Results for “off-grid” — Page 2

DOE OSTI2025

CalTestBed - Delphire - Testing and Evaluation of Delphire Sentinel System (CRADA Final Report)

The Delphire Sentinel is a modular fire detection and communications system operating as a mobile field unit, with low voltage DC power supplied by onboard photovoltaics (PV) and batteries. The Sentinel addresses several aspects of fire detection, communications and data analysis. The Sentinel's mobility enables it to be rapidly deployed and operate independently of existing power and communications networks. The duration of independent operation depends critically on the energy consumption of the systems and performance of the onboard PV and battery. The purpose of this testing is to ascertain the power draw and energy consumption of the Delphire Sentinel prototype system under several operational states, including various data transfer packet sizes, transmission time and frequencies, and communication pathways (Wi-Fi, cellular, satellite) expected to be encountered in field deployments. It will also include procedures to test the ability of the Sentinel to operate for extended periods without loss of functionality. Based on results from energy and power measurements, and anticipated duty cycles in field deployments, we will model annual system autonomy (e.g. loss of load probability) for off-grid operation in representative locations.

47 OTHER INSTRUMENTATION↗

DOE OSTI2026

Phenomena Identification and Ranking Tables for High Temperature Gas-Cooled Microreactors

Micro-scaled high-temperature gas-cooled reactors (micro-HTGRs) offer a promising option for reliable power in remote or off-grid locations. While the safety characteristics of modular HTGRs have been widely studied, a micro-HTGR configuration alters several key thermal-fluid phenomena that govern both normal operation and passive decay-heat removal. In many proposed concepts, the reactor vessel is oriented horizontally and integrated into an ISO shipping container to enhance transportability and modular deployment. This report documents a Phenomena Identification and Ranking Table (PIRT) exercise focused on the thermal hydraulic safety phenomena relevant to all micro-HTGRs. The objective is to systematically identify, describe, and rank the importance, uncertainty, and modeling complexity of the key phenomena that control core and vessel temperatures during normal operation, pressurized conduction cooldown (PCC), and depressurized conduction cooldown (with air ingress) conditions.

22 - GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2026

Halau Uma: Kahikinui Community Cultural, Educational, and Resilience Center Preliminary Design Technical Assistance Summary Report

The Kahikinui Homestead Community in Maui faces energy resilience challenges due to its remote, off-grid location. This report summarizes preliminary technical assistance to design a microgrid for six modular homes using solar PV, wind, and battery storage. Results indicate that a hybrid PV and battery system, supplemented by small wind turbines, offers a cost-effective, resilient solution supporting energy independence and disaster preparedness.

Quiroz, Jimmy Edward [Sandia National Laboratories↗

DOE OSTI2026

Kauhale 'O Kipapa: Kahikinui Community Cultural, Educational, and Resilience Center Preliminary Design Technical Assistance Summary Report

The Kahikinui Homestead Community in Maui faces energy resilience challenges due to its remote, off-grid location. This report summarizes preliminary technical assistance to design a microgrid for six modular homes using solar PV, wind, and battery storage. Findings show hybrid PV and battery systems, supplemented by small wind turbines, offer cost-effective, resilient solutions. This work supports enhanced energy independence and disaster preparedness for the community.

Quiroz, Jimmy Edward [Sandia National Laboratories↗

DOE OSTI2025

Evaluating the potential of short-term instrument deployment to improve distributed wind resource assessment

