Recent lbnl_et items

An Exploratory Investigation of the Experience of Visible Wind Turbines

Fri, 30 Oct 2026 00:00:00 +0000

Wind turbines are normally the largest structures in the landscape, yet little is known about how they are experienced. Most studies of wind turbines focus on their scenic impact and represent them using visualizations. However, scenic judgments of wind turbines by different viewers can be highly variable and require higher-order cognition. In addition, recent research has called into question the validity of using visualizations to assess very large structures, such as wind turbines. This study explores the more intuitive perceptions of wind turbines, specifically the sense of looming and visual prominence of 35 individual turbines and the sense of looming and the feeling of being surrounded by wind farm turbines at nine viewpoints. Changes in scenic quality and fit with the landscape prior to the wind farms are also rated. The results show that the more intuitive perceptions have higher reliability. These perceptions are affected by turbine exposure, proximity, and extent, which...

Missing the mark: Avoiding community misengagement in large-scale solar development

Fri, 30 Oct 2026 00:00:00 +0000

Scholars have long argued the need for increased community engagement around large-scale solar (LSS) development in the United States (US). Despite this call, meaningful engagement processes remain rare, both because they are often not statutorily required and because a range of actors, including state and federal policy-makers, renewable energy developers, local officials, landowners, and nearby residents disagree about the need for as well as the intended goal of such processes. This disagreement has led to dramatic policy shifts around engagement and fostered processes that are insular, instrumental, abbreviated, and often focused on achieving a single objective: either the termination or approval of a LSS project. Here we work to distinguish this form of engagement, which we define as misengagement, from a more meaningful form of engagement, which has as its goals transparency, accessibility, and fairness as well as expanding the number and specificity of the perspectives,...

ICE Calculator 2 Initiative: Customer Interruption Costs for Select National Rural Electric Cooperative Association (NRECA) Members

Thu, 29 Oct 2026 00:00:00 +0000

This report presents findings from the latest outreach effort to update the Interruption Cost Estimate (ICE) Calculator. The research team surveyed residential and non-residential members of 18 electric cooperatives across three U.S. regions (Southeast, Great Plains/Upper Midwest, and Intermountain West). The research was conducted by Resource Innovations, the National Rural Electric Cooperative Association, and Lawrence Berkeley National Laboratory between February and December 2025. The team collected residential and non-residential survey responses using a rigorous willingness-to-pay methodology for households and direct cost measurement for businesses, examining interruption costs across a range of power interruption durations. Results show that interruption costs rise substantially with duration, but at a decreasing rate: residential members reported costs of $2 for a single momentary interruption up to $54 for a single 24-hour interruption, while non-residential members...

Permit outcomes and timelines: Comparing state and sub-state permitting authorities for large-scale energy facilities

Wed, 28 Oct 2026 00:00:00 +0000

Permitting reform, shaped by local and state governance, could eliminate unnecessary administrative burdens that slow the development of new electricity generation or increase its cost. However, the duration and outcomes of the permitting process are not well studied, especially for locally permitted projects, which are the standard for many parts of the U.S. Analyzing data across 29 states and more than 400 counties finds clear evidence that local (county or sub-county) permitting authorities move through the permitting process almost twice as fast, at near 200 days, as state-level authorities when permitting large-scale wind and solar projects. Additionally, there is a roughly 3x difference in permitting speed between the fastest and slowest states for both state and local permitting decisions. Further, more than 87% of state-level processes resulted in a granted permit, and 93% of sub-state-level processes, implying a high degree of application success.

Consist: Provenance-Aware Caching and Queryable Provenance for Scientific Workflows

Wed, 28 Oct 2026 00:00:00 +0000

Consist: Provenance-Aware Caching and Queryable Provenance for Scientific Workflows

Estimating Kinetic Parameters from the Impedance Response of Proton-Exchange-Membrane Fuel Cells Using Continuum Models

Tue, 27 Oct 2026 00:00:00 +0000

A mathematical framework for simulating the impedance response of a proton-exchange-membrane fuel cell (PEMFC) was developed to provide insight into the coupled physics and chemistry that influence observed spectra. The model was based on a cell-level continuum model that was linearized and represented in the frequency domain, which allowed for the accounting of coupled transport in a PEMFC and the simulation of full spectra in seconds. Good agreement was observed between experimental and simulated polarization and impedance data. Consistency between steady-state and frequency-domain continuum models was confirmed, which allowed for the extraction of kinetic information from the experimental impedance spectra. The model framework was used to estimate contributions associated with ohmic, charge-transfer, and transport resistances, which was shown to align with power-loss voltage breakdown analyses of steady-state simulations. A proposed equivalent-circuit model facilitated estimates...

Delivering Demand Flexibility and Grid-Edge Resources at Scale: Analysis of Experiences Across U.S. Jurisdictions

Thu, 22 Oct 2026 00:00:00 +0000

Significant load growth from data centers, industrial loads, and customer technology adoption is driving increased attention to solutions, such as demand flexibility (DF), that can enable new loads while managing existing capacity constraints. A growing body of literature has examined the potential and value of DF to meet grid and customer needs, as well as the associated reliability and affordability benefits. However, the implementation of DF and grid-edge resources (GER) programs can face a range of challenges and barriers. This study provides an up-to-date analysis of issues affecting DF and GERs identified in recent utility regulatory filings across a sample of U.S. jurisdictions (California, Maine, North Carolina, Ohio, Oregon, and Wisconsin). LBNL performed a systematic review of regulatory proceedings and other state actions related to DF and GERs to identify utility, commission, or state issues affecting implementation. The analysis identified three categories to...

Performance of Power over Ethernet DC Distribution

Thu, 22 Oct 2026 00:00:00 +0000

The U.S. General Services Administration (GSA) and the U.S. Department of Energy sponsored a field and bench-scale evaluation of a Power over Ethernet (PoE) direct-current (DC) distribution lighting system at GSA’s Workplace Innovation Lab (WIL) in Washington, DC, with supplemental testing at Lawrence Berkeley National Laboratory (LBNL). Cisco provided the PoE-based DC lighting and controls platform for assessment. The project topic generally examines how DC distribution and combined power-and-data networks can help move commercial buildings from today’s fragmented AC-to-DC device-by-device model toward streamlined DC-centric architectures that enable granular monitoring, flexible IT-style deployment, and intelligent “plug-and-play” integration of lighting, HVAC, security, and other Internet of Things (IoT) devices.

Unlocking Grid Flexibility: Understanding Challenges for Scaling Aggregated Demand Flexibility for the Distribution System

Wed, 21 Oct 2026 00:00:00 +0000

Accelerating load growth from domestic manufacturing and data center development is increasing pressure on distribution systems across the United States. Traditional infrastructure upgrades face long lead times and rising costs. Demand flexibility (DF) from aggregated distributed technologies can help defer costly infrastructure upgrades and address localized constraints to the energy system. This aggregated DF, operated by utilities or other organizations, can shift or reduce loads to provide reliability and alleviate costs at the distribution and bulk system levels, supporting affordability for customers. Despite recent growth in deployment of such demand flexible measures, they remain underutilized as a distribution system resource. This paper examines how aggregators can address distribution-level grid constraints and identifies the institutional and economic barriers limiting scale. Drawing on literature review and interviews with over 15 aggregators and other market participants,...

Outcomes and timelines for state-based energy facility permitting in the United States

Wed, 21 Oct 2026 00:00:00 +0000

Permitting is a critical process shaping the pace, scale, impacts, cost, and distribution of energy supply. This study documents recent timelines and outcomes of state-based permitting processes for wind and solar projects across 19 states in the U.S. Ninety percent of projects obtained permit approval and most within a year or so of entering the process. State-level policies for permitting vary considerably, and two states (KY, MS) have substantially shorter average timelines than other states in our sample. Additional research is needed to identify factors responsible for the outcomes and timelines and clarify how different permitting regimes influence important factors such as public participation in permitting or the environmental impact of projects.

Permitting and siting of wind and solar in Massachusetts: processes, timelines, and outcomes

Wed, 21 Oct 2026 00:00:00 +0000

Permitting reform, shaped by local and state governance, could eliminate unnecessary administrative burdens that slow the development of new electricity generation. However, the permitting process or duration is not well known, especially for locally-permitted projects, which are the standard in the U.S. Northeast and the most common permitting type in the United States. Here, we create an original data set of locally-permitted wind and solar energy projects in Massachusetts to document those timelines. We find that, on average, the permitting duration lasted 250 days, and this duration has increased over time. Permitted and lower capacity projects were associated with shorter permitting duration while canceled and larger capacity projects are associated with longer permitting duration. The results represent the first attempt to calculate permitting speed for locally-permitted wind and solar energy projects at a time when several states are reforming permitting policies, including...

