Transmission Interconnection Roadmap: Transforming Bulk Transmission Interconnection by 2035
Explore the source record for details and available documents.
Gorman, Will↗
SEARCH · Engineering Papers
Results for “interconnections”
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.
Small Hydropower Interconnections: Best Practices
Small hydropower projects have been the predominant source of capacity growth of U.S. hydropower for more than a decade, and they present the most cost-effective and environmentally permissible avenues for hydropower growth (DOE 2016; Johnson et al. 2018). However, interconnection to electricity distribution and transmission grids is a persistent barrier due to cost surprises and schedule overruns. As a culmination to research into the status and requirements of small hydropower interconnection across the United States, this paper presents the best practices for setting interconnection standards that can improve the process for small hydropower developers. As part of the analysis, the interconnection costs are compared between small hydropower, solar, and wind. The analysis of the small hydropower interconnection landscape across the United States was carried out by Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) with support from the U.S. Department of Energy Water Power Technologies Office. The research team was guided by a Technical Advisory Group (TAG) and gleaned data from publicly available sources, such as the HydroSource database (ORNL 2020) and interconnection queues hosted by utilities, balancing authorities, independent system operators (ISOs), and regional transmission organizations (RTOs). The results of this work are shared in a series of papers detailing the state of small hydropower in the United States (“Small Hydropower Interconnections: Small Hydropower in the United States”), the variety of state interconnection processes to connect power generators with the grid (“Small Hydropower Interconnections: State Interconnection Processes”), and an analysis of the interconnection processes (“Small Hydropower Interconnections: Analysis of Interconnection Processes”). In this, the final paper in the series, best practices for interconnection processes (“Small Hydropower Interconnections: Best Practices”) are identified from the solar energy and distributed wind energy industries that are transferrable to small hydropower development. This information will help overcome barriers to future small hydropower development.
13 HYDRO ENERGY↗
A review of United States energy-only generator interconnection service policy and considerations for reform
Grid interconnection has emerged as a significant obstacle to the development of new electricity resources. There is growing interest in energy-only interconnection, which is an interconnection service option meant to allow the interconnection of new generators without ensuring their energy deliverability during all hours through the transmission system to customers. This approach potentially avoids upfront congestion-related transmission upgrades but could increase curtailment risk. Interest in energy-only interconnection is shaped by incomplete understanding of how interconnection policy functions in different jurisdictions, a knowledge gap that makes it difficult to determine how energy-only interconnection might be better used or re-designed. In this paper, we provide a regulatory review of energy-only interconnection in U.S. interconnection policy and practice, identifying jurisdictions in which rules are close to -or farther from-the theoretical concept of energy-only interconnection service. We find substantial jurisdictional differences in how energy-only interconnection is implemented, driven by differences in resource adequacy frameworks, real-time transmission operations, and state-level procurement practices. U.S. regulators have preferred local jurisdictional flexibility over federal prescription of interconnection study methods and procedures, which also contributes to differences among regions. Such findings raise fundamental questions about whether competition policies in electricity markets should extend beyond spot energy markets and into more prescriptive guidelines around interconnection rules and market entry. This paper sheds light on tensions that energy-only interconnection raises in allowing generators to access the transmission system on an as available basis and discusses how controlling thresholds for congestion-related network upgrades may be a barrier to electricity market entry.