Distributed wind projects, which are connected at the distribution level of an electricity system or in off-grid applications to serve specific or local energy needs, often rely solely on wind resource models to establish wind speed and energy generation expectations. Historically, anemometer loan programs have provided an affordable avenue for more accurate onsite wind resource assessment, and the lowering cost of lidar systems has shown similar advantages for more recent assessments. While a full 12 months of onsite wind measurement is the standard for correcting model-based long-term wind speed estimates for utility-scale wind farms, the time and capital investment involved in gathering onsite measurements must be reconciled with the energy needs and funding opportunities that drive expedient deployment of distributed wind projects. Much literature exists to quantify the performance of correcting long-term wind speed estimates with 1 or more years of observational data, but few studies explore the impacts of correcting with months-long observational periods. This study aims to answer the question of how short you can go in terms of the observational time period needed to make impactful improvements to model-based long-term wind speed estimates. Three algorithms, multivariable linear regression, adaptive regression splines, and regression trees, are evaluated for their skill at correcting long-term wind resource estimates from the European Centre for Medium-Range Weather Forecasts Reanalysis version 5 (ERA5) using months-long periods of observational data from 66 locations across the US. On average, correction with even 1 month of observations provides significant improvement over the baseline ERA5 wind speed estimates and produces median bias magnitudes and relative errors within 0.22 m s −1 and 4 percentage points of the median bias magnitudes and relative errors achieved using the standard 12 months of data for correction. However, in cases when the shortest observational periods (1 to 2 months) used for correction are not well correlated with the overlapping ERA5 reference, the resultant long-term wind speed errors are worse than those produced using ERA5 without correction. Summer months, which are characterized by weaker relative wind speeds and standard deviations for most of the evaluation sites, tend to produce the worst results for long-term correction using months-long observations. The three tested algorithms perform similarly for long-term wind speed bias; however, regression trees perform notably worse than multivariable linear regression and adaptive regression splines in terms of correlation when using 6 months or less of observational data for correction. Translating the analysis to wind energy, median relative errors in the capacity factor are on average within 10 % using 1 month of training. If the observation period used for correction is not well correlated with the reference data, however, misrepresentation of the observed capacity factor can be substantial. The risk associated with poor correlation between the observed and reference datasets decreases with increasing training period length. In the worst-correlation scenarios, the median capacity factor relative errors from using 1, 3, and 6 months are within 47 %, 26 %, and 16 %, respectively.

17 WIND ENERGY↗

NASA NTRS1979

A solar thermal electric power plant for small communities

A solar power plant has been designed with a rating of 1000-kW electric and a 0.4 annual capacity factor. It was configured as a prototype for plants in the 1000 to 10,000-kWe size range for application to small communities or industrial users either grid-connected or isolated from a utility grid. A small central receiver was selected for solar energy collection after being compared with alternative distributed collectors. Further trade studies resulted in the selection of Hitec (heat transfer salt composed of 53 percent KNO3, 40 percent NaNO2, 7 percent NaNO3) as both the receiver coolant and the sensible heat thermal stroage medium and the steam Rankine cycle for power conversion. The plant is configured with road-transportable units to accommodate remote sites and minimize site assembly requirements. Results of the analyses indicate that busbar energy costs are competitive with diesel-electric plants in certain situations, e.g., off-grid, remote regions with high insolation. Sensitivity of energy costs to plant power rating and system capacity factor are given.

Holl, R. J.↗

NASA NTRS2002

Powering the Future

Stirling Technology Company (STC) developed the RG-350 convertor using components from separate Goddard Space Center and U.S. Army Natick SBIR contracts. Based on the RG-350, STC commercialized a product line of Stirling cycle generator sets, known as RemoteGen(TM), with power levels ranging from 10We to 3kWe. Under SBIR agreements with Glenn Research Center, the company refined and extended the capabilities of the RemoteGen convertors. They can provide power in remote locations by efficiently producing electricity from multiple-fuel sources, such as propane, alcohol, gasoline, diesel, coal, solar energy, or wood pellets. Utilizing any fuel source that can create heat, RemoteGen enables the choice of the most appropriate fuel source available. The engines operate without friction, wear, or maintenance. These abilities pave the way for self-powered appliances, such as refrigerators and furnaces. Numerous applications for RemoteGen include quiet, pollution-free generators for RVs and yachts, power for cell phone towers remote from the grid, and off-grid residential power variously using propane, ethanol, and solid biomass fuels. One utility and the National Renewable Energy Laboratory are evaluating a solar dish concentrator version with excellent potential for powering remote irrigation pumps.

Source record↗

NASA NTRS2005

Contour Error Map Algorithm

The contour error map (CEM) algorithm and the software that implements the algorithm are means of quantifying correlations between sets of time-varying data that are binarized and registered on spatial grids. The present version of the software is intended for use in evaluating numerical weather forecasts against observational sea-breeze data. In cases in which observational data come from off-grid stations, it is necessary to preprocess the observational data to transform them into gridded data. First, the wind direction is gridded and binarized so that D(i,j;n) is the input to CEM based on forecast data and d(i,j;n) is the input to CEM based on gridded observational data. Here, i and j are spatial indices representing 1.25-km intervals along the west-to-east and south-to-north directions, respectively; and n is a time index representing 5-minute intervals. A binary value of D or d = 0 corresponds to an offshore wind, whereas a value of D or d = 1 corresponds to an onshore wind. CEM includes two notable subalgorithms: One identifies and verifies sea-breeze boundaries; the other, which can be invoked optionally, performs an image-erosion function for the purpose of attempting to eliminate river-breeze contributions in the wind fields.