Near‐Micron Single‐Crystalline Mn‐Rich Cathodes With Exceptional Cycling Stability

Wed, 21 Oct 2026 00:00:00 +0000

ABSTRACT Achieving high‐energy‐density and long‐term cycling stability in Mn‐redox‐based cathodes is a critical step toward advancing Ni‐ and Co‐free Li‐ion chemistries to diversify supply chains and lower battery costs. Here, we demonstrate an unusually high performance benchmark for Mn‐redox cathodes using near‐micron single‐crystalline δ‐phase cation‐disordered rocksalt (δ‐DRX), derived from Mn‐rich DRX, delivering ≈640 Wh kg −1 with ≈97% capacity retention over 400 cycles. The very high energy density and cycle life were achieved by using a high Mn content, to suppress oxygen redox activity, and careful control of the synthesis parameters to tune single crystal particle size. Using high‐throughput automated electron microscopy, we identify interparticle compositional heterogeneity present in the early stage of phase‐pure DRX formation as the origin of orthorhombic LiMnO 2 impurity formation during cooling, a finding that rationalizes the long high‐temperature dwell times...

ACES. VII. Compact Continuum Source Catalog of the Central Molecular Zone

Tue, 20 Oct 2026 00:00:00 +0000

The central molecular zone (CMZ) resides in the inner few hundred parsecs of our Galaxy, and despite being the largest reservoir of dense molecular gas in the Milky Way, it has a relatively low present-day star formation rate (SFR) of ∼0.08 M⊙ yr−1. Continuum and spectral line observations from the Atacama Large Millimeter/submillimeter Array (ALMA) CMZ Exploration Survey (ACES) provide the first full-coverage, high-resolution map of the inner 200 pc of the CMZ at 3 mm. In this paper we present the ACES catalog of compact continuum sources, the most complete catalog of potential sites of star formation in the CMZ to date. Using an automated dendrogram-based source extraction procedure in combination with a by-eye morphological classification scheme, we produce a “full” catalog of 1735 detections in total. Additionally, we use spectral index measurements to generate a “filtered” catalog of 567 sources with minimal contamination from nonthermal filaments and extended free–free emission....

Beescape and BeeSpatial: Making multi-scale environmental indicators of bee habitat accessible across audiences

Tue, 20 Oct 2026 00:00:00 +0000

Pollinators, especially bees, provide a key ecosystem service by facilitating flowering plant reproduction and crop production. Supporting bee populations requires an understanding of land cover, foraging and nesting resources, insecticide loading and toxicity, and climate trends in the landscape. However, datasets necessary for assessing bee habitat quality are not conveniently located, interoperable, or readily accessible. Further, stakeholders have differing needs and technical capacities. We developed two complementary web applications that tailor access to bee habitat indicators for a large geographical region, the conterminous United States: 1) Beescape provides bee habitat quality indicators at user-selected locations and is designed from feedback by its main intended users: beekeepers, growers, gardeners, scientists, and conservationists. Beescape enables dynamic visualizations of landscape conditions impacting bees to support bee colony and habitat management and general...

Analyzing land characteristics associated with historical large-scale solar photovoltaic deployment in the united states

Tue, 20 Oct 2026 00:00:00 +0000

Large-scale solar (LSS) deployment has accelerated rapidly across the United States, yet comprehensive understanding of its siting patterns remains limited. Here, we present a national-scale geospatial assessment of land characteristics converted for LSS development and apply statistical analyses to evaluate whether installations are disproportionately concentrated within specific land types. We find that siting patterns are strongly correlated with high solar irradiance, underscoring the role of resource quality in shaping deployment decisions. LSS projects are disproportionately concentrated on agricultural lands and shrubland. Within agricultural areas, installations predominantly occur on croplands and are strongly associated with irrigated systems. Notably, more than 90% of projects are deployed on agricultural land with Productive, Versatile, and Resilient (PVR) index values of land quality exceeding the national median. These findings highlight the need for strategic siting...

Assessing consumer choice projections in energy system models: A heat pump case study

Tue, 20 Oct 2026 00:00:00 +0000

Consumer adoption of heat pumps is a critical component of uncertainty in load growth forecasts, yet projections of heat pump adoption are rarely a focus of deeper investigation. This paper conducts a case study assessment of the structure, outputs, and performance of a model of U.S. residential heat pump adoption that has been used in multiple buildings sector potential studies and cross-sectoral energy system modeling exercises. The assessment includes model sensitivity testing based on a review of key factors in the heat pump adoption literature. Model projections across a range of scenarios show substantial regional variation in projected heat pump sales shares and sensitivity to input adjustments, with sales shares generally higher and less sensitive to input changes in warmer regions with high existing heat pump penetration, and generally lower and more sensitive in colder regions with a large installed base of fossil- and/or resistance-based heating equipment. Model benchmarking...

A practical introduction to electrochemical atomic force microscopy and scanning tunneling microscopy

Mon, 19 Oct 2026 00:00:00 +0000

Directly monitoring the structure and evolution of an electrode surface during reaction provides uniquely powerful insight into interfacial processes. Electrochemical atomic force microscopy (EC-AFM) and Scanning Tunneling Microscopy (EC-STM) have therefore become essential tools for linking potential-controlled surface transformations to macroscopic current and product outcomes. In EC-AFM, surface features are measured from the deflection of a typically laser-tracked cantilever, enabling imaging of metals, semiconductors, and insulators in liquid electrolytes. By selecting appropriate probes and operating modes, EC-AFM maps topography together with complementary channels such as mechanical response, friction, and local electrical contrast, offering a multi-parametric view of the electrified interface during processes such as film formation, corrosion, gas evolution, and electrodeposition. By contrast, EC-STM measures the tunneling current between a conductive tip and a conductive...

A simplified approach to energy-water modeling for controlled environment agriculture

Mon, 19 Oct 2026 00:00:00 +0000

An increasingly implemented alternative to outdoor farming, controlled environment agriculture (CEA) ensures reliable food production despite volatile growing conditions such as drought, flooding, and extreme temperatures. CEA can bolster local food production and revenue, promoting food resilience; however, the high energy and, in some cases, water demand required to optimize indoor environments for crop growth is a notable barrier to adoption. Understanding the resource consumption of CEA facilities is crucial to the sustainable growth of this sector, but existing models tend to be proprietary, limited in scope, or require detailed design data. To address this issue, we propose a simplified, flexible model (CEAEstA) that integrates fundamental lighting, heating, cooling, and evapotranspiration principles to estimate energy and water demand. The model is designed to be accessible for early-stage feasibility assessments, allowing stakeholders to evaluate sustainability trade-offs...

Interregional transmission and resource adequacy: an empirical analysis of peak demand coincidence and power flows in the United States, 2016–2024

Mon, 19 Oct 2026 00:00:00 +0000

There is growing interest in leveraging interregional transmission as a resource adequacy (RA) asset as the U.S. electric grid faces challenges from extreme weather, load growth, and a changing generation mix. However, empirical evidence of how transmission functions during periods of system stress remains limited. This paper addresses that gap by analyzing nine years of historical peak demand patterns and interregional power flows across 18 continental U.S. transmission planning regions from 2016–2024. We identify RA-critical periods based on peak net load and assess when regions experience these peaks at simultaneous or opposite times. We then analyze actual power flows during these high-stress periods to evaluate how effectively interregional transmission was used to support stressed regions. Our results show substantial geographic variation in the theoretical potential for transmission to provide RA support. Furthermore, realization of this potential is often poor: approximately...

Disentangling Catalytic Activity and Film Conductivity Reveals Temporally Decoupled Catalyst Evolution and Conductivity Artifacts

Fri, 16 Oct 2026 00:00:00 +0000

Abstract Catalytic activity and electrical conductivity are critical to the performance of electrocatalysts and electrochemical devices, yet their combined assessment under operating conditions remains challenging. Here, we introduce operando Fourier-transform electrochemical source–drain impedance spectroscopy (FT-ESDIS), which simultaneously measures catalyst-film conductivity and charge-transfer resistance (Rct) with high temporal resolution at high current densities. During Fe incorporation into nickel (oxy)hydroxide (NiOxHy), FT-ESDIS revealed that catalytic activation and charge transport properties evolve on distinct time scales, demonstrating that activity alone cannot capture catalyst-layer evolution during operation. At higher overpotentials, nickel-containing (oxy)hydroxides (Ni(Fe)OxHy) showed an abrupt apparent conductivity increase upon oxidation, with conductivity remaining nearly unchanged thereafter, whereas iron (oxy)hydroxide (FeOxHy) exhibited a gradual increase...

Cost, emissions, and material flow implications of designing electric vehicle components for recyclability

Wed, 14 Oct 2026 00:00:00 +0000

Abstract The electric vehicle (EV) industry is growing rapidly; however, compared to conventional automobiles, the increased weight of EVs contributes to their more limited range. To reduce total EV weight, higher-end vehicles use materials such as aluminum, which are more costly and energy-intensive than steel. This presents a challenge to the industry: there is a need to transition toward both lightweighting and material circularity. Improved materials are needed not only to reduce weight and improve efficiency but also to facilitate reclamation of metals and polymers from end-of-life vehicles. This study provides and demonstrates a framework for evaluating lightweight polymer alternatives for conventional EV components from a circularity perspective. The study identifies replacement materials for bumpers, door panels, interior consoles, and battery enclosures by evaluating material properties, environmental impacts, and economic metrics. Next, the study explores the battery...