Gorman, Will↗
Generator Interconnection Costs to the Transmission System in non-ISO Balancing Authorities [Slides]
Electric transmission system operators—including Independent System Operators (ISOs), Regional Transmission Organizations (RTOs), and utilities—require proposed power plants to undergo a series of interconnection studies before connecting to the grid. These studies assess what transmission upgrades or new infrastructure may be necessary and assign the associated costs to the project. Lawrence Berkeley National Laboratory has compiled, aggregated, and cleaned interconnection cost data, originally for ISOs/RTOs, and now for five non-ISO Balancing Authorities: PacifiCorp, Bonneville Power Authority, Duke Energy Progress, Duke Energy Carolinas and Duke Energy Florida. Insufficient transparency in interconnection cost data may contribute to rapidly expanding interconnection queues, with active queue capacities tripling between 2020 and 2024 in the studied BAs. Most projects withdraw after receiving high interconnection cost estimates. Interconnection costs have increased since the early 2000s, with average costs for "complete" projects reaching $194/kW between 2018 and 2024. Active queue projects and withdrawn projects incur substantially higher costs, primarily due to rising network upgrade costs. Recent interconnection costs in non-ISO balancing authorities are higher than in ISO regions, potentially due to a greater willingness to pay among developers. Utility-scale solar, wind, and storage projects have interconnection costs that exceed those for natural gas. However, when focusing on projects that do not withdraw from the queue, the interconnection costs for these technologies are more similar to natural gas projects. Other key findings include: (1) Larger generation projects benefit from lower proportional interconnection costs, (2) capacity transmission service (NRIS) often requires additional network investments, and (3) projects with high network upgrade costs are often clustered geographically. The dataset includes results from 2,104 interconnection studies conducted between 2000 and 2024, covering projects that are operational, withdrawn, or still progressing through the study process. The Excel file contains (a) the complete project-level interconnection cost dataset, and (b) seven additional tabs summarizing cost metrics across dimensions such as time, market structure, cost category (point of interconnection vs. broader network upgrades), fuel type, service type (ERIS vs. NRIS), generator size, and geography.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Small Hydropower Interconnections: Small Hydropower in the United States
Small hydropower projects, which we define as generators below 20 MW in capacity have been the predominant source of hydropower growth over the past decade and create the most cost-effective and environmentally permissible avenues for new hydropower installation in the United States (DOE 2016; Johnson et al. 2018). Small hydropower developers across the United States have found that interconnecting these projects with the grid can be challenging due to unexpected costs and schedule overruns. Understanding the interconnection challenges and improving the process may allow more small hydropower projects to be successful. Noting these challenges, the U.S. Department of Energy Water Power Technologies Office enlisted Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) to investigate the small hydropower interconnection landscape across the United States. To begin to analyze the existing interconnection processes and challenges facing small hydropower, the state of small hydropower development in the U.S. must first be described to understand the characteristics of the industry. The first in a series, this paper presents the state of small hydropower projects in the U.S. to describe their type, location, and size based on data extracted from the HydroSource database (ORNL 2020). The following papers in the series will detail the variety of state interconnection processes to connect power generators with the grid (“Small Hydropower Interconnections: State Interconnection Processes”), analyze these interconnection processes (“Small Hydropower Interconnections: Analysis of Interconnection Processes”), and present best practices in interconnection processes (“Small Hydropower Interconnections: Best Practices”) that will help overcome barriers to future small hydropower development.
13 HYDRO ENERGY↗
Generator Interconnection Cost Analysis in the Midcontinent Independent System Operator (MISO) territory
Electric transmission system operators (ISOs, RTOs, or utilities) require new large generators seeking to connect to the grid to undergo a series of impact studies before they can be built. This process establishes what new transmission equipment or upgrades may be needed before a project can connect to the system and assigns the costs of that equipment. Berkeley Lab has collected interconnection cost data from interconnection studies for the Midcontinent Independent System Operator (MISO), representing nearly 50% of all projects requesting interconnection from 2010 to 2020. Project-level cost summary data are available for download on this page. We find: -Average interconnection costs have grown as the number of interconnection requests have escalated -Projects that have completed all required interconnection studies have the lowest cost compared to applicants still actively working through the interconnection process or those that have withdrawn. -Broader network upgrade costs are the primary driver of recent cost increase. -Potential interconnection costs for wind, storage, and solar are larger than for natural gas -Larger generators have greater interconnection costs in absolute terms, but economies of scale exist on a per kW basis. -Interconnection costs vary by location Berkeley Lab will publish a series of short analytical papers of generator interconnection costs to the transmission system for MISO, PJM, SPP, ISO-NE and NYISO, which you can find at https://emp.lbl.gov/interconnection_costs.