Merceret, Francis↗

NASA NTRS2011

Jitter Controller Software

Sinusoidal jitter is produced by simply modulating a clock frequency sinusoidally with a given frequency and amplitude. But this can be expressed as phase jitter, frequency jitter, or cycle-to-cycle jitter, rms or peak, absolute units, or normalized to the base clock frequency. Jitter using other waveforms requires calculating and downloading these waveforms to an arbitrary waveform generator, and helping the user manage relationships among phase jitter crest factor, frequency jitter crest factor, and cycle-to-cycle jitter (CCJ) crest factor. Software was developed for managing these relationships, automatically configuring the generator, and saving test results documentation. Tighter management of clock jitter and jitter sensitivity is required by new codes that further extend the already high performance of space communication links, completely correcting symbol error rates higher than 10 percent, and therefore typically requiring demodulation and symbol synchronization hardware to operating at signal-to-noise ratios of less than one. To accomplish this, greater demands are also made on transmitter performance, and measurement techniques are needed to confirm performance. It was discovered early that sinusoidal jitter can be stepped on a grid such that one can connect points by constant phase jitter, constant frequency jitter, or constant cycle-cycle jitter. The tool automates adherence to a grid while also allowing adjustments off-grid. Also, the jitter can be set by the user on any dimension and the others are calculated. The calculations are all recorded, allowing the data to be rapidly plotted or re-plotted against different interpretations just by changing pointers to columns. A key advantage is taking data on a carefully controlled grid, which allowed a single data set to be post-analyzed many different ways. Another innovation was building a software tool to provide very tight coupling between the generator and the recorded data product, and the operator's worksheet. Together, these allowed the operator to sweep the jitter stimulus quickly along any of three dimensions and focus on the response of the system under test (response was jitter transfer ratio, or performance degradation to the symbol or codeword error rate). Additionally, managing multi-tone and noise waveforms automated a tedious manual process, and provided almost instantaneous decision- making control over test flow. The code was written in LabVIEW, and calls Agilent instrument drivers to write to the generator hardware.

Lansdowne, Chatwin↗

NASA NTRSDate not supplied

Changes in Characteristics of Future Climate Across the U.S.: Time Series Analysis of Climate Model Data by NASA POWER

NASA’s Prediction of Worldwide Energy Resource (POWER) project facilitates the use of NASA Earth Science data holdings within the energy, agricultural, and building heating/cooling design industries. POWER packages solar and meteorological data at various temporal levels from several NASA projects in a user friendly GIS-enabled web services system (https://power.larc.nasa.gov). Data users can access these data either through an intuitive data viewer, image services fully integrable with GIS analysis, connections in the cloud through an Amazon Web Services S3 Bucket, or fully customizable access through an API. Data provided by POWER has been used to remotely monitor solar array fields and integrated in a sizing tool for off-grid solar and storage systems. POWER data has also been coupled with key building decision tools to support design and retrofitting of building energy systems for energy efficiency and reduction of greenhouse gases. POWER is now developing capabilities to provide time series of the projected future evolution of surface quantities important to future energy production and use, such as heating/cooling degree days, temperature, wind speed, and downwelling solar flux. We present here a range of possible future changes in these quantities at locations throughout the continental United States. We show how both average and extreme values of the quantities will evolve from present-day to future climate conditions. We plan to provide these projections for users in the energy and sustainable energy communities.

Bradley M. Hegyi↗

NASA NTRSDate not supplied

NASA POWER: Providing Present and Future Climate Services Based on NASA Data for the Energy, Agricultural, and Sustainable Buildings Communities

NASA’s Prediction of Worldwide Energy Resource (POWER) project facilitates the use of NASA Earth Science data holdings within the renewable energy, agricultural, and building heating/cooling design industries. POWER packages solar and meteorological data at various temporal levels from several NASA projects in a user friendly GIS-enabled web services system (https://power.larc.nasa.gov). Data users can access these data either through an intuitive data viewer, image services fully integrable with GIS analysis, connections in the cloud through an Amazon Web Services S3 Bucket, or fully customizable access through an API. Data provided by POWER has been successfully used by decision makers to support actions that address climate change. For example, POWER data has been used to remotely monitor solar array fields and integrated in a sizing tool for off-grid solar and storage systems. POWER data has also been coupled with key building decision tools to support design and retrofitting of building energy systems for energy efficiency and reduction of greenhouse gases. POWER is now developing climate services to provide time series of the projected future evolution of key quantities that interest our users, such as heating/cooling degree days, temperature, wind speed, and downwelling solar flux. We demonstrate the potential of the new climate services by presenting here a range of possible future changes in these quantities at different NASA centers across the continental United States. These data services are based on downscaled climate model data from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) data set. We highlight the important insights that new climate services can provide. Our climate services will help our user communities quantify the impacts of climate change to support their key decisions in planning for the future, both inside and outside the Federal Government, especially for decisions in renewable energy and in building heating and cooling.