Quantifying Methane Emissions from Oil Fields in the Central Valley of CA

Tue, 13 Oct 2026 00:00:00 +0000

Abstract In 2024, California was the eighth-largest producer of crude oil in the U.S. by volume with ∼50,000 active wells. Working with the California Energy Commission, we measured methane (CH4) emissions from 172 actively producing oil wells (219 total observations with 47 repeat measurements) either with or without casinghead gas collection systems (GCS) in two oil fields near Bakersfield in Kern County. We also measured benzene (C6H6) emissions at a subset of wells to assess C6H6 to CH4 ratios. The mean mass-based ratio for C6H6:CH4 was 7.8 × 10–7 with a mean benzene emission rate of 0.9 mg h–1. Wells with an open-ended line (OEL) emitted ∼100-fold more methane on average than wells with a GCS: 1.26 kg h–1 and 0.01 kg h–1, respectively. The prevalence of wells with a GCS rose sharply with increasing oil and gas production, rising from 36% for wells producing <2 barrels of oil equivalent per day (boed) to 97% for wells producing ≥15 boed. The top 5.7% highest-emitting wells...

HeatShift-HP: A Techno-Economic framework for assessing heat pump load shifting under dynamic tariffs and grid fees

Tue, 13 Oct 2026 00:00:00 +0000

Rapid growth of electric demand combined with increased penetration of intermittent power sources increases the value of flexible electric heating, but the techno-economic role of central hot-water storage under realistic tariffs remains unclear. This paper introduces HeatShift-HP, an open-source Python/Modelica co-simulation workflow. The framework couples a generic air-to-water heat pump and a stratified storage tank Functional Mock-up Unit with a supervisory rule-based controller and time series of weather, heating load, and end-user electricity prices. The framework targets plant-side flexibility and varies specific tank volume, nominal supply and return temperatures, heat-pump sizing, controller settings, and tariff variants, including a price-responsive boosting strategy constrained by a cost-neutral coefficient of performance approximation. The workflow is applied to a single-family reference building in Berlin and Chicago using 2025 weather and hourly retail prices with...

Automating Chemical Reasoning in High‐Throughput Phase Identification With a Probabilistic, LLM‐Guided Framework

Tue, 13 Oct 2026 00:00:00 +0000

Autonomous laboratories increasingly enable materials synthesis at scale, but traditional high-throughput characterization workflows remain limited by the need for expert chemical intuition to distinguish plausible interpretations from formally good but chemically incorrect fits. We present an automated interpretation framework that combines probabilistic inference with automated chemical reasoning for phase identification from powder x-ray diffraction (PXRD). The framework evaluates multiple candidate interpretations using diffraction pattern-based metrics. It then refines these likelihoods using chemically-informed priors derived from composition balance and a large language model (LLM)-based plausibility estimate with human-readable justification and also produces a trustworthiness score. In a blinded multi-project benchmark, the framework's top-ranked interpretation was selected over the lowest- baseline in 93% of cases where evaluators expressed a clear preference (95% CI:...

Towards healthy buildings: developing harm-metric frameworks to support design and decision-making

Thu, 8 Oct 2026 00:00:00 +0000

Current Indoor Air Quality (IAQ) regulations rely on concentration thresholds for individual pollutants, which limits their ability to capture cumulative health impacts and hinders the development of performance-based ventilation standards. Building on prior work, including Annexe D of ASHRAE 62.2, this study introduces a harm-based framework that shifts the reference from indoor concentrations to a standardised emission rate scenario. The proposed Harm Metric aggregates multiple contaminant exposures into a single health outcome expressed in DALYs·(105 pers)−1·year−1, enabling an outcome-based evaluation of ventilation performance. Applied to a representative sample of the French dwelling stock, the metric shows a median total harm of 994 DALYs·(105 pers)−1·year−1. The main contributors are particulate matter, formaldehyde, nitrogen dioxide (NO2), and radon. A ventilation sensitivity analysis demonstrates the metric’s responsiveness, with total harm decreasing to around 800 DALYs·(105...

Research Priorities for Robust Climate Assessments in the United States

Wed, 7 Oct 2026 00:00:00 +0000

Abstract Scientific assessments play a critical role in synthesizing evidence to support evidence‐based decision‐making in many sectors and topics. For climate change, large‐scale assessments like the Intergovernmental Panel on Climate Change (IPCC) and the United States (U.S.) National Climate Assessment (NCA) reports help many different users—from national government to local governments, Indigenous Peoples and communities, the private sector, the social sector, and the scientific community itself—navigate the complex field of climate risks, impacts, and integrated solutions. While co‐creation with users is essential to developing actionable assessments, this paper lays the groundwork for future processes by identifying many advancing and emerging areas of relevant knowledge ready for assessment or additional near‐term research. Drawing on the expertise of many scholars who were formerly tasked with producing the Sixth NCA and authors of other national or sub‐national climate...

Reverse polarization degradation of nickel iron oxyhydroxide anodes in alkaline water electrolysis

Fri, 2 Oct 2026 00:00:00 +0000

We report the effect of reverse polarization on thin-film Ni(Fe)OOH anodes in conditions that mirror those seen in commercial alkaline water electrolyzer stacks. Regardless of the extent of the reverse polarization potential, the anodic charge capacity decreases over successive cycles, indicating loss of active Ni2+/Ni3+ sites. Electrodes held for a longer period in the reduced state exhibited an accelerated catalyst loss through dissolution and structural reorganization during reverse polarization. In situ Raman spectroscopy and X-ray photoelectron spectroscopy revealed a significant decrease in the Fe:Ni surface ratio after reverse polarization, which correlates with a measurable decline in activity toward the oxygen evolution reaction. These findings illustrate how nickel iron oxyhydroxide anodes degrade during reverse polarization conditions and how managing the dissolved ions in the recirculating KOH improves anode lifetimes.

USB-C Outlets for Plug Loads in 350V DC Buildings

Thu, 1 Oct 2026 00:00:00 +0000

USB-C has become the universal plug standard for charging consumer electronics, typically through AC/DC wall adapters. As new standards in USB power distribution allow USB-C ports to provide up to 240W at 48V, many discuss the possibility of USB-C emerging as a plug-load standard, especially in DC buildings. This work proposes the use of USB-C wall outlets to power the emerging USB-C ecosystem without need for a wall adapter. We first study the market feasibility of USB-C outlets through a series of customer discovery interviews. We then perform several experiments to evaluate the technical feasibility. These include a comparative evaluation of efficiency and a thermal experiment to study how the heat from outlet's conversion loss can be dissipated through an exterior wall section.

Comparison of fast daylighting climate-based simulation methods for parametric design: two-phase, three-phase method and path tracing

Thu, 1 Oct 2026 00:00:00 +0000

Computer modeling and simulation are essential for predicting architectural solutions performance. When integrated into the design process; they are known as performance-based design. During the design process, fast analytical cycles are required. However, daylighting simulations are challenging due to computational processing and time requirements. This paper presents a comparative study of fast daylight simulation methods, two-phase, three-phase and path tracing, in a hypothetical commercial building located in Miami, Florida. Five types of static glass and one electrochromic glass were tested with six parametric models of a translucent horizontal shading device. Daysim was used as reference. The two-phase method produced results similar to the reference results with faster processing times for static facades. For dynamic facades, the path tracing method with the tested interface enabled faster simulations and parametric variations. However, the three-phase method yielded a...

Symmetry and Historicity in the Game of Life: Modifying Rules to Simulate Evolutionary Dynamics

Thu, 1 Oct 2026 00:00:00 +0000

The Game of Life (GoL) is a paradigmatic computer simulation that exhibits the emergence of complex properties of the whole from relatively simple sets of heuristic rules operating at lower organizational levels. Therefore, it is widely understood as a valuable tool for investigating global properties of evolutionary processes. Cognizant of refined concepts that emerged in recent debates on the central role of historical contingency (historicity) in evolution, we modify the original GoL rules by introducing an updating feedback loop and a probability factor that reflect the degree of historicity in pattern evolution as both stochastic path dependence and sensitivity to initial conditions. We examine this trait in simulations of the emergence and breaking of bilateral and radial symmetries commonly observed in the evolution of life, most prominently as evolving body plans. We show that the implementation of historicity parameters leads to a more realistic sequential and gradual...

Field Validation of Electrochemical Water Filtration System on an Open Loop Cooling Tower at Nissan Manufacturing Plant in Canton, Mississippi

Thu, 1 Oct 2026 00:00:00 +0000

Project Background The Industrial Technology Validation (ITV) program aims to identify and demonstrate the performance of new, emerging, and underutilized technologies in the industrial sector to help inform decisions towards accelerating commercialization and deployment. One such ITV project is to demonstrate the performance of an electrochemical water treatment technology on a cooling tower at an automotive plant. Cooling towers are vital equipment for dissipating heat from industrial processes. However, they face challenges related to scaling, corrosion, and the growth of biological contaminants. Effective cooling tower water filtration and treatment is essential to reduce these contaminants, along with other total suspended solids (TSS) and total dissolved solids (TDS) in the system. Various treatment systems, such as sand-based filters, centrifugal separators, and disc filters, offer distinct advantages and limitations. ElectroCell Systems offers a skid-mounted, electrochemical...

