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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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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Data Analytics for Residential PV from Permit to Interconnect (Final Technical Report)

The main objective of this research is to provide novel insights into the effects of permitting, inspection, and interconnection (PII) processes on PV system installations—and in particular, into the relationship between PII processes and adoption timelines. This research can then be used to clarify the potential effect of various process changes on reducing PII timelines, customer cancellation rates, and related costs nationwide. NREL completed this research by assembling a data set of distributed, largely residential rooftop solar systems less than 50 kilowatts in size from participating solar installers. NREL produced five publications describing the effects that PII processes can have on adoption timelines nationwide, in addition to publishing an interactive data viewer with five years of PII cycle time data. This tool can be used by stakeholders to identify potential adoption timelines by local government.

14 SOLAR ENERGY↗
DOE OSTI2022

DSO+T: Expanded Study Results DSO+T Study: Volume 5

The Distribution System Operator with Transactive (DSO+T) study investigates the engineering and economic performance of a transactive energy retail market coordinating a high penetration of customer-side flexible energy assets. The study seeks to answer whether such an implementation is cost effective for customers, recovers sufficient revenue for DSOs, and is equally applicable and beneficial to a range of flexible asset types, renewable generation scenarios, and market assumptions. This report volume provides a detailed set of results for the DSO+T study extending results presented in Volumes 1, 2, and 4. The engineering and economic performance of the transactive energy scheme is presented for two separate flexible asset deployments: flexible loads (HVAC units and residential water heaters) and behind-the-meter batteries. The results of each transactive case are compared to a business-as-usual case. These cases are subject to two different renewable generation scenarios, a moderate renewable generation scenario, representative of current levels of renewable generation deployment, and a future high renewables scenario, including the increased deployment of rooftop solar photovoltaic and electric vehicles. The transactive coordination scheme is shown to produce effective and stable control and decrease peak loads 9–15%. The resulting annual demand flexibility provides net economic savings of $3.3–5.0B per year for a region the size of Texas. Detailed analysis shows that net benefits were seen for a range of distribution system operator, customer, and flexible asset types. Both participating customer (with transactive flexible assets) and nonparticipating customers (with nonflexible assets) see reductions in annual utility bills and net annual energy expenses in the range of 10–16%.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2024

Household Energy Burden in Lawrence, Massachusetts [Slides]

The City of Lawrence consists of 18 census tracts, of those, 9 census tracts have an average energy burden (the percent of income spent on energy bills) of 6% or greater. The Lawrence Stakeholders Coalition's (LSC) main goal is to "Reduce energy burden and create well-paying local jobs and businesses by increasing the distribution and use of sustainable technologies such as heat pumps, community and rooftop solar, and weatherization." As part of that goal, the LSC is interested in understanding Lawrence's pathway to electrification, specifically through the building sector. This technical assistance aims to assist the LSC's electrification and energy burden reduction planning by: 1) Identifying the most energy-burdened households by owner-occupied and renter-occupied housing status; 2) Identifying and quantifying the characteristics of the most energy-burdened housing units by housing type, age, and heating fuel type; 3) Identifying the tenure and housing types of the most energy-burdened and prevalent households for subsequent ResStock analysis of cost-effective efficiency upgrades.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2026