Bradley Hegyi↗

DOE OSTI2025

General field evaluation in high-order meshes on GPUs

Robust and scalable function evaluation at any arbitrary point in the finite/spectral element mesh is required for querying the partial differential equation solution at points of interest, comparison of solution between different meshes, and Lagrangian particle tracking. This is a challenging problem, particularly for high-order unstructured meshes partitioned in parallel with MPI, as it requires identifying the element that overlaps a given point and computing the corresponding reference space coordinates. Here, we present a robust and efficient technique for general field evaluation in large-scale high-order meshes with quadrilaterals and hexahedra. In the proposed method, a combination of globally partitioned and processor-local maps are used to first determine a list of candidate MPI ranks, and then locally candidate elements that could contain a given point. Next, element-wise bounding boxes further reduce the list of candidate elements. Finally, Newton’s method with trust region is used to determine the overlapping element and corresponding reference space coordinates. Since GPU-based architectures have become popular for accelerating computational analyses using meshes with tensor-product elements, specialized kernels have been developed to utilize the proposed methodology on GPUs. The method is also extended to enable general field evaluation on surface meshes. The paper concludes by demonstrating the use of the proposed method in various applications ranging from mesh-to-mesh transfer during r-adaptivity to Lagrangian particle tracking.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2024

Guide de base pour l'energie solaire hors reseau en Haiti: 7. Elements des modeles commerciaux pour le solaire hors reseau

Cette formation donne un apercu des informations et des concepts cles de l'energie solaire hors reseau en Haiti, renforcant ainsi les connaissances fondamentales et la capacite de catalyser l'interet pour l'energie solaire hors reseau pour l'electrification rurale en Haiti. Ce cours a rythme libre est offert en anglais et en francais et couvre une variete de sujets lies a l'acces a l'energie en Haiti, notamment les produits solaires hors reseau, le potentiel du marche en Haiti, les considerations liees a l'offre et a la demande, la conception, l'installation et la maintenance du systeme, -modeles commerciaux solaires en reseau, modelisation financiere, genre et acces a l'energie, utilisation productive de l'energie et adaptation au climat. La formation est destinee aux etudiants universitaires, aux partenaires gouvernementaux, aux ONG, aux bailleurs de fonds, aux partenaires de developpement, aux professionnels, etc. Aucune connaissance prealable du solaire hors reseau ou d'Haiti n'est requise pour beneficier de cette formation. See NREL/PR-7A40-89250 for the English translation of this document.

business↗

DOE OSTI2024

Guide de base pour l'energie solaire hors reseau en Haiti: 8. Modelisation financiere pour le solaire hors reseau

Cette formation donne un apercu des informations et des concepts cles de l'energie solaire hors reseau en Haiti, renforcant ainsi les connaissances fondamentales et la capacite de catalyser l'interet pour l'energie solaire hors reseau pour l'electrification rurale en Haiti. Ce cours a rythme libre est offert en anglais et en francais et couvre une variete de sujets lies a l'acces a l'energie en Haiti, notamment les produits solaires hors reseau, le potentiel du marche en Haiti, les considerations liees a l'offre et a la demande, la conception, l'installation et la maintenance du systeme, -modeles commerciaux solaires en reseau, modelisation financiere, genre et acces a l'energie, utilisation productive de l'energie et adaptation au climat. La formation est destinee aux etudiants universitaires, aux partenaires gouvernementaux, aux ONG, aux bailleurs de fonds, aux partenaires de developpement, aux professionnels, etc. Aucune connaissance prealable du solaire hors reseau ou d'Haiti n'est requise pour beneficier de cette formation. See NREL/PR-7A40-89251 for the English translation of this document.