CO2 Conversion to Butene via a Tandem Photovoltaic–Electrochemical/Photothermocatalytic Process: A Co-design Approach to Coupled Microenvironments

Thu, 1 Oct 2026 00:00:00 +0000

We developed a tandem, unassisted, solar-driven electrochemical and photothermocatalytic process for the single-pass conversion of CO2 to butene using only simulated solar irradiation as the energetic input. The two-step process involves electrochemical CO2 reduction (CO2R) to ethylene followed by ethylene dimerization to butene. We assessed two unassisted electrochemical setups to concentrate ethylene in the CO2R reactor, achieving concentrations up to 5.4 vol% with 1.8% average solar-to-ethylene conversion and 5.6% average CO2-to-ethylene single-pass conversion under 1-sun illumination. When the effluent electrochemical gas stream was passed through the photothermocatalytic ethylene oligomerization reactor, we generated 600 ppm of butene under 3-sun illumination. Through analysis of this process, we identified that the presence of H2, CO, and H2O leads to rapid deactivation of the Ni-based ethylene oligomerization catalyst.

Field Validation of Electrochemical Water Filtration System on an Open Loop Cooling Tower at Toyota Motor Manufacturing Plant in Blue Springs, Mississippi

Thu, 1 Oct 2026 00:00:00 +0000

The U.S. Department of Energy Industrial Efficiency and Decarbonization Office’s Industrial Technology Validation (ITV) program aims to identify and demonstrate the performance of new, emerging, and underutilized technologies in the industrial sector to help inform decisions towards accelerating commercialization and deployment. One such ITV project is to demonstrate the performance of an electrochemical water treatment technology on a cooling tower at an automotive plant. Cooling towers are vital equipment for dissipating heat from industrial processes. However, they face challenges related to scaling, corrosion, and the growth of biological contaminants. Effective cooling tower water filtration and treatment is essential to reduce these contaminants, along with other total suspended solids (TSS) and total dissolved solids (TDS) in the system. Various treatment systems, such as sand-based filters, centrifugal separators, and disc filters, offer distinct advantages and limitations....

Going Big on Small Buildings: Spotlight on efforts to improve controls for packaged rooftop HVAC units

Thu, 1 Oct 2026 00:00:00 +0000

Commercial buildings with a floor area under 50,000 square feet comprise 95% of commercial buildings in the United States, representing almost half of all commercial buildings’ energy use. These buildings are typically underserved in terms of energy efficiency programs and are far more likely to be located in rural and disadvantaged communities, when compared with larger commercial buildings. The past decade has seen significant growth in the array of smart, innovative control technology options available for small to medium buildings, but currently, only 13% of buildings under 50,000 square feet have a building automation system installed. With expected 10% - 20% savings from installing controls, this represents a technical potential of 39 million tons reduction in U.S. greenhouse gas emissions, while simultaneously improving energy affordability for small business owners in disadvantaged communities and improving occupant comfort. Improved controls also enable more advanced...

Zero Net Energy Retrofits for Small Commercial Offices: Zero Net Energy Package and Tubular Daylighting Device FLEXLAB Test Results Report

Thu, 1 Oct 2026 00:00:00 +0000

This report is a part of the California Energy Commission Electric Program Investment Charge program study “Zero Net Energy Retrofits for Small Commercial Offices”. The four-year research study launched in January 2017 and it involves lab testing, field demonstration, performance measurement and verification, and occupant engagement efforts to move an integrated set of emerging commercial retrofit technologies into wider adoption in order for small commercial offices to achieve zero net energy (ZNE) performance. This document provides the results of the FLEXLAB testing of a ZNE retrofit package applicable to both Southern and Northern California climates. The retrofit package consisted of modulating supply diffusers, LED lighting and daylight dimming, reduced plug load power and tubular daylighting devices (TDDs) for providing daylighting into core spaces. This document also provides the daylighting availability and lighting energy reduction potential specifically for the TDDs....

Net Change in Energy Use from Ridehail Services in Five California Regions

Thu, 1 Oct 2026 00:00:00 +0000

Previously, we estimated the net change in energy use from ridehail services in Austin Texas. This estimate was based, in part, on assumptions regarding the number of rides involving two pooled parties and the distance drivers commuted into their service area to begin their driving day. The recent release of a year’s worth of Uber ridehail rides provided to California agencies, as well as recent surveys of driver commute behavior and the previous mode replaced by ridehail services, have enabled more accurate estimates of the net change in energy use from ridehail services statewide and in five regional markets. We find that the net reduction in energy use from more-efficient vehicles and pooled rides does not offset the additional increase in commute and between-ride deadhead kilometers and replacing more efficient modes with ridehail services. The net result is a 96% increase in statewide energy use (ranging from a 75% to a 123% increase in each region).

A Power-Centric Digitally-Managed 48V Distribution Technology

Thu, 1 Oct 2026 00:00:00 +0000

Technologies such as USB and Ethernet can be used to power devices in buildings, but have burdens of cost and energy efficiency that make them unsuitable as a primary means of distributing power to most loads in buildings. This paper describes a proposed standard for 48V DC power distribution in buildings suitable for powering most loads in residential and commercial buildings. It includes both general data communication as well as communication for managing the distribution of power. The maximum power is targeted at 1000 W with options for low- and high-power circuits to minimize costs.11This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Building Technologies Office, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Building Technologies Office, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Validating and comparing energy estimation methods at water resource recovery facilities

Wed, 30 Sep 2026 00:00:00 +0000

Water resource recovery facilities play a crucial role in the water–energy nexus, consuming a substantial amount of energy in the United States. Growing treatment volumes and more stringent water quality standards are expected to increase the amount of energy needed to treat wastewater, but accurately estimating energy consumption and potential remains challenging due to variability in scale, treatment methods, and effluent standards. In this study, we used publicly available data to evaluate the accuracy of methods for estimating energy consumption, then quantified uncertainty based on key factors like flow rate, treatment level, and geographic location. To validate methods, we estimated energy consumption at the facility level, then compared estimates to self-reported data from utilities in major U.S. cities. We found that methods based on effluent treatment level and flow rate performed well for estimating electricity consumption, and process models of treatment trains were...

Degradation Mechanisms of Fluorinated Disordered Rocksalt Cathodes: Effects of Electrolyte Chemistry and Discharge Voltage

Fri, 25 Sep 2026 00:00:00 +0000

Cation-disordered rock-salt (DRX) oxides have emerged as a promising class of high energy density cathodes for next-generation lithium-ion batteries. Fluorination has been widely employed to tune the redox chemistry and structural stability of these materials, leading to enhanced electrochemical performance. However, the degradation mechanisms of fluorinated DRX (F-DRX) cathodes during electrochemical cycling remain poorly understood. Here, we investigate the degradation behavior of an F-DRX cathode cycled in a conventional carbonate-based electrolyte and a localized high-concentration electrolyte (LHCE). By correlating electrochemical performance with interfacial and bulk structural evolution, we elucidate the role of electrolyte chemistry and deep discharge voltage in governing structural transformation and degradation. The results reveal more pronounced surface and bulk structural changes in the conventional LiPF6-carbonate electrolyte relative to LiFSI-LHCE, indicating accelerated...

Improving Evaluation and Adoption of Cool Exterior Walls for Heat Resilience

Wed, 23 Sep 2026 00:00:00 +0000

Extreme heat is a critical challenge that negatively impacts human health, energy use, air quality, social equity, and economic prosperity. In a world that continues to grow hotter by the year, cities in particular are suffering from an increase in heat waves and heat-related deaths. Buildings can play an integral role in urban heat island (UHI) mitigation through the use of solar-reflective “cool” surface materials. While cool roofs are one commonly used solution, research has demonstrated that cool exterior walls are also effective at mitigating UHIs and reducing cooling loads. As rising temperatures drive the need for more heat-resilient buildings, building energy codes, standards, and voluntary programs are adopting cool exterior wall provisions. ASTM C1549-16(2022), Standard Test Method for Determination of Solar Reflectance near Ambient Temperature Using a Portable Solar Reflectometer, is the primary standard used to measure the solar reflectance (SR) of building materials,...

