Engineering Papers⌕ Search

SEARCH · Engineering Papers

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Optical Durability of Contemporary PV Encapsulants Through Artificial UV Weathering

Modern c-Si photovoltaic (PV) cells provide high performance but can be vulnerable to ultraviolet light induced degradation (UV-ID). Encapsulants, if chosen correctly, can mitigate UV-ID of the PV cell. Here, we explore performance and durability of 14 commercial encapsulant materials before, during, and after irradiation with UV-containing light. Materials include contemporary, polymer-based encapsulants with a base polymer of poly (ethylene co-vinyl acetate) (EVA), polyethylene-..alpha..-olefin (POE), or their composite (EPE). Polymers contain additives that induce UV-blocking, UV-transmitting, or UV-downshifting properties. We use test coupons to study degradation in a chamber held at 65 degrees C under a xenon light source for up to 4000 h of exposure, corresponding to a cumulative dose of 11.5 MJ/m2 at 340 nm. We examine optical properties including spectral transmittance, yellowness index and spectral fluorescence, considering changes to both the encapsulant and glass as a function of weathering time. Degradation modes identified include discoloration, changes to UV cutoff wavelength, changes to solar-weighted transmittance, and most notably a change to the UV-managing properties of some additives. We propose the use of solar-weighted transmittance in the 300- to 400-nm range to better track performance changes in the UV region associated with the UV-related additive. This is especially relevant for the emerging class of UV-downshifting additives, as metrics like UV-cutoff can understate the degree of degradation or change in these materials. While most encapsulants show very little change after weathering, some show significant changes that directly impact how much UV light would reach an underlying cell.

14 SOLAR ENERGY↗
DOE OSTI2025

Novel Approach to PV Inverter Modeling and Simulation Leveraging Experiments, Learning Based Modeling and Co-Simulation

Photovoltaic (PV) inverter manufacturers use custom, proprietary control approaches and topologies in their inverter design. The proprietary nature of these approaches makes it challenging to share electromagnetic transients (EMT) domain models for system studies. This research work presents an approach to develop EMT models from experimental data. We use novel approach in experimental design, high fidelity data collection, use of learning-based modeling, and co-simulation to reduce the time taken to develop an EMT model for an inverter under test (IUT). We used a 20 kW off-the-shelf grid following PV inverter and subjected the inverter to controlled tests. The tests include voltage and frequency step changes, as well as solar irradiance variations. The recorded high frequency data were used to train a neural network model representing the dynamic behavior of the IUT. The model was subsequently imported into an EMT tool using co-simulation techniques, and thus completing the modeling effort.

black box inverter modeling↗
DOE OSTI2024

Benchmark High-Fidelity EMT Models for Power Grid with PV Plants

In recent times electromagnetic transient (EMT) modeling tools have been identified as one of the most important requirements in replicating, analyzing, and investigating the dynamics of the power grid with photovoltaic (PV) plants. However, there are no benchmark models for power grid with PVs to investigate emerging challenges with higher penetration of PVs (like trips and momentary cessations during faults from a region far away). To this end, in this paper, synthetic benchmark high-fidelity EMT dynamic models of power grid with large-scale PV plants are presented. The models are developed in PSCAD and PSCAD/Fortran. Simulation results for different use cases (events) and scenarios are presented.

Marthi, Phani Ratna Vanamali↗
DOE OSTI2024

Reinforcement Learning-Based Approach for EMT Automation of Large-Scale PV Plants

In the pursuit of efficient and precise modeling of large-scale power systems, particularly utility-scale photovoltaic (PV) plants, Electromagnetic Transient (EMT) simulations play a crucial role. As utility-scale PV plants increase in size and complexity, traditional computational methods become inadequate, necessitating more advanced techniques. This paper highlights the progressive efforts made to accelerate EMT simulations. A novel continuous reinforcement learning (RL) strategy is explored to automate the differentiation and categorization of stiff and non-stiff differential algebraic equations (DAEs). The use of stiff and non-stiff integration methods applied to relevant parts of the DAEs assists with the speed-up of the simulations. The paper details the data acquisition, development and offline training of the RL model, leading to its validation that demonstrates a high precision in optimizing simulation methods. The proposed RL promises to significantly enhance the efficacy of EMT simulations, offering a robust framework for the future of power system analysis.