ENERGY PLANNING, POLICY, AND ECONOMY,SOLAR ENERGY↗

DOE OSTI2024

Guide de base pour l'energie solaire hors reseau en Haiti: 6. Installation, exploitation et entretien des systemes solaires hors reseau

Cette formation donne un apercu des informations et des concepts cles de l'energie solaire hors reseau en Haiti, renforcant ainsi les connaissances fondamentales et la capacite de catalyser l'interet pour l'energie solaire hors reseau pour l'electrification rurale en Haiti. Ce cours a rythme libre est offert en anglais et en francais et couvre une variete de sujets lies a l'acces a l'energie en Haiti, notamment les produits solaires hors reseau, le potentiel du marche en Haiti, les considerations liees a l'offre et a la demande, la conception, l'installation et la maintenance du systeme, -modeles commerciaux solaires en reseau, modelisation financiere, genre et acces a l'energie, utilisation productive de l'energie et adaptation au climat. La formation est destinee aux etudiants universitaires, aux partenaires gouvernementaux, aux ONG, aux bailleurs de fonds, aux partenaires de developpement, aux professionnels, etc. Aucune connaissance prealable du solaire hors reseau ou d'Haiti n'est requise pour beneficier de cette formation. See NREL/PR-7A40-89249 for the English translation of this document.

ENERGY PLANNING, POLICY, AND ECONOMY,SOLAR ENERGY↗

DOE OSTI2024

Guide de base pour l'energie solaire hors reseau en Haiti: 9. Genre et acces a l'energie

Cette formation donne un apercu des informations et des concepts cles de l'energie solaire hors reseau en Haiti, renforcant ainsi les connaissances fondamentales et la capacite de catalyser l'interet pour l'energie solaire hors reseau pour l'electrification rurale en Haiti. Ce cours a rythme libre est offert en anglais et en francais et couvre une variete de sujets lies a l'acces a l'energie en Haiti, notamment les produits solaires hors reseau, le potentiel du marche en Haiti, les considerations liees a l'offre et a la demande, la conception, l'installation et la maintenance du systeme, -modeles commerciaux solaires en reseau, modelisation financiere, genre et acces a l'energie, utilisation productive de l'energie et adaptation au climat. La formation est destinee aux etudiants universitaires, aux partenaires gouvernementaux, aux ONG, aux bailleurs de fonds, aux partenaires de developpement, aux professionnels, etc. Aucune connaissance prealable du solaire hors reseau ou d'Haiti n'est requise pour beneficier de cette formation. See NREL/PR-7A40-89252 for the English translation of this document.

ENERGY PLANNING, POLICY, AND ECONOMY,SOLAR ENERGY↗

DOE OSTI2024

Guide de base pour l'energie solaire hors reseau en Haiti: 11. Adaptation et resilience au climat

Cette formation donne un apercu des informations et des concepts cles de l'energie solaire hors reseau en Haiti, renforcant ainsi les connaissances fondamentales et la capacite de catalyser l'interet pour l'energie solaire hors reseau pour l'electrification rurale en Haiti. Ce cours a rythme libre est offert en anglais et en francais et couvre une variete de sujets lies a l'acces a l'energie en Haiti, notamment les produits solaires hors reseau, le potentiel du marche en Haiti, les considerations liees a l'offre et a la demande, la conception, l'installation et la maintenance du systeme, -modeles commerciaux solaires en reseau, modelisation financiere, genre et acces a l'energie, utilisation productive de l'energie et adaptation au climat. La formation est destinee aux etudiants universitaires, aux partenaires gouvernementaux, aux ONG, aux bailleurs de fonds, aux partenaires de developpement, aux professionnels, etc. Aucune connaissance prealable du solaire hors reseau ou d'Haiti n'est requise pour beneficier de cette formation. See NREL/PR-7A40-89254 for the English translation of this document.

adaptation↗

DOE OSTI2024

Guide de base pour l'energie solaire hors reseau en Haiti: 4. Considerations relatives a la demande et a l'offre pour l'energie solaire hors reseau

Cette formation donne un apercu des informations et des concepts cles de l'energie solaire hors reseau en Haiti, renforcant ainsi les connaissances fondamentales et la capacite de catalyser l'interet pour l'energie solaire hors reseau pour l'electrification rurale en Haiti. Ce cours a rythme libre est offert en anglais et en francais et couvre une variete de sujets lies a l'acces a l'energie en Haiti, notamment les produits solaires hors reseau, le potentiel du marche en Haiti, les considerations liees a l'offre et a la demande, la conception, l'installation et la maintenance du systeme, -modeles commerciaux solaires en reseau, modelisation financiere, genre et acces a l'energie, utilisation productive de l'energie et adaptation au climat. La formation est destinee aux etudiants universitaires, aux partenaires gouvernementaux, aux ONG, aux bailleurs de fonds, aux partenaires de developpement, aux professionnels, etc. Aucune connaissance prealable du solaire hors reseau ou d'Haiti n'est requise pour beneficier de cette formation. See NREL/PR-7A40-89247 for the English translation of this document.

customers↗