Dynamic Metal-Semiconductor Electrical Interfaces in Model Cu|ZnO Hydrogenation Catalyst Structures

Mon, 21 Sep 2026 00:00:00 +0000

Cu/ZnO/Al 2 O 3 catalysts are commonly used for methanol synthesis, yet the chemical state of the Cu|ZnO interface remains debated. We probe Cu|ZnO interfacial chemistry by measuring junction electrical characteristics under N 2 , CO 2 and gas mixtures from 50 to 250 °C and up to 10 bar(a). The pristine interface behaves as a nonideal rectifying Schottky diode, and H 2 exposure drives a reversible transition toward ohmic behavior, with increased apparent n-type donor density in the ZnO and lower Schottky-barrier height. This result implies the electric potential at the putative active-catalyst interface decreases under reactive conditions. Recovery of rectifying behavior under O 2 and H 2 -free N 2 or CO 2 argues against persistent Cu–Zn alloying or oxygen-vacancy formation and supports reversible hydrogen doping of ZnO. CO 2 slows H insertion into ZnO relative to N 2 , while water strongly suppresses it. Junction electrical measurements thus inform how such catalytic interfaces...

Commercial, industrial, and institutional discount rate estimation for efficiency standards analysis Sector-level data 1998–2025

Mon, 21 Sep 2026 00:00:00 +0000

Underlying each of the U.S. Department of Energy’s (DOE’s) federal appliance and equipment energy conservation standards are a set of complex analyses of the projected costs and benefits of regulation. Any new or amended standard must be designed to achieve significant additional energy conservation, provided that it is technologically feasible and economically justified (42 U.S.C. 6295(o)(2)(A)). DOE determines economic justification based on whether the benefits exceed the burdens, considering a variety of factors, including the economic impact of the standard on consumers of the product and the savings in lifetime operating cost compared to any increase in price or maintenance expenses (42 U.S.C. 6295(o)(2)(B)).

As part of this determination, DOE conducts a life-cycle cost (LCC) analysis, which models the combined impact of appliance first cost and operating cost changes on a representative commercial building sample to identify the fraction of customers achieving...

Hydrogen Electrocatalysis on Perfluorosulfonic-Acid-Coated Pt

Fri, 18 Sep 2026 00:00:00 +0000

Membrane-electrode assemblies utilize ionomer-coated electrocatalysts to achieve facile ion transport. Consequently, isolation of intrinsic catalyst kinetics from measured polarization curves is challenging, as the properties of the catalyst and ionomer both affect the measurements. Here, we employ a Pt microelectrode coated by a thin perfluorosulfonic acid (PFSA) layer to measure polarization curves for the hydrogen oxidation reaction/hydrogen evolution reaction (HER/HOR). Intrinsic electrode kinetics are isolated by theoretical analysis of the local catalyst microenvironment, accounting for mass transport and thermodynamics. The observed enhancements in HER and HOR rates with increasing relative humidity (RH) at the working electrode are attributable to two competing factors: the decrease in activity of H+ in the ionomer and the dominant decrease in the water reorganization energy in the Marcus–Hush–Chidsey representation of HER/HOR kinetics. The increase in intrinsic rate with...

On the scaling of air entrainment from a ventilated partial cavity

Fri, 18 Sep 2026 00:00:00 +0000

Abstract The behaviour of a nominally two-dimensional ventilated partial cavity was examined over a wide range of size scales and flow speeds to determine the influence of Froude, Reynolds, and Weber number on the cavity shape, dynamics, and gas entrainment rate. Two geometrically similar experiments were conducted with a 14:1 length scale ratio. The results were compared to a two-dimensional semi-analytical model of the cavity flow, and Froude scaling was found to be sufficient to match basic cavity shapes. However, the air flux required to maintain a stable cavity did not scale with Froude number alone, as the dynamics of the cavity closure changed with increasing Reynolds number. The required air flux differed over one order of magnitude between the lowest and highest Reynolds number flows. But, for sufficiently high Reynolds numbers, the rate of scaled entrainment appeared to approach Reynolds number independence. Modest changes in surface tension of the...

Characterization of Metal-Supported Solid Oxide Electrolysis Cells Using FIB-SEM-TEM Techniques

Wed, 16 Sep 2026 00:00:00 +0000

This talk will present advanced characterization methods for pretest and posttest metal-supported solid oxide electrolysis cells (MS-SOEC). A unique symmetric cell architecture design, developed at Lawrence Berkeley National Laboratory (LBNL), has thin zirconia ceramic backbones and electrolyte sandwiched between porous metal supports, offers strong mechanical ruggedness, extremely fast start-up capability, and excellent tolerance to redox and dynamic operation for hydrogen production. Like conventional SOECs, MS-SOECs face component degradation that shorten lifetimes, making it critical to understand and mitigate component degradation and cell failure utilizing advanced characterization techniques. The metal support at the air side introduces chromium migration. A thin protective layer (CuMn1.8Ox) has been deposited on the metal support by electrophoretic deposition (EPD) to mitigate chromium evaporation and diffusion. Prior to EPD, the precursor particle size (5-10 μm) was reduced...

Influence of gas flow on elemental analysis using a tandem femtosecond LIBS and LA-ICPMS system

Wed, 16 Sep 2026 00:00:00 +0000

Gas flow of He–Ar mixtures affects the signals of a tandem LIBS and LA-ICPMS system. The integration of LIBS and LA-ICPMS allows for simultaneous determination of a wide range of elements and isotopes. Achieving high-precision quantitative analysis in this dual-technique approach requires establishing the optimal gas environment in the sample chamber. This study evaluated the impact of gas flow on a tandem femtosecond LIBS and LA-ICPMS system. By premixing helium and argon at various ratios, we created gas mixtures with gradient properties. NIST SRM 610 was used as the standard sample to assess the signal intensity and stability of optical emission spectroscopy and mass spectrometry. Our results showed that the LIBS intensity of Li( I ) 610.35 nm, Li( I ) 670.77 nm and Ca( I ) 644.90 nm, along with their relative standard deviation, increased with the proportion of argon in the gas mixture. Conversely, the LA-ICPMS intensity and relative standard deviation of each element decreased...

Constructing a Virtual Furnace for Solid-State Thermodynamic Models

Wed, 16 Sep 2026 00:00:00 +0000

Connecting 0 K density functional theory (DFT) energies to finite-temperature, finite-pressure synthesis conditions is a well-established thermodynamic formalism, yet quantified guidance on when and how to accurately calibrate these results to experimental chemical potentials in practice remains sparse. In this work, we systematically benchmark a complete workflowthe virtual furnacethat constructs effective oxygen chemical potentials (μO2) for common synthesis atmospheres (air, Ar, H2, CO) as functions of temperature and partial pressure and propagates quantified errors from formation enthalpies through reaction energies to critical chemical potentials. Applying this workflow to 11 binary oxides, we find that “gas-only” thermal corrections are sufficient at low temperatures and for Group II oxides across all temperatures, while solid-phase vibrational contributions become critical at elevated temperatures for transition metal oxides. We quantify this threshold through the ratio...

Dynamic Operation Strategies for High-Temperature Solid Oxide Electrolysis Cells

Wed, 16 Sep 2026 00:00:00 +0000

Solid oxide electrolysis cells (SOECs) are increasingly expected to operate under non-steady conditions rather than fixed steady-state loads. To enable future large-scale deployment, it is essential to understand how different forms of dynamic operation impact cell reliability. In this work, we establish a systematic evaluation framework to examine the durability of anode-supported SOECs under four representative dynamic stress modes: steam cycling (3–75% H₂O in H₂), reversible operation cycling between SOEC and SOFC modes, thermal cycling at both OCV (150–750 °C) and under load (600–800 °C at 1.3 V), and full vs. partial redox cycling (50% H₂ ↔ 50% N₂). Results indicate that steam cycling, mode switching, and thermal cycling at OCV do notinduce noticeable accelerated degradation, while thermal cycling under load remains largely tolerable within the tested temperature window. In contrast, full redox cycling leads to structural failure, whereas partial redox cycling produces manageable...

Quantitative analysis of fluorine and chlorine in apatite by femtosecond laser induced breakdown spectroscopy

Wed, 16 Sep 2026 00:00:00 +0000

fsLIBS setup and molecular emisson (CaF and CaCl) used in this study. Halogens, including fluorine (F) and chlorine (Cl), play essential roles in magmatic, hydrothermal, and ore-forming processes. Determining their geochemical behaviors is challenging due to their low abundance and volatility. Apatite containing halogens serves as an ideal recorder of Earth's and planetary processes. This study presents a quantitative method using molecular emission spectra of calcium fluoride (CaF) and calcium chloride (CaCl) to measure F and Cl concentrations in apatite through femtosecond laser-induced breakdown spectroscopy (fs-LIBS). Reference materials with varying F and Cl levels were employed to optimize conditions and develop calibration curves for F (0.55–3.75 wt%) and Cl (0.45–4.26 wt%), with detection limits of 0.22 wt% and 0.38 wt%, respectively. The calibration curves achieved R 2 values of 0.995 for F and 0.992 for Cl, with RMSRE of 8% for F and 13% for Cl. Validation using natural...