29 ENERGY PLANNING, POLICY, AND ECONOMY↗
Interconnection Cost Analysis in the PJM Territory
Electric transmission system operators (ISOs, RTOs, or utilities) require new large generators seeking to connect to the grid to undergo a series of impact studies before they can be built. This process establishes what new transmission equipment or upgrades may be needed before a project can connect to the system and assigns the costs of that equipment. Berkeley Lab has collected interconnection cost data from interconnection studies for the PJM Territory, representing nearly 86% of all new unique generators requesting interconnection from 2000 to 2022. Project-level cost summary data are available for download on this page. We find: -Average interconnection costs have grown as the number of interconnection requests have escalated -Projects that have completed all required interconnection studies have the lowest cost compared to applicants still actively working through the interconnection process or those that have withdrawn. -Broader network upgrade costs are the primary driver of recent cost increase. -Potential interconnection costs for wind, storage, and solar are larger than for natural gas -Larger generators have greater interconnection costs in absolute terms, but economies of scale exist on a per kW basis. -Interconnection costs vary by location Berkeley Lab will publish a series of short analytical papers of generator interconnection costs to the transmission system for MISO, PJM, SPP, ISO-NE and NYISO, which you can find at https://emp.lbl.gov/interconnection_costs.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Interconnection Cost Analysis in ISO-New England
Electric transmission system operators (ISOs, RTOs, or utilities) require new large generators seeking to connect to the grid to undergo a series of impact studies before they can be built. This process establishes what new transmission equipment or upgrades may be needed before a project can connect to the system and assigns the costs of that equipment. Berkeley Lab has collected interconnection cost data for 194 projects in New England from interconnection studies performed between 2010 and 2021. Project-level cost summary data are available for download on this page. We find: -Interconnection costs have grown over time, especially for projects that withdraw. -Interconnection costs are highest for onshore wind, followed by solar and storage. Natural gas and offshore wind projects tend to cost less to interconnect, in comparison. -Economies of scale exist for solar and possibly storage projects, but not for other resource types. -Wind and solar projects requesting capacity network resource interconnection service have higher interconnection costs, despite being evaluated using the same interconnection standard in the analyzed studies. -Low and high interconnection costs can be found throughout the ISO-NE footprint. -Costs are split fairly evenly between investments at the point of interconnection and within the broader network for active and withdrawn projects, while complete projects incur most costs at the point of interconnection.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Queued Up: 2025 Edition – Characteristics of Power Plants Seeking Transmission Interconnection As of the End of 2024 [Slides]
Electric transmission system operators (ISOs, RTOs, or utilities) require proposed power plants seeking to connect to the transmission grid to undergo a series of impact studies before they can be built. This process establishes what new transmission equipment or upgrades may be needed before a project can connect to the system and assigns the costs of that equipment. The lists of projects in this process are known as “interconnection queues”. In collaboration with interconnection.fyi, Berkeley Lab compiled, aggregated, and cleaned interconnection queue data from >50 transmission grid operators (7 ISO/RTOs and 49 non-ISO balancing areas), which collectively represent ~97% of currently installed U.S. electric generating capacity. The dataset includes requests submitted to queues through the end of 2024, and only includes requests seeking to connect to the transmission grid (not distribution-connected or behind-the-meter projects). The files below include both a PDF report and an Excel data file. The PDF report analyzes interconnection data and metrics through the end of 2024. The Excel data file includes (a) the full project-level interconnection queue dataset through 2024, (b) a codebook (data dictionary) describing each data field, and (c) 35 additional tabs featuring tables summarizing a range of interconnection metrics. Key highlights from the Queued Up: 2025 Edition (featuring data through 2024) include: • As of the end of 2024, there were ~10,300 projects actively seeking grid interconnection in the U.S., representing 1,400 GW of generation and approximately 890 GW of storage. • Historic withdrawal rates alongside relatively fewer new requests resulted in a 12% decrease in total active queue volume compared to the prior year. • Active natural gas capacity (136 GW, +72% year-over-year) increased in 2024, while solar (956 GW, -12%), storage (890 GW, -13%), and wind (271 GW, -26%) capacity decreased. • 408 GW of capacity already has a draft or executed interconnection agreement (IA) but has not yet reached commercial operations. • The time projects spend in queues before reaching COD is increasing. For the regions with available data, the median duration from IR to COD has doubled from <2 years for projects built in 2000-2007 to over 4 years for those built in 2018-2024. • Ultimately, most of this proposed capacity will not be built. Only 13% of capacity that submitted interconnection requests from 2000-2019 had reached commercial operations by the end of 2024; 77% of that capacity had been withdrawn and 10% was still active. • FERC Order 2023 and various other reforms are being implemented. These are important measures to reduce interconnection bottlenecks and enhance grid system reliability, but it is too early to measure and assess their full impact. • New additions for the 2025 edition include: (a) additional detail on data processing and gaps; (b) updates on interconnection reforms; (c) new analysis on interconnection agreements, and more.