Progressing Analysis of Variable Electric Rates (PAVER) Study

The Progressing Analysis of Variable Electric Rates (PAVER) study analyzed the impact of a range of time-varying electric rates on the performance of a regional electric grid and the resulting costs for participating and non-participating customers. This analysis leveraged and extended the work of PNNL’s Distribution System Operator with Transactive (DSO+T) study. Five different rate designs were included: a flat volumetric energy charge, a typical Time of Use (TOU) rate, a dynamic energy (DE) rate (based on wholesale locational marginal prices), a dynamic energy and capacity (DE+C) rate, and, finally, a Block and Swing (B&S) rate that billed customers based on their average load profile at constant pricing, but used the DE+C dynamic price for load deviations from their average profile. These rates were analyzed in a large-scale co-simulation of an entire regional grid with a customer population representative of the current state. A large fraction (80%) of residential and commercial customers were assumed to participate in these time-varying rates with automatically controlled HVAC, water heaters, electric vehicles, and batteries. This study assumed no industrial sector participation. The DE and DE+C rates saw system peak loads reduced by 6-7%, while the large participation in the TOU rate case saw a significant rebound effect and a resulting peak load increase of >5%. The impacts to the annual and peak system demand impacted system wholesale prices and the overall grid operating costs. This cost structure determined the revenue needed to be collected from customers by each rate design. Participating customers on the DE and DE+C rates (located in one of the modeled DSOs) saw reductions in average annual electricity bills of 11-17% with average increases in monthly bill variation of no more than 13%. At such high participation levels, TOU customers saw 10% higher average annual bills (due to system-wide rebound effects) and average increased monthly bill variation of 16%. Residential owners of large flexible loads (such as electric vehicles) saw larger bill savings (17-20%) when on a fully dynamic rate. The presence of on-site generation (such as rooftop solar) did not appear to appreciably change customer outcomes. Customers on the Block and Swing rate did see 6% lower monthly bill variation (as intended) than the flat rate case, but at the expense of appreciable bill savings, which were only 3%, comparable to the savings seen by non-participants. Given this finding we recommend that additional research be conducted into how best various bill protection mechanisms can balance minimizing customer bill variation with providing financial incentives commensurate with the flexibility customers provide. We also recommend that customer outcomes be explored across a range of regions using current actual customer and system cost data.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

Muckleshoot Indian Tribe-Energy Deployment (MITED) Project

The Muckleshoot Indian Tribe (MIT) collaborated with our Project Partner, GRID Alternatives (GRID), to install 132 kilowatts of direct current (kW-DC) of rooftop solar on three Tribal facilities. The three facilities are the Tribe’s Youth Drop-In Center, Canoe Shed, and Water Treatment Facility. The solar PV systems were originally anticipated to offset approximately 45% of the aggregate annual electricity usage of the three buildings. A major aspect of the MIT-ED project was providing hands-on paid training to five Muckleshoot Building Maintenance workers in solar PV installations, operations, and maintenance. The scope of work aligns with the Tribe’s goals of building local capacity and providing real world work experience and potential career opportunities in solar PV to its citizens. The Building Maintenance Department committed five of its current FTE employees to the project. GRID provided guidance for the MIT project team on identifying paid trainees as well as end goals of skill development through training, including a long-term Operations and Maintenance (O&M) plan tailored to the Tribe’s goals of local capacity building and stewardship of natural resources.

14 SOLAR ENERGY↗
DOE OSTI2021

Distributed PV permitting survey responses

In 2019, NREL, in partnership with the Solar Energy Industries Association, developed a survey for PV installers on their experiences with delays and cancelations in the adoption process, including the impacts of permitting and interconnection. This dataset includes the anonymized responses from 147 representatives from 136 solar install companies.

14 SOLAR ENERGY↗
NASA NTRS1984

Edge Supports for Photovoltaic Modules

Mounting strips patterned after glazing gaskets. Easy to install supports for rooftop solar modules consist of extruded rubber mullions with locking zippers. Supports cut to length with utility knife and installed without special tools. Adaptable to many different roof configurations.

Maloney, T. J.↗
DOE OSTI2020

Grid Code Essentials and Streamlining Process for Interconnections

This presentation was part of a webinar entitled "A Practitioner's Guide to Implementing Solar Rooftop Programs and Navigating Net-Metering Policies," hosted by USAID Clean Power Asia and included speakers the Hawaii Natural Energy Institute as well as NREL. This presentation outlines grid codes in general, and IEEE Std 1547-2018 specifically, and discusses their adoption into interconnection requirements. Key capabilities, now enabled by IEEE Std 1547-2018, such as voltage regulation and frequency ride-through are described.