Xia, Qianxue↗
DOE OSTI2024

Artificial Replication of Field Soiling Losses on PV Modules

In this paper, we experimentally demonstrate an improved replication of field soiling losses using an indoor artificial soiling chamber and tests on anti-soiling coated PV modules and coupons. The primary focus is to use site-specific soil collected from module surface and replicate the natural soiling processes including dust concentration in the air, slow and gradual dust accumulation and sedimentation on the module surface during the dominant soiling season of the site of interest. The experiments were conducted on two sample sets having different anti-soiling properties. The first set contains commercial modules with two different surface properties retrieved after three years of exposure from a single PV plant in a mid-Atlantic location; the other set contain glass coupons with three different coating materials that were installed and exposed over 4 months, at Lemoore, California. Major field-representative factors considered here for the close replication in the chamber include: the use of dust collected from modules surfaces at the outdoor sites to give the same dust chemistry; dust particle size distribution and concentration; the charge size of dust (< 0.15 g per injection); field humidity, and module temperature. The effectiveness of antisoiling coatings (or surface properties) for both sample sets were ranked in the artificial testing and were found to be closely matching with the field rank orders of the respective sites and sample sets. This paper provides the rank ordering results to objectively demonstrate the replication of field soiling losses in the artificial soiling chamber.

artificial soiling↗
DOE OSTI2024

User Stories for PV Operations and Maintenance: Findings from the 2024 PVPMC Workshop

At the 2024 Photovoltaic (PV) Performance Modeling Workshop we collected user stories related to PV system monitoring, analytics, and operations and maintenance (O&M). In this context, user stories describe challenges with current practices and tools or imagining opportunities for improvements. From these user stories, we identified several near-term opportunities to improve photovoltaic system monitoring, analytics and O&M.

14 SOLAR ENERGY↗
DOE OSTI2025

PACT Perovskite PV Module Outdoor Test Protocol (Version 0.2)

The purpose of this protocol is to define procedures and practices to be used by the PACT center for field testing of metal halide perovskite (MHP) photovoltaic (PV) modules. The protocol defines the physical, electrical, and analytical configuration of the tests and applies equally to mounting systems at a fixed orientation or sun tracking systems. While standards exist for outdoor testing of conventional PV modules, these do not anticipate the unique electrical behavior of perovskite cells. Further, the existing standards are oriented toward mature, relatively stable products with lifetimes that can be measured on the scale of years to decades. The state of the art for MHP modules is still immature with considerable sample to sample variation among nominally identical modules. Version 0.0 of this protocol does not define a minimum test duration, although the intent is for modules to be fielded for periods ranging for weeks to months. This protocol draws from relevant parts of existing standards, and where necessary includes modifications specific to the behavior of perovskites.

14 SOLAR ENERGY↗
DOE OSTI2025

Cost Benefit Analysis of Solar PV for the City of Oldsmar, FL

The City of Oldsmar is in the early stages of exploring renewable energy opportunities as a part of their initiative to reduce energy costs, improve backup power capacity, and begin the transition to more sustainable operations. The city is particularly interested in deploying a floating or ground-mounted solar PV system at its wastewater treatment plant. Currently, there are no solar PV installations in Oldsmar and there has been hesitancy to implement such a project due to the possible capital costs and limited technical capacity. Despite this the initiative has gained internal buy-in among staff working for the city. To assist with gaining more buy-in and making future decisions the city sought technical assistance (TA) from the Energy to Communities (E2C) Expert Match Program. Through the Expert Match Program, the city received TA provided by the Pacific Northwest National Lab (PNNL) to evaluate the cost effectiveness of several solar options. This report details the analysis and results of the work performed for TA.

14 SOLAR ENERGY↗
DOE OSTI2025

Community Center and Administration Solar PV Project

The Tribe installed two (2) roof mounted solar PV systems with a total production of approximately 146 kW on the Paskenta Band of Nomlaki Indians’ Community Center in Corning, CA. One of the two solar PV arrays provided 90% of the Community Center’s energy, while the second array provided nearly 100% of the adjacent administration building’s energy.

14 SOLAR ENERGY↗
DOE OSTI2025

Preliminary Assessment of PV + Electric Storage Options at the Energy Coordinating Agency

NREL used the REopt (R) platform to evaluate the techno-economic potential of adding solar PV and electric storage at the Energy Coordinating Agency (ECA) in Philadelphia, PA. The site has access to 600 PV panels (rated at 305 W each) and would like to evaluate the potential of pairing them with battery storage to offset electricity costs, increase renewable energy usage, and establish an onsite microgrid.