24 POWER TRANSMISSION AND DISTRIBUTION↗
A Guide to Updating Interconnection Rules and Incorporating IEEE Standard 1547
The intent of this paper is to support local authorities in adopting the most current technical requirements for interconnecting distributed energy resources (DERs) to the electric distribution system as specified in the Institute of Electrical and Electronics Engineers Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces (IEEE Std 1547-2018). To create interconnection rules that successfully address policy goals, market trends, and technical requirements, state regulators need to be well informed of DER integration considerations. Interconnection processes and technical issues often overlap; the two are not easily segregated, and they are often considered and evaluated concurrently within the context of interconnection rulemaking. Accordingly, this paper addresses both the technical issues and related process considerations. A lack of uniform and transparent procedures for addressing interconnection rule changes can result in implementation issues or inefficiencies, such as unclear, lengthy, and complicated interconnection rules that can increase distributed generation "soft costs" (i.e., non-hardware costs). This can further delay the deployment of DERs and jeopardize time-constrained national and state policy goals, such as renewable energy targets, or limit participation in emerging techno-economic trends. Additionally, misconstructed interconnection rules are at risk of becoming mired in stakeholder conflicts. This guide addresses the concerns of electric service regulators from both the process and technical standpoints by presenting a structured, step-by-step approach to developing and updating existing interconnection rules. In this document, the process of developing and updating interconnection rules is subdivided into three steps: (1) determining the context (stakeholders and major drivers); (2) developing the rule, including updating technical requirements; and (3) maintaining and revising the rule over time.
14 SOLAR ENERGY↗
Use of Operating Agreements and Energy Storage to Reduce Photovoltaic Interconnection Costs: Technical and Economic Analysis
This report presents an analytical methodology to identify alternative options to manage interconnection costs and streamline interconnection timelines for distribution system-connected photovoltaic (PV) systems not co-located with load. Specifically, the report details the methodology and results of an analysis that: 1. Identifies potential grid violations that would be induced by a PV system requesting interconnection to a distribution circuit; 2. Identifies multiple technically viable options for mitigating the potential violations, including infrastructure upgrades, downsizing the PV system size, curtailment of PV, and addition of battery energy storage; 3. Defines the required technical operating parameters of the system in order to mitigate all potential violations (the "Operating Envelope"); 4. Compares the economics of each option, from the PV developer's perspective. The analysis supports the ongoing evolution of interconnection standards for combined PV and energy storage systems by providing a methodology to define allowable maximum export limits during each hour. The methodology presented could be used by utilities as part of the interconnection study process, to inform negotiations with DER developers and the drafting of mutually acceptable interconnection agreements. The resulting technical operating parameters could be included as part of the interconnection service agreement (ISA) between the system owner and the utility company. The companion report to this analysis, Gill et al. (2022), details the envisioned framework for the implementation of the technical operating parameters.
14 SOLAR ENERGY↗
Generator Interconnection Cost Analysis in the Southwest Power Pool (SPP) Territory
Electric transmission system operators (ISOs, RTOs, or utilities) require new large generators seeking to connect to the grid to undergo a series of impact studies before they can be built. This process establishes what new transmission equipment or upgrades may be needed before a project can connect to the system and assigns the costs of that equipment. Berkeley Lab has collected interconnection cost data for 845 projects from interconnection studies for the Southwest Power Pool (SPP) Territory. The studies were performed between 2002 and 2023 and include all of the most refined cost estimates available. Project-level cost summary data are available for download on this page. We find: -Project-specific interconnection costs can differ widely. -Average interconnection costs are stable for projects that complete all interconnection studies but have escalated for those that withdraw. -Broader network upgrade costs are the primary driver of recent cost increases, especially for withdrawn projects. -Potential interconnection costs of all solar and wind requests have been greater than those of storage and natural gas projects. -Economies of scale exist for completed wind and solar projects but not for other fuel types or withdrawn projects. -Interconnection costs vary by location. Berkeley Lab publishes a series of short analytical papers of generator interconnection costs to the transmission system for MISO, PJM, SPP, ISO-NE and NYISO, which you can find at https://emp.lbl.gov/interconnection_costs.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Energy Infrastructure Futures: A Multiscale Evaluation of Projected Power Plant Siting Across the Western Interconnection
