transmission-distribution tool, the Integrated Grid Modeling System (IGMS). The tool was then used in initial explorations of system-wide operational interactions of high-penetration DGPV.
14 SOLAR ENERGY↗
DOE Los Alamos National Laboratory – PV Feasibility Assessment, 2015 Update, NREL Final Report
This report summarizes solar and wind potential for Los Alamos National Laboratory (LANL). This report is part of the “Los Alamos National Laboratory and Los Alamos County Renewable Generation” study.
14 SOLAR ENERGY↗
2015 South Carolina PV soft cost and workforce development Part I. Initial survey results
The South Carolina solar industry has surged over the past two years, largely due to the implementation of Act 236, and continues to grow at a rapid pace. At the beginning of 2014, there was little more than 3MW total spread across the state, but by the end of 2021, that state solar industry will have grown to over 300MW across all sectors. Prior to this study, there has been little publically available information on the solar industry in SC and throughout the Southeastern US. This makes SC a key case study of an emerging market, enabling the development of regional best practices in order to decrease associated costs and increase deployment.
14 SOLAR ENERGY↗
2016 Alabama PV soft cost and workforce development
The Southeastern US has the largest potential for growth in the solar industry. However, currently they languish behind the rest of the US. There are several bright spots including the large number of utility scale installations in North Carolina and the recent successes in South Carolina under Act 236. In order to better understand the impacts of state legislation on the growth of the solar industry in the SE US, the Savannah River National Laboratory has undertaken a study to look at the growth in each state in order to develop recommendations to help reduce the cost of solar and to spur the industry. This is the second report in the series. The first focused on developing cost metrics for South Carolina under Act 236. This report focuses on Alabama, the 49th ranked state for solar business, which has very similar population and median income to South Carolina. For this survey, the ten known in-state installers were contacted. Responses were received from seven, representing 70% of the installers, a majority of which provide both residential and commercial installations. Interestingly, none of the respondents serve the utility scale sector. Overall, costs for Alabama are on track with the rest of the country with a reported average cost of $3.29/W-DC for residential systems and $2.44/W-DC for commercial systems. 60% of this cost is attributed to hardware only. Of the remaining costs, installation contributed to the largest percentage of soft costs followed by overhead, marketing and sales, and permitting, respectively. This also closely mirrors results seen in South Carolina. Job growth in the industry is expected to proceed well. An expected 34-42 additional full time equivalent jobs were expected to be added in Alabama within the six month window following the survey period. During the three years following the survey, this number was expected to double with 89-97 additional jobs being added to the market. In both cases, a vast majority of these jobs were for installation professionals and electricians. Despite the cost of solar, the industry continues to struggle in Alabama, largely due to the absence of any statewide net metering legislation. By current best estimates, there are over 60 residential installations statewide; however, this number is difficult to track due to the lack of a State authority keeping a consolidated list of grid connected distributed power systems. In South Carolina, the Energy Office tracks and reports grid connected distributed power systems by all Cooperatives and utilities. In Alabama, the Energy Office does not fulfill this role and data must be collected directly from each utility and cooperative, which makes collection and analysis difficult. Having a central state agency track this information would be extremely useful towards developing state policy recommendations, particularly if net metering were enabled within the state.
29 ENERGY PLANNING, POLICY, AND ECONOMY↗