Simulation driven design approach and prototype development for low-cost high-efficiency room air conditioners using next generation refrigerants

Wed, 16 Sep 2026 00:00:00 +0000

The global refrigerant transition requires the redesign of heating, ventilation and air-conditioning (HVAC) systems. Higher efficiency systems also reduce peak loads and allow better integration of secure, affordable, reliable base-load generation technologies. However, many small and medium-sized air conditioner (AC) manufacturers, particularly in developing and emerging economies, lack the technical capacity to design affordable, energy-efficient systems using next generation refrigerants. This study presents a simulation-driven design approach for developing cost-effective, high-efficiency mini-split AC prototypes using R32, R454B, and R290. Physics-based system models were developed in VapCyc® and CoilDesigner® to conduct component-level simulations and system optimization. Cost analysis was performed to minimize material costs, and optimal designs were validated under ISO 5151 conditions in a psychrometric chamber. All prototypes achieved 33% higher EER and nearly doubled...

Biosynthesis of polycyclopropanated high energy biofuels

Tue, 15 Sep 2026 00:00:00 +0000

Cyclopropane-functionalized hydrocarbons are excellent fuels due their high energy density. However, the organic synthesis of these molecules is challenging. In this work, we produced polycyclopropanated fatty acids in bacteria. These molecules can be converted into renewable fuels for energy-demanding applications such as shipping, long-haul transport, aviation, and rocketry. We explored the chemical diversity encoded in thousands of bacterial genomes to identify and repurpose naturally occurring cyclopropanated molecules. We identified a set of candidate iterative polyketide synthases (iPKSs) predicted to produce polycyclopropanated fatty acids (POP-FAs), expressed them in Streptomyces coelicolor, and produced POP-FAs. We determined the structure of the molecules and increased their production 22-fold. Finally, we produced polycyclopropanated fatty acid methyl esters (POP-FAMEs). Our POP fuel candidates can have net heating values of more than 50 MJ/L. Our research shows...

Travel and energy implications of ridesourcing service in Austin, Texas

Tue, 15 Sep 2026 00:00:00 +0000

This paper identifies major aspects of ridesourcing services provided by Transportation Network Companies (TNCs) which influence vehicles miles traveled (VMT) and energy use. Using detailed data on approximately 1.5 million individual rides provided by RideAustin in Austin Texas, we quantify the additional miles TNC drivers travel: before beginning and after ending their shifts, to reach a passenger once a ride has been requested, and between consecutive rides (all of which is referred to as deadheading); and the relative fuel efficiency of the vehicles that RideAustin drivers use compared to the average vehicle registered in Austin. We conservatively estimate that TNC drivers commute to and from their service areas accounts for 19% of the total ridesourcing VMT. In addition, we estimate that TNC drivers drove 55% more miles between ride requests within 60 min of each other, accounting for 26% of total ridesourcing VMT. Vehicles used for ridesourcing are on average two miles per...

Recent developments in primary copper supply in the United States

Tue, 15 Sep 2026 00:00:00 +0000

Demand for copper is expected to increase in the United States as energy infrastructure expands to accommodate data centers, new electricity generation, and electric vehicles. While scaling-up recycling of copper is important for meeting domestic demand, a number of active and emerging copper producers have announced new activities for expanding primary copper production. Generalized market and facility-level models representing mine energy and materials flows have been developed, but the potential future portfolio of mining supply is diverse and requires further characterization to support planning for supply chains and technology deployment. Herein, we present a dataset of mine projects, providing estimates of copper productivity by technology pathway. We review diesel, electricity, water, and tailing waste generation factors reported in literature and used in life-cycle assessment databases, highlighting inconsistencies and gaps where values do not represent primary production...

Integrated Whole-Building Zero Net Energy Retrofits for Small Commercial Offices

Tue, 15 Sep 2026 00:00:00 +0000

Small commercial offices experience a number of unique barriers to achieving substantial energy reductions including: 1) a lack of awareness of and access to costevaluative information about how to achieve energy targets, and 2) affordable access to services such as engineering and audits. Existing tools and services currently involve higher costs when applied to small commercial buildings due to the lower amount of energy cost savings realizable on a per-square-foot basis. Small commercial buildings are consequently disadvantaged in accessing the same detailed retrofit information that larger buildings can gain cost effectively. This project developed cost-effective retrofit packages to achieve zero net energy and/or zero carbon performance for California multi-story small commercial offices (<50,000 sf). The packages target 50 percent energy savings, with costs within 10 percent of conventional construction costs, and internal rates of return of 5 percent or more within...

Imported biomass for power generation under domestic resource constraints: trade-offs between cost, supply feasibility, and emissions in Japan

Tue, 15 Sep 2026 00:00:00 +0000

Many countries face structural constraints that limit large-scale deployment of solar and wind power, necessitating the import of alternative fuels to reduce emissions. Using a high-resolution capacity expansion and dispatch model (SWITCH-Japan), we assess the role of imported biomass under varying policy constraints and fuel price assumptions. Results indicate that imported biomass is not utilized when renewable deployment is unconstrained. However, under constrained scenarios, biomass imports rise substantially, reaching up to 15% of electricity supply by 2050 and increasing system costs by up to 32% relative to least-cost pathways. This corresponds to biomass demand exceeding 140 Mt yr−1—far above current global trade levels—highlighting potentially severe supply constraints. While biomass provides firm capacity, it raises important environmental concerns, including life-cycle emissions, land-use impacts, and carbon debt, and competes directly with hydrogen and nuclear power...

DAYLIGHTING AND ELECTRIC LIGHTING: SYSTEMS INTEGRATION

Mon, 14 Sep 2026 00:00:00 +0000

This scoping study sets the stage for transforming the design and implementation of integrated lighting systems (daylight and electric), and thereby helping to achieve long-term objectives in energy savings goals established by the U.S. Department of Energy’s (DOE) Building Technologies Office (BTO). While integrated lighting systems may reduce building energy use, a broader network of non-energy benefits affecting overall health, comfort, and satisfaction of building occupants may also influence technology investment objectives when considering the entire lifecycle of the built environment. Lighting systems in today’s typical buildings are disconnected from other systems and their control mechanisms. Being disassociated from the inputs and outputs of those systems, and unable to capture and capitalize on the information those systems gather, prevents realizing the dynamic nature of holistic human responses to light inside buildings. In the future, lighting in new and existing...

This article is a summary of CLTC research aimed at developing a technology-neutral Super Lamp specification for replacement of incandescent sources in the residential sector

Mon, 14 Sep 2026 00:00:00 +0000

The research has been performed at the California Lighting Technology Center (CLTC) in order to achieve required energy performance and develop a technology-neutral Super Lamp specification for replacement of incandescent technologies in the residential sector. The CLTC specification considered several factors that included color, size, run-up time, and frequent lamp failure in enclosed luminaries or downlights. The Super Lamp specification focuses only on lamps with a nominal correlated color temperature (CCT) of 2,700 K. The minimum values were specified for special color rendering indices that were determined by estimating, based on efficacy and CRI measurements of 2,700 K CFLs of varying CRI. The Super Lamp requirement for run-up time, 45 seconds, was based on the fastest run-up characteristic observed in the CLTC laboratory with commercially-available amalgam lamps. The California utilities are in the process of determining their incentive structure for high-efficacy screw-base...

Research matters

Mon, 14 Sep 2026 00:00:00 +0000

Extensive researchers efforts have played a key role in enabling high dynamic range (HDR) imaging to be used in several consumer electronics products. Some of these consumer electronics include cameras, mobile phones, and the latest version of the iPhone. The HDR technology has been integrated in these devices to provide better lighting experience. HDR imaging has been used for research purposes for a long period of time and has become practice in many of the devices as new digital cameras and specialized software have been developed to speed and facilitate processes. HDR imaging involves a series of photographs of a luminous scene from the same viewpoint, ranging from fully underexposed to fully over-exposed images that are processed by software to produce luminance maps. There are several systems to produce luminance maps using HDR photography, including the Photolux system using the Nikon Coolpix 5400 camera and a fisheye lens.

Circadian lighting in a space daylit by a tubular daylight device

Mon, 14 Sep 2026 00:00:00 +0000

This study demonstrates an experimental example of application of time-lapse high dynamic range images for analyzing variations in correlated color temperature (CCT) and circadian lighting in an interior space daylit using a tubular daylight device (TDD). Previous studies have shown that the spectral composition of daylight affects human circadian rhythms, with emphasis on wavelengths towards the blue region of the visible spectrum. Spectrally based metrics such as CCT can therefore aid in evaluating the circadian impact of daylight. TDDs redirect daylight towards interior spaces with changing light levels and color temperatures during the daylight hours. This paper details the color temperature and circadian lighting metrics (circadian luminance and illuminance) in an interior space throughout a period of several days in a mid-latitude, temperate, sunny climate. An automated time-lapse HDR photography apparatus was modified to allow for calculation of CCT and circadian lighting...

Laboratory testing of a high efficiency light redirection system

Mon, 14 Sep 2026 00:00:00 +0000

Automated daylight redirecting slat technologies are designed to divert sunlight into the living space. They have a distinct advantage in that they can be retracted and extended, and slat angles can be adjusted according to the solar geometry and sky conditions. This study aimed to explore the geometric and photometric properties of a novel high-efficiency light redirection system (LRS). The LRS prototypes were installed in the clerestory window in the south-facing window testbed office and monitored under real sun and sky conditions. Workplane illuminance, daylight delivery efficiency (DDE) and visual comfort were evaluated. A number of simulation studies were conducted to evaluate the LRS and compare the results to the laboratory tests. The study shows that the specular properties of the slats provided significantly higher work plane illuminance and DDE. All systems showed an acceptable discomfort glare, or daylight glare probability (DGP) lower than 0.35. The comparison of...

