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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Adaptive Management Methods to Protect the California Sacramento-San Joaquin Delta Water Resource

The California Sacramento-San Joaquin River Delta is the hub for California's water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

Agriculture↗
DOE OSTI2018

Assessing fossil fuel CO 2 emissions in California using atmospheric observations and models

Analysis systems incorporating atmospheric observations could provide a powerful tool for validating fossil fuel CO 2 (ffCO 2 ) emissions reported for individual regions, provided that fossil fuel sources can be separated from other CO 2 sources or sinks and atmospheric transport can be accurately accounted for. We quantified ffCO 2 by measuring radiocarbon ( 14 C) in CO 2 , an accurate fossil-carbon tracer, at nine observation sites in California for three months in 2014-15. There is strong agreement between the measurements and ffCO 2 simulated using a high-resolution atmospheric model and a spatiotemporally-resolved fossil fuel flux estimate. Inverse estimates of total in-state ffCO 2 emissions are consistent with the California Air Resources Board's reported ffCO 2 emissions, providing tentative validation of California's reported ffCO 2 emissions in 2014-15. Continuing this prototype analysis system could provide critical independent evaluation of reported ffCO 2 emissions and emissions reductions in California, and the system could be expanded to other, more data-poor regions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Evaluating cross-sectoral impacts of climate change and adaptations on the energy-water nexus: a framework and California case study

Abstract Electricity and water systems are inextricably linked through water demands for energy generation, and through energy demands for using, moving, and treating water and wastewater. Climate change may stress these interdependencies, together referred to as the energy-water nexus, by reducing water availability for hydropower generation and by increasing irrigation and electricity demand for groundwater pumping, among other feedbacks. Further, many climate adaptation measures to augment water supplies—such as water recycling and desalination—are energy-intensive. However, water and electricity system climate vulnerabilities and adaptations are often studied in isolation, without considering how multiple interactive risks may compound. This paper reviews the fragmented literature and develops a generalized framework for understanding these implications of climate change on the energy-water nexus. We apply this framework in a case study to quantify end-century direct climate impacts on California’s water and electricity resources and estimate the magnitude of the indirect cross-sectoral feedback of electricity demand from various water adaptation strategies. Our results show that increased space cooling demand and decreased hydropower generation are the most significant direct climate change impacts on California’s electricity sector by end-century. In California’s water sector, climate change impacts directly on surface water availability exceed demand changes, but have considerable uncertainty, both in direction and magnitude. Additionally, we find that the energy demands of water sector climate adaptations could significantly affect California’s future electricity system needs. If the worst-case water shortage occurs under climate change, water-conserving adaptation measures can provide large energy savings co-benefits, but other energy-intensive water adaptations may double the direct impacts of climate change on the state’s electricity resource requirement. These results highlight the value of coordinated adaptation planning between the energy and water sectors to achieve mutually beneficial solutions for climate resilience.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Calcium is associated with specific soil organic carbon decomposition products at Blodgett Forest Research Center, Georgetown, California as analysed with scanning transmission X-ray microscopy carbon near-edge X-ray absorption fine structure spectroscopy

This data is from the paper calcium is associated with specific soil organic carbon decomposition products, published in SOIL. DOI: https://doi.org/10.5194/soil-11-381-2025, 2025.This file contains CSVs with spectral data and bulk soil data and there is no specific program required to open this data. The data includes Scanning transmission X-ray microscopy carbon near-edge X-ray absorption fine structure spectroscopy. data from the measurement of samples from the Whole-soil Warming project, run by the Belowground Biogeochemistry team at Blodgett Forest Research Center, Georgetown, California run by the University of California, Berkeley. It also includes bulk soil chemical properties. The University of California's Blodgett Forest Research Station (Forest) is situated in the Sierra Nevada foothills (1370 m a.s.l.) near Georgetown, California. The samples were collected from here: 38.912013, -120.661469, https://maps.app.goo.gl/291bCJ1zVqUhgktz6. The Forest soils were characterised as Alfisols, which are equivalent to Dystric Cambisols (IUSS Working Group WRB, 2015), and formed in granitic parent materials, in a temperate climate, under thinned, mixed-coniferous forest (Fig. S3; Gaudinski et al., 2009). With these analyses we aimed to answer the question, is calcium associated with a specific type of organic matter enriched in aromatic and phenolic carbon at the microscale in samples from Blodgett Forest Research Center? and how does this specific type of carbon respond to experiments targetted at removing and adding calcium to the soils, specifically cation exchange and incubation after calcium addition? Abstract from the paper can be found below: Calcium (Ca) may contribute to the preservation of soil organic carbon (SOC) in more ecosystems than previously thought. Here we provide evidence that Ca is co-located with SOC compounds that are enriched in aromatic and phenolic groups, across different acidic soil-types and locations with different ecosystem properties, differing in terms of climate, parent material, soil type, and vegetation. In turn, this co-localised fraction of Ca-SOC is removed through cation-exchange, and the association is then only re-established during decomposition in the presence of Ca (Ca addition incubation). Thus, highlighting a causative link between decomposition and the co-location of Ca with a characteristic fraction of SOC. Decomposition increases the relative proportion of negatively charged functional groups, which can increase the propensity for the association between SOC and Ca, and in turn, this association inhibits dissolved organic carbon export or further decomposition. We propose that this mechanism could be driven by Ca hotspots on the microscale shifting local decomposition processes and thereby explaining the colocation of Ca with SOC of a specific composition across different acidic soil environments. Incorporating this biogeochemical process into Earth System Models could improve our understanding, predictions, and management of carbon dynamics in soils, and account for their response to Ca-rich amendments.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