14 SOLAR ENERGY↗
DOE OSTI2026

Addressing the split incentive challenge for rooftop solar PV and battery energy storage in multifamily rental buildings (CRADA 638 Final Report)

This project advances the understanding of how roof solar PV systems and battery energy storage systems (BESS) can be effectively deployed in multifamily residential buildings, a sector that has historically faced barriers due to misaligned incentives between landlords and tenants. By leveraging high-resolution building stock data and simulation tools, the research demonstrates how energy consumption patterns vary across building types, climates, and occupant characteristics, and how these variations influence the optimal sizing and operation of distributed energy resources. A key contribution is the development of a publicly accessible, web-based tool named RESIDE (Residential Energy Systems & Infrastructure Data Evaluation) that allows users to explore building energy use and evaluate solar and battery configurations without requiring specialized expertise. This significantly lowers the barrier to entry for stakeholders such as property owners, utilities, and policymakers. From a technical perspective, the project shows that integrating rooftop solar PV with battery energy storage can substantially reduce electricity costs and peak demand through strategies such as energy arbitrage and peak shaving. The modeling framework incorporates real-world constraints, including time-of-use electricity pricing and battery degradation, providing realistic and actionable insights. Economically, the results indicate that properly sized systems can deliver meaningful cost savings, improving the feasibility of energy investments in multifamily housing. More broadly, the project benefits the public by supporting the transition to affordable and reliable energy, particularly in rental multifamily housing where adoption has traditionally lagged.

14 SOLAR ENERGY↗
NASA NTRS1989

Further evidence for a circumstellar disk around PV Cephei

Spectra of PV Cephei from 2 to 4 microns reveal a moderately strong 3 micron ice-absorption feature. Normally seen in objects with high visual obscuration, A(V) greater than 10, this absorption in an object with A(V) = 3.5-5.0 suggests the existence of a dense circumstellar disk. This paper discusses the evidence for a disk from this data and other wavelength regions, the possible origin of the 3-micron feature in PV Cephei, and the relationship between this object and other young stellar objects.

Van Citters, G. W., Jr.↗
NASA NTRS1989

Launch packaging options for the PV power module cargo element

NASA recently embarked on the Space Station Freedom program, which will utilize the Shuttle Orbiter for transportation to orbit. Each flight is unique in terms of the hardware that is manifested and the method by which it is integrated to form viable cargo elements. Various constraints determine the packaging options for the three PV power module combined assemblies. Several packaging options for the PV power module cargo element are presented. These options are discussed in terms of their impact on the overall flight hardware manifest as determined by the various constraints.

Hoberecht, Mark A.↗
NASA NTRS2005

Report of the Workshop on Next-Generation Space PV: Thin Films

A workshop on the future use of thin-film photovoltaic devices in space power was convened at the 16th Space Photovoltaic Research and Technology Conference held at the NASA Glenn Research Center in Cleveland, OH. This workshop began by addressing: 1) What are the leading impediments or technological challenges to be overcome with regard to the use of thin-film PV in space? 2) What is the status of organic based cells? Will they have a role in space PV, if so when? and 3) What about an integrated PV/Li battery array-up and down sides? A discussion on these three questions pertaining to future use of thin film devices for space power systems is presented

Raffaelle, R. P.↗
NASA NTRS2009

Managing PV Power on Mars - MER Rovers

The MER Rovers have recently completed over 5 years of operation! This is a remarkable demonstration of the capabilities of PV power on the Martian surface. The extended mission required the development of an efficient process to predict the power available to the rovers on a day-to-day basis. The performance of the MER solar arrays is quite unlike that of any other Space array and perhaps more akin to Terrestrial PV operation, although even severe by that comparison. The impact of unpredictable factors, such as atmospheric conditions and dust accumulation (and removal) on the panels limits the accurate prediction of array power to short time spans. Based on the above, it is clear that long term power predictions are not sufficiently accurate to allow for detailed long term planning. Instead, the power assessment is essentially a daily activity, effectively resetting the boundary points for the overall predictive power model. A typical analysis begins with the importing of the telemetry from each rover's previous day's power subsystem activities. This includes the array power generated, battery state-of-charge, rover power loads, and rover orientation, all as functions of time. The predicted performance for that day is compared to the actual performance to identify the extent of any differences. The model is then corrected for these changes. Details of JPL's MER power analysis procedure are presented, including the description of steps needed to provide the final prediction for the mission planners. A dust cleaning event of the solar array is also highlighted to illustrate the impact of Martian weather on solar array performance

Mars dust↗