DER↗
DOE OSTI2022

Intersections of Disadvantaged Communities and Renewable Energy Potential: Analyses to Inform Equitable Investment Prioritization

Renewable energy development can bolster local economies through job creation, local tax revenues, and reduced energy costs; however, communities most in need of economic development and employment opportunities often see lower levels of renewable energy deployment. We sought to identify areas where indicators of disadvantaged communities intersect with high generation potential from cost- effective renewable energy opportunities. This presentation highlights the geospatial intersection of the technical potential and levelized cost of energy for three renewable technologies (residential solar, utility solar, and land-based wind) and three sociodemographic metrics (energy burden, unemployment, and employment in mining, quarrying, and oil and gas extraction). This research and the associated county-level data set are intended to inform national- and state-level energy-related assistance programs, economic development efforts, and infrastructure programs seeking to prioritize investments in disadvantaged communities.

disadvantaged communities↗
DOE OSTI2022

A multi-level load shape clustering and disaggregation approach to characterize patterns of energy consumption behavior

This study presents representative electrical load shapes, disaggregated to the end-use level, for over 5000 customer clusters across California’s residential, commercial, industrial and agricultural sectors. We developed a novel, multi-level load shape clustering approach for residential and commercial sectors leveraging interval meter data for over 350,000 California utility customers collected as a part of the Phase 4 California Demand Response (DR) Potential Study. The clustering approach allowed us to identify typical consumption patterns and categorize customers based on their daily load shape displayed throughout the year. For example, we were able to identify customers with particular energy technologies such as electric vehicles and rooftop solar, as well as building occupancy types such as restaurants, grocery stores and even unoccupied buildings, based solely on whole-building interval data. We then combined the load shape-based clusters with other customer information including building type, climate, geographical area, total consumption and low-income status, to create a set of customer clusters based on both demographics and usage patterns. Total cluster electricity demand was then disaggregated into a wide variety of end-uses using weather normalization and other publicly available end-use load shape datasets. The resulting disaggregated cluster load shapes will be released in anonymized form as part of the Phase 4 DR Potential Study. They will have wide-ranging applications in energy research and policy analysis, including estimation of energy efficiency (EE) and DR potential on the end-use level, time-dependent valuation of EE savings, building stock modeling, and developing customer targeting strategies for EE and DR programs.

Murthy, Samanvitha↗
DOE OSTI2024

Case Study: Increasing Solar Participation Among LIHEAP and WAP Clients in DC

The DC Department of Energy and Environment (DOEE) administers Solar for All, Low Income Home Energy Assistance Program (LIHEAP), and Weatherization Assistance Program (WAP). This case study discusses the partnerships between these programs to increase low-income participation in Solar for All.

community solar↗
DOE OSTI2020

A Framework for Optimal Placement of Rooftop Photovoltaic: Maximizing Solar Production and Operational Cost Savings in Residential Communities

Optimizing the placement of photovoltaic (PV) panels on residential buildings has the potential to significantly increase energy efficiency benefits to both homeowners and communities. Strategic PV placement can lower electricity costs by reducing the electricity fed from the grid during on-peak hours, while maintaining PV panel efficiency in terms of the amount of solar radiation received. In this article, we present a framework that identifies the ideal location of PV panels on residential rooftops. Our framework combines energy and environmental simulation, parametric modeling, and optimization to inform PV placement as it relates to and affects the entire community (in terms of both energy use and financial cost), as well as individual buildings. Ensuring that our framework accounts for shading from nearby buildings, different utility rate structures, and different buildings’ energy demand profiles means that existing communities and future housing developments can be optimized for energy savings and PV efficiency. The framework comprises two workflows, each contributing to optimal PV placement with a unique target: (a) maximizing PV panel efficiency (i.e., solar generation) and (b) minimizing operational energy cost considering utility rate structures for operational energy. We apply our framework to a residential community in Fort Collins, Colorado, to demonstrate the optimal PV placement, considering the two workflow targets. Here, we present our results and illustrate the effect of PV location and orientation on solar energy production efficiency and operational energy cost.