Energy Infrastructure Futures: A Multiscale Evaluation of Projected Power Plant Siting Across the Western Interconnection Description This dataset contains input and output data for the manuscript Mongird, K. et al. (under review) titled "Energy Infrastructure Futures: A Multiscale Evaluation of Projected Power Plant Siting Across the Western Interconnection". Input data corresponds to gridded spatial siting attributes that are necessary to conduct a random forest machine learning analysis of siting feature importance. Output data includes SHAP feature analysis outputs, and classification report values. For data on power plant siting results referred to in the manuscript, please refer to the CERF: IM3 Projected Western US Power Plant Locations data download page. The downloadable data includes values for eight different future scenarios for the Western US. The scenarios include combinations of two Shared Socioeconomic Pathways (SSP3 and SSP5) with four high-resolution climate projections specific to the United States (see, https://tgw-data.msdlive.org/). These climate projections include "hotter" and "cooler" variants for two Representative Concentration Pathways (RCP4.5 and RCP8.5). The resulting eight simulations are: rcp45cooler_ssp3 rcp45cooler_ssp5 rcp45hotter_ssp3 rcp45hotter_ssp5 rcp85cooler_ssp3 rcp85cooler_ssp5 rcp85hotter_ssp3 rcp85hotter_ssp5 Technical Information The dataset includes two sets of data files: (1) CERF gridded siting parameters and (2) Feature analysis outputs and classification reports. All downloadable data is in csv file format. Files with x/y coordinate information use the Albers Equal Area Conic projection (ESRI:102003). 1. CERF Gridded Siting Parameters This directory provides a balanced sample of gridded CERF siting parameters data for eight different scenarios for the Western US through 2055, seven different technologies, and eight timesteps. This data serves as input to the feature analysis. It contains the following parameters. region_name - name of region (i.e., state) sited - binary value representing whether the grid cell received a siting of that technology type (1=True) rcp - binary value representing scenario resource concentration pathway (0 = RCP4.5, 1 = RCP8.5) ssp - binary value representing scenario shared socioeconomic pathway (0 = SSP3, 1 = SSP5) climate - binary value representing cooler (0) or hotter (1) GCM forcing tech_name - generation technology name sited_year - year that values correspond to transmission_cost - cost of transmission interconnection pipeline_cost - cost of natural gas pipeline interconnection interconnection_cost - total interconnection cost (sum of transmission cost and gas pipeline cost) lmp - associated locational marginal value ($/MWh) associated with the grid cell, timestep, scenario, and technology xcoord - x-coordinate of location ycoord - y-coordinate of location 2a. Feature Analysis Output The dataset includes the feature analysis shap output for locational marginal price and interconnection cost. It contains the following parameters. technology - generator technology name scenario - name of scenario feature - name of feature, either locational_marginal_price or interconnection_cost value - the mean of absolute value of SHAP values for given feature 2b. Feature Analysis Classification Report This download includes the classification report associated with each random forest model. The dataset contains the following parameters. technology - generation technology name scenario - name of scenario test - one of precision (the proportion of predicted positives that are actually correct), recall (the proportion of actual positives that were correctly identified), f1-score (the harmonic mean of precision and recall) 0.0 - value of test for classification of 0 (grid cell not chosen for siting) 1.0 - value of test for classification of 1 (grid cell chosen for siting) accuracy - accuracy of model (i.e., fraction of all predictions that were right) macro avg - Simple average of test values for all classes weighted avg - Weighted average of test values for all classes, weighted based on Acknowledgment IM3 is a multi-institutional effort led by Pacific Northwest National Laboratory and supported by the U.S. Department of Energy's Office of Science as part of research in MultiSector Dynamics, Earth and Environmental Systems Modeling Program. License This data is made available under a CCBY4 License Disclaimer This material was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. PACIFIC NORTHWEST NATIONAL LABORATORYoperated byBATTELLEfor theUNITED STATES DEPARTMENT OF ENERGYunder Contract DE-AC05-76RL01830
Mongird, Kendall [Pacific Northwest National Labor↗
Study of interconnect errors, network congestion, and applications characteristics for throttle prediction on a large scale HPC system
Today’s High Performance Computing (HPC) systems contain thousand of nodes which work together to provide performance in the order of petaflops. The performance of these systems depends on various components like processors, memory, and interconnect. Among all, interconnect plays a major role as it glues together all the hardware components in an HPC system. A slow interconnect can impact a scientific application running on multiple processes severely as they rely on fast network messages to communicate and synchronize frequently. Unfortunately, the HPC community lacks a study that explores different interconnect errors, congestion events and applications characteristics on a large-scale HPC system. In our previous work, we process and analyze interconnect data of the Titan supercomputer to develop a thorough understanding of interconnects faults, errors, and congestion events. In this work, we first show how congestion events can impact application performance. We then investigate application characteristics interaction with interconnect errors and network congestion to predict applications encountering congestion with more than 90% accuracy.