Least-cost Optimal Distribution Grid Expansion (LODGE): Utility Pilots

Mon, 14 Sep 2026 00:00:00 +0000

The Least-cost Optimal Distribution Grid Expansion (LODGE) model provides the optimal portfolio of distribution system upgrades—e.g., voltage regulators, feeder reconductoring, transformer upgrades and non-wires alternatives (NWA), such as strategic siting of storage and distributed generation—to interconnect distributed energy resources (DERs) and enable load growth. It can be used to assess grid infrastructure costs and explore policy and regulatory solutions for distribution planning and DER valuation.

In 2025, Berkeley Lab conducted three pilot analyses to validate LODGE results with empirical utility data before the model’s first release in 2026. The pilots, done with utilities in Washington, Colorado, and New Mexico, provide examples that illustrate how the model works, what it can do, and the value of the analysis.

Author Correction: US oil and gas system emissions from nearly one million aerial site measurements

Fri, 11 Sep 2026 00:00:00 +0000

Correction to: Naturehttps://doi.org/10.1038/s41586-024-07117-5 Published online 13 March 2024 In the version of the article initially published, several errors were present and have been corrected in the HTML and PDF versions of the article and Supplementary Information. The main results, conclusions, and our interpretations of the data remain unchanged. See the new Supplementary Information Section S15 for a more detailed description of the errors corrected and the resulting effects on the analysis. Data processing and methods corrections Overflight count correction: We previously used pre-computed source coverage data for some Carbon Mapper campaigns that was computed differently than was required for our analysis. We have re-computed Carbon Mapper source coverage based on flightline polygons and source coordinates. Transition point computation, well sites: The updated version now correctly compares the cumulative emissions distribution of simulated well site emissions with...

A review of United States energy-only generator interconnection service policy and considerations for reform

Fri, 11 Sep 2026 00:00:00 +0000

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...

U.S. ESCO Industry Report: Industry Size and Recent Market Trends, 2022- 2024

Fri, 11 Sep 2026 00:00:00 +0000

The latest edition of the U.S. Energy Service Company (ESCO) Industry Report by Lawrence Berkeley National Laboratory (LBNL) finds that the U.S. ESCO industry continues to show strong growth. The report draws from ESCO industry reported revenue data for the 2022-2024 period, detailing the current size and characteristics of the U.S. ESCO industry. Following 20 years of ESCO industry reports, the 2024 report explores significant revenue trends across market segments, geographic regions, ESCO size, financing structures, and business activities. New analysis in this report outlines customer priorities and non-energy benefit drivers of Energy Savings Performance Contract projects, adjusted revenue analysis detailing the impacts of inflation on industry growth, and project challenges by market segment.

Evaluating technology upgrades as a complement to traditional bill assistance programs

Thu, 10 Sep 2026 00:00:00 +0000

State programs to improve energy affordability and reduce energy burden (the share of income spent on energy) could mitigate concerns about rising electricity prices. Many states offer bill assistance and rebates for weatherization and rooftop solar to income-qualifying households. Here, we analyse how these approaches may complement one another to improve energy affordability. Results illustrate trade offs between program costs and energy burden reduction, as well as between a program’s upfront and ongoing costs. Generally, the three strategies complement one another to improve energy affordability at lower net present cost than bill assistance alone, with varying effects across regions. Weatherization can reduce the solar installation capacity needed, and both together can reduce or eliminate ongoing reliance on bill assistance. Under full uptake among cost-effective households, fully rebated weatherization and solar rebated at $0.48/Watt, combined with bill assistance, yield...

A Signal‐Derived Retrieval Reduces Bias in TEMPO NO2

Wed, 9 Sep 2026 00:00:00 +0000

Abstract Satellite measurements of are widely used for investigations of emissions, pollution exposure, and photochemical ozone production. The most commonly available data products compromise on accuracy and spatial resolution in favor of lower compute time. In addition to limited spatial resolution, inaccurate modeling of winds and misrepresentation of the lifetime contribute to large systematic errors in the satellite retrievals that depend on these modeled outputs. We introduce a signal‐derived retrieval (SDR) for Tropospheric Emissions: Monitoring of Pollution (TEMPO) which derives instrument‐resolution a priori profiles from measured slant column densities. This approach enables fast reprocessing of TEMPO data and removes the gradient smoothing caused by low resolution priors and systematic errors in models. The SDR product reduces the negative bias of TEMPO total against Pandora reference measurements by , with a larger impact on the tropospheric column. This bias correction...

Ten questions on digital twins of buildings for transforming building operations

Wed, 9 Sep 2026 00:00:00 +0000

Buildings are becoming ever more complex to manage during operations, driven by increasing dynamics in energy demand, intermittent on-site power generation, and distributed energy resources, compounded by variable grid pricing signals and the rising threat of extreme weather events causing large-scale power outages. To achieve optimal performance in energy efficiency, demand flexibility, energy resilience, and occupant comfort, new methods and tools are essential for transforming design and operations across a building’s entire life cycle. Digital Twins (DTs), enabled by recent advances in ubiquitous sensing, big data, cloud computing, and AI, offer a transformative approach to creating a real-time, bi-directional digital counterpart of a physical building. This paper presents ten critical questions highlighting the most foundational issues underpinning the successful deployment of digital twins for buildings. The questions are holistically structured around three core themes...

Interconnection Timelines and Costs for Distributed Energy Projects in the United States (2000-2025)

Fri, 4 Sep 2026 00:00:00 +0000

These slides summarize and explain empirical data on interconnection timelines and costs for distributed energy projects connected to U.S. utility distribution systems. The study explores how interconnection metrics vary across states, project sizes, technology types, and over time to indicate progress toward simple, fast, and affordable interconnection. Data encompasses 188 utilities in 24 states. Project types include biomass/biofuels, coal, hydropower, natural gas/oil, solar, storage, wind, hybrid, and

Technical assessment of the negative solar radiative forcing and atmospheric cooling benefits of surface brightening projects

Thu, 3 Sep 2026 00:00:00 +0000

Brightening the Earth’s surface can increase the outflux of sunlight to space. This diminishes the net (downward minus upward) solar flux into the Earth’s radiative system, providing negative solar radiative forcing that can cool the atmosphere. We are quantifying the extent to which surface-brightening projects, such as installing solar-reflective roofs and pavements, can raise bottom-of-atmosphere (BOA) albedo, increase top-of-atmosphere (TOA) solar outflux, and reduce regional and global atmospheric temperatures. We compared four approaches to assessing BOA albedo: roof- or pavement-product documentation; local measurements with an albedometer (back-to-back pyranometers); extrapolation from extended-color aerial images (blue, green, red, and near-infrared); and multispectral satellite images sharpened by convolution with aerial images, selecting the last. We developed a technique to calculate the atmosphere’s upward solar transmittance anywhere in the Earth’s tropical and temperate...

Towards robust laser beam propagation in atmospheric turbulence

Tue, 1 Sep 2026 00:00:00 +0000

High-fidelity optical propagation through the atmosphere is essential for free-space optical technologies, including laser-based remote sensing and optical communication. However, atmospheric turbulence severely distorts beams and compromises system performance. In this work, we employ hypergeometric-Gaussian (HyGG) vortex beams as probes to characterize and mitigate atmospheric turbulence. Using over 250,000 experimental and simulated frames, we show that refining the power spectrum density (PSD) can reduce numerical prediction errors by up to 79.8%. Concurrently, experimental observations supported by numerical simulations demonstrate that HyGG beams exhibit superior turbulence resilience across multiple metrics compared to conventional Gaussian beams, particularly in their ability to withstand over 5 times stronger turbulence while maintaining similar intensity fluctuations. These dual investigations, on both turbulence mitigation and robust beam solutions, converge to form...

Selecting Critical Scenarios of DER Adoption in Distribution Grids Using Bayesian Optimization

Tue, 1 Sep 2026 00:00:00 +0000

We develop a new methodology to select scenarios of DER adoption most critical for distribution grids. Anticipating risks of future voltage and line flow violations due to additional PV adopters is central for utility investment planning but continues to rely on deterministic or ad hoc scenario selection. We propose a highly efficient search framework based on multi-objective Bayesian Optimization. We treat underlying grid stress metrics as computationally expensive black-box functions, approximated via Gaussian Process surrogates and design an acquisition function based on probability of scenarios being Pareto-critical across a collection of line- and bus-based violation objectives. Our approach provides a statistical guarantee and offers an order of magnitude speed-up relative to a conservative exhaustive search. Case studies on realistic feeders with 200-400 buses demonstrate the effectiveness and accuracy of our approach.