14 SOLAR ENERGY↗
DOE OSTI2024

Evaluating community solar as a measure to promote equitable clean energy access

Rooftop and community solar are alternative product classes for residential solar in the United States. Community solar, where multiple households buy solar from shared systems, could make solar more accessible by reducing initial costs and removing adoption barriers for renters and multifamily building occupants. Here we test whether community solar has expanded solar access in the United States. On the basis of a sample of 11 states, we find that community solar adopters are about 6.1 times more likely to live in multifamily buildings than rooftop solar adopters, 4.4 times more likely to rent and earn 23% less annual income. In this study, we do not find that community solar expands access in terms of race. These differences are driven, roughly evenly, by inherent differences between the two solar products and by policies to promote low-income community solar adoption. The results suggest that alternative solar products can expand solar access and that policy could augment such benefits.

14 SOLAR ENERGY↗
DOE OSTI2024

Solar Pathways in Federal Energy Assistance Programs: Expanding the Low-Income Home Energy Assistance Program (LIHEAP) and the Weatherization Assistance Program (WAP)

The U.S. Department of Health and Human Services Low-Income Home Energy Assistance Program (LIHEAP) and U.S. Department of Energy Weatherization Assistance Program (WAP) are federal programs to help low-income households reduce their energy costs. LIHEAP provides direct assistance to help households cover energy costs and stay connected to utility services, as well as weatherization and minor energy-related repairs, and WAP provides no-cost energy efficiency measures to reduce energy use and energy bills while also improving home comfort for income-qualified households. Across the U.S., states are implementing or considering solar energy as an eligible measure for LIHEAP and/or WAP funding, but the successful implementation pathways remain largely undocumented. This report fills that gap by analyzing states' LIHEAP and WAP annual plans, surveying administrators from LIHEAP grant recipients and WAP grantees about their challenges implementing solar or barriers to doing so, and conducting interviews and workshops with program administrators.

14 SOLAR ENERGY↗
DOE OSTI2021

Solar permitting, inspection, and interconnection cycletimes and requirements

Twenty three small-to-large residential, commercial, and industrial PV installers submitted project-level data for analysis, which included timestamps for major components of the permitting, inspection, and interconnection process as well as contract and installation dates. NREL calculated median timelines for these processes across the authorities having jurisdiction (AHJs) and utilities represented in the data. Also included are relevant permitting requirements for AHJs and interconnection process requirements for utilities. This dataset represents the underlying results shown in the Solar Time-based Residential Analytics and Cycle time Estimator (SolarTRACE) viewer. This dataset has been reviewed but errors may exist, and it may not be comprehensive. Errors in the sources (e.g., AHJ permitting requirements lists from data partners) may be duplicated in the dataset.

14 SOLAR ENERGY↗
DOE OSTI2024

Solar Pathways in Federal Energy Assistance Programs: Expanding Low Income Home Energy Assistance Program (LIHEAP) and Weatherization Assistance Program (WAP)

How can solar best fit within your LIHEAP or WAP activities? Come join NREL and learn about the various pathways and new resources available to help implement solar in low-income programs. Panelists will share results from a multi-year research project, including survey results on LIHEAP and WAP solar adoption across the United States. This session will highlight case studies from early implementers, key lessons learned and resources developed based on stakeholder feedback for interested organizations. Attendees can expect gain a better understanding of the perceived barriers and opportunities to solar implementation, including the importance of partner coordination and complementary funding sources, and the next steps for how to get started. Additionally, attendees will hear from a local implementer of solar in WAP about their program and process.

Colorado↗
DOE OSTI2020

Analysis of the Value Proposition of High-Efficiency, Multijunction Solar Modules for Residential Rooftop Installations

Utilizing detailed bottom-up models, we analyze the potential markets for high-efficiency photovoltaic modules in the United States. We first estimate the fraction of area-constrained residential rooftops that could benefit from increasing the availability of high-efficiency systems. We then model the impact of efficiency on installed system costs in these area-constrained scenarios. Finally, we explore the value proposition of high-efficiency, fixed-tilt micro-concentrator photovoltaic modules in a series of case studies of residential customers, modeling the levelized cost of energy, payback period, and annual bill savings. We find that efficiency can provide significant savings in installed system cost and improve value to the solar system owner. The improvement in value depends on location and the size of the rooftop, as well as the ability of a given technology to collect diffuse light and achieve low module costs.

14 SOLAR ENERGY↗