97 MATHEMATICS AND COMPUTING↗
Thermomechanical fatigue resistance of low temperature solder for multiwire interconnects in photovoltaic modules
Novel interconnect technologies leveraging low melting temperature solders, such as multiwire interconnects, are being deployed in photovoltaic (PV) modules for improved reliability through interconnect redundancy and lower thermal loads during interconnection and lamination. However, the equivalency of standardized accelerated testing to field conditions has not yet been established for these emerging technologies. In this study, the thermomechanical fatigue resistance of low temperature solder alloys is investigated and compared to that of conventional SnPb to assess the acceleration behavior of these alloys. While InSn is shown to have sufficient thermomechanical fatigue resistance on the order of that of SnPb, these results indicate Sn–Bi alloys may have poor thermomechanical fatigue resistance at field conditions. The results also show that Sn–Bi alloys have thermal cycling acceleration factors of less than one. This indicates that the standardized accelerated thermal cycling test, such as that in IEC 61215, will produce misleading results for Sn–Bi alloys and that unique testing is required for this PV module architecture. Though accelerated thermal cycling may be a meaningful qualification test for SnPb solder joints, these results suggest that mechanical loading may be a more appropriate test for Sn–Bi multiwire interconnects. This is due to the distinct processing and geometry of multiwire interconnects which may allow for mechanical, rather than strictly metallurgical interconnections.
14 SOLAR ENERGY↗
A Combined Computational and Mathematical Analysis of Interconnect Fatigue Potential in Photovoltaic Modules
A finite element model of a 60-cell monocrystalline silicon glass-polymer photovoltaic module was simulated with ±1.0 kPa and ±2.4 kPa loads applied to the glass to calculate the deformation under load. Cell-to-cell displacements were used to approximate interconnect strain and stress. A mathematical fatigue cycle life relation was fitted to data for the interconnect material (copper), to generate a life prediction at each interconnect location based on the local stress means, reversal extents, and amplitudes. Interconnect stress was found to be significantly asymmetric about zero despite symmetric positive and negative module loads due to laminate thickness offsets about the neutral plane and the effects of module framing. Cycle life results indicated that interconnect fatigue failure was unlikely to occur over a 30-year lifetime of conservative wind and snow load cycles since the typical cell design feature of leaving some unconstrained length between the cell edge and first solder pad increases the effective gauge length and decreases the stress levels below the material endurance limit. Follow-up analyses found that 3.6 mm and 6.4 mm were the minimum unconstrained lengths required to survive the assumed lifetime of wind and snow cycles, respectively, confirming that typical industrial module constructions with 8–15 mm unconstrained lengths should survive conservatively. Notably, large magnitude, low-cycle snow loading was consistently the limiting factor requiring a longer unconstrained interconnect length. Finally, insights and workflows from this study inform module interconnection design limits for survival against mechanical fatigue in deployment environments.
14 SOLAR ENERGY↗
R3IT, Rapid Rural Resilient Interconnection Toolkit, Final Technical Report
Utilities nationwide are beginning to experience multiple solar interconnection requests per day. This request volume will soon overwhelm utility engineers, especially at smaller utilities which serve the majority of the landmass of the United States. In this project, we developed open-source software tool that automates the interconnection approval process and removes 80% of the time required to approve an interconnection and hence allow more solar to be quickly and safely integrated with the grid. This software is accompanied by a guidebook detailing interconnection best practices and utility lessons learned. Competing solar interconnection software is extremely expensive at ten times the cost of typical distribution engineering tools, it’s closed source which makes it hard to integrate into utility workflows, and it doesn’t address the hardest power flow modeling challenges of interconnection screening. Our solution was built built with our utility partners who are already experiencing multiple interconnection requests per day and integrates best practices from our past work with DOE and the cooperative community on solar integration. The resulting free and open-source solution has been disseminated through our media channels and conferences that engage over 1,900 utilities nationwide.
14 SOLAR ENERGY↗
Working With Your Utility Series: Interconnection Basics
This training provided information on interconnection basics for federal agencies developing distributed energy projects. Considerations covered included: Understanding interconnection processes and timelines, interconnection siting considerations, technology-specific interconnection issues, and interconnect agreements. This webinar is the first in a multi-part series on working with electric utilities to develop distributed energy projects on federal sites.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