Simple device modification simultaneously enhances indoor passive evaporative cooling power and duration

Tue, 1 Sep 2026 00:00:00 +0000

Passive evaporative cooling from a damp cloth or vessel can be used for localized cooling of perishables such as food and medicine, drinking water, and even people. Such applications have two key objectives, which are normally in tension with each other: minimizing the water consumption rate and maximizing the cooling (steady-state temperature swing between the cool cloth and the warm surroundings). Here, we present a simple device that delivers higher performance in both metrics simultaneously by adding a perforated aluminum foil sheet suspended over a stagnant air layer to thermally shield the evaporating surface while also facilitating mass transfer. Experimental results demonstrate a simultaneous 10%–25% increase in temperature swing and 2–3× reduction in water consumption rate as compared to conventional evaporative cooling. This improvement is achieved through careful modeling to optimize the coupled heat and mass transfer through the airgap (thermally insulating and vapor...

Market participation strategy of hybrid energy resources: A New York ISO case study

Tue, 1 Sep 2026 00:00:00 +0000

Drawing on existing market designs with independent resource participation in electricity markets, this study analyzes participation models for hybrid resources combining renewable generation and storage. Two models are considered: in the first, the components operate independently, with the Independent System Operator (ISO) managing the storage state of charge (SoC); in the second, the hybrid resource acts as an integrated unit, submitting offers as a “black box” and managing its SoC internally. Using a production cost model for the zonal New York Bulk Power System, we evaluate trade-offs in system reliability, market efficiency, and asset profitability. Our results provide several key insights for policymakers, showing that the ISO-managed granular model enhances social welfare through explicit SoC management, while the simpler integrated model is more computationally efficient, but may cause more real-time violations and lower overall profits.

Ultrafast Nanoimaging of Carrier Funneling in Composition-Graded Semiconductor Nanowires

Tue, 1 Sep 2026 00:00:00 +0000

Recent advances in bandgap engineering of low-dimensional semiconductors have enabled high-efficiency carrier transport in miniaturized electronic and optoelectronic devices. The physical properties and functionalities of these materials are governed by complex carrier dynamics coupled with multiple transport mechanisms in tailored band structures. Here, we report ultrafast nanoimaging of carrier funneling and recombination in composition-grade CdS_xSe_1-x nanowires using pump-probe near-field nanoscopy. Leveraging the high resolution of this technique in both space and time, we resolve nanoscale local carrier dynamics along composition-graded nanowires, revealing the local variation of composition-dependent carrier mobilities and lifetimes that significantly differ from their uniform composition counterparts. Furthermore, we demonstrate a length-dependent behavior wherein shorter nanowires exhibit enhanced funneling effects, accelerating carrier...

Joint scheduling of energy, fast and primary frequency response reserves in integrated transmission–distribution networks

Tue, 1 Sep 2026 00:00:00 +0000

Inverter-based distributed energy resources (DERs) connected to distribution networks (DNs) can provide fast frequency support, but their reserve deliverability depends on feeder constraints and differs from synchronous primary frequency response (PFR). Existing transmission–distribution coordination studies usually treat reserve generically or neglect feeder-level feasibility, while frequency-security scheduling studies rarely represent distribution feeders explicitly. This paper develops a bi-level day-ahead scheduling framework for integrated transmission–distribution networks that jointly clears energy, transmission-side PFR, and distribution-side fast frequency response (FFR) under exogenous hourly inertia and largest-loss inputs from an external unit commitment (UC) schedule. The transmission problem is modeled with DC-optimal power flow (OPF) and closed-form second-order cone (SOC) frequency-security constraints, whereas each DN is represented by a reserve-aware branch-flow...

A model for selecting the best sustainable airport technology alternatives

Tue, 1 Sep 2026 00:00:00 +0000

Air transport is a continually expanding industry, a fact that has become even more evident with the recovery of the aviation industry post-COVID-19. This expansion amplified energy consumption at airports, which was already significantly high. Airport decision-makers are increasingly focusing on improving sustainability and addressing social, economic, and environmental criteria across airports worldwide. In this article, we propose a decision-making model for identifying a sustainable airport technology solution that minimizes the energy consumption of airport lighting while considering economic, emission, and life-cycle criteria. The proposed model combines data envelopment analysis and multi-criteria decision making techniques. We applied the model to the Dallas/Fort Worth International Airport (DFW) as a case study, considering eight lighting technology solutions, each with five luminous flux alternatives. Our model identified the best lighting technology solution for DFW...

Endogenous Interface Pricing for Consistent Transmission–Distribution Co-Optimization With Discrete Distribution Controls

Tue, 1 Sep 2026 00:00:00 +0000

This paper proposes an endogenous interface pricing model for day-ahead transmission–distribution co-optimization that co-determines the interface locational marginal price (LMP) and the transmission–distribution exchange, ensuring price–dispatch consistency while optimally scheduling discrete distribution controls. The formulation couples a DC optimal power flow (OPF) with a branch-flow AC OPF that schedules distributed energy resources (DERs), tap-changer settings, capacitor banks (CBs), and multi-period energy storage systems (ESSs) under feeder voltage and current limits, and is solved as a mixed-integer second-order cone program (MISOCP). In a T14–D33 system, coordinated device scheduling recovers about 90% of the distribution-to-transmission export achievable in a reference case that ignores distribution network (DN) limits, while satisfying a 1.05 p.u. voltage upper bound. In a T39–D34/D37/D123 system, a sequential decoupled benchmark produces interface LMP distortions...

Cataloging US state policy patterns towards microgrid deployment

Tue, 1 Sep 2026 00:00:00 +0000

Frequent extreme weather events have called for rigorous and timely efforts for alternative non-wire solutions. These efforts are getting more widespread to offer a perfect alternative as the conventional grid becomes progressively less resilient. One of these solutions is microgrids that can disconnect from the grid and offer grid resilience during an outage. While this technology is still finding its footing in the industry, states across the US are employing policy patterns and forms of instruments to support its deployment. This study includes a systemic review of the US by conducting a binary analysis of all 50 states (including Washington D.C, excluding other US territories) using seven variables. The results show four major policy approaches to microgrids: i) supporting microgrids through a definitive legislative activity leading to further policy action; ii) direct efforts from the public utilities commissions without a concrete legislative push; iii) initiatives from...

Burst delay line for generating ultrashort pulse bursts with interval tunability from femtoseconds to nanoseconds.

Tue, 1 Sep 2026 00:00:00 +0000

Ultrashort burst laser pulses are important for applications in laser processing and spectroscopy. However, existing burst generators face limitations in pulse time interval tunability and coaxiality. Here, we present a burst pulse generator that delivers coaxial ultrashort pulses with tunable pulse time intervals using a single translation stage. The constructed system produced eight femtosecond pulses with uniform intervals tunable from 100 fs to 1.93 ns, equivalent to burst-internal repetition rates spanning 10 THz to 0.52 GHz. We further demonstrated interval-dependent plasma emission in air filamentation, providing a compact platform to study burst-laser-induced phenomena.

Nanoscale Compositional and Strain Gradients Enable High‐Speed and Amplitude‐Resolved Pyroelectric Sensing

Tue, 1 Sep 2026 00:00:00 +0000

The frequency response of pyroelectric sensors is fundamentally governed by thermal time constant (τ_th, determined by thermal mass and thermal conductance) and electrical impedance arising from film capacitance and readout circuit. Conventional bulk LiTaO₃ detectors are optimized for high responsivity at low modulation frequencies (0.1-10 Hz), possessing a large τ_th that thermally averages rapid temperature oscillations at elevated modulation frequencies, limiting fidelity in resolving dynamic varying thermal signals. Here, compositional and strain gradients are introduced into 100-nm-thick relaxor-ferroelectric films reducing τ_th to ≈2 µs and producing built-in potentials (≈1.45 V or 145 kV cm^-1) that enhance the pyroelectric coefficient and suppress the dielectric constant. This enables complementary dual-mode operation by enhancing current-mode electrical responsivity and improving the voltage-mode figure...

Netload Range Cost Curves for Coordinated Transmission-Distribution Planning Under DER Growth Uncertainty

Tue, 1 Sep 2026 00:00:00 +0000

The increasing penetration of distributed energy resources (DERs) requires better coordination between transmission and distribution (T&D) planning to ensure system security and cost efficiency. However, misaligned planning horizons, computational burdens, and privacy concerns hinder effective coordination, leading to either underutilized resources caused by overinvestments or reliability risks due to underinvestment. To address this challenge, we introduce netload range cost curves (NRCCs), a novel approach for managing long-term DER growth uncertainty through T&D coordination, while preserving existing data-sharing and regulatory structures. NRCCs provide pairs of (i) peak substation netload guarantees and (ii) corresponding distribution upgrade options and costs, enabling their seamless integration into transmission planning workflows. To compute NRCCs efficiently, we develop a transmission-aware distribution network planning (TADNP), which is subsequently integrated...

Decision-Dependent Resilience Enhancement Strategy for Distribution Systems Against Endogenous Wildfires