California-Wyoming Grid Integration Study: Phase 1—Economic Analysis

This study presents a comparative analysis of two different renewable energy options for the California energy market between 2017 and 2020: 12,000 GWh per year from new California in-state renewable energy resources; and 12,000 GWh per year from Wyoming wind delivered to the California marketplace. Either option would add to the California resources already existing or under construction, theoretically providing the last measure of power needed to meet (or to slightly exceed) the state's 33% renewable portfolio standard. Both options have discretely measurable differences in transmission costs, capital costs (due to the enabling of different generation portfolios), capacity values, and production costs. The purpose of this study is to compare and contrast the two different options to provide additional insight for future planning.

17 WIND ENERGY↗
DOE OSTI2010

California Energy Balance Update and Decomposition Analysis for the Industry and Building Sectors (Final Report)

This report on the California Energy Balance version 2 (CALEB v2) database documents the latest update and improvements to CALEB version 1 (CALEB v1) and provides a complete picture of how energy is supplied and consumed in the State of California. The CALEB research team at Lawrence Berkeley National Laboratory (LBNL) performed the research and analysis described in this report. CALEB manages highly disaggregated data on energy supply, transformation, and end-use consumption for about 40 different energy commodities, from 1990 to 2008. This report describes in detail California's energy use from supply through end-use consumption as well as the data sources used. The report also analyzes trends in energy demand for the "Manufacturing" and "Building" sectors. Decomposition analysis of energy consumption combined with measures of the activity driving that consumption quantifies the effects of factors that shape energy consumption trends. The study finds that a decrease in energy intensity has had a very significant impact on reducing energy demand over the past 20 years. The largest impact can be observed in the industry sector where energy demand would have had increased by 358 trillion British thermal units (TBtu) if subsectoral energy intensities had remained at 1997 levels. Instead, energy demand actually decreased by 70 TBtu. In the "Building" sector, combined results from the "Service" and "Residential" subsectors suggest that energy demand would have increased by 264 TBtu (121 TBtu in the "Services" sector and 143 TBtu in the "Residential" sector) during the same period, 1997 to 2008. However, energy demand increased at a lesser rate, by only 162 TBtu (92 TBtu in the "Services" sector and 70 TBtu in the "Residential" sector). These energy intensity reductions can be indicative of energy-efficiency improvements during the past 10 years. The research presented in this report provides a basis for developing an energy-efficiency performance index to measure progress over time in the State of California.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Categorization of potential distributed energy resource (DER) opportunities in water and wastewater systems in California

This is an informal interim deliverable in the larger California Public Utilities Commission analytical support project. This document provide a high level categorization of potential distributed energy resource (DER) opportunities in water and wastewater systems in California. Future deliverables in this project will provide more detail on grid services that might be provided by the identified unit processes, a characterization of maturity and potential impacts to cost effectiveness, and an order of magnitude estimate of DER potential that may be practically achievable in California through water and wastewater systems informed by case studies in California and beyond.

13 HYDRO ENERGY↗
DOE OSTI2022

Comprehensive Review of California's Innovative Clean Transit Regulation: Phase I Summary Report

This report–prepared by NREL and UC Berkeley for the California Air Resources Board (CARB)–provides a comprehensive review conducted for implementation of the Innovative Clean Transit (ICT) regulation and deployment of zero-emission transit buses in California. The ICT regulation requires California transit agencies to begin transitioning to zero-emission vehicle technologies, defining an increasing percentage of new bus purchases that must be zero-emission buses (ZEBs) each year. The purchase requirements begin in 2023, increasing to a 100% ZEB purchase requirement beginning in 2029. This schedule is designed to result in 100% ZEB fleets statewide by 2040. The focus of the Phase I study was on implementation progress, status of standard-size transit buses, and the California transit industry's readiness to meet the 2023 ICT purchase requirements.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI1978

Plant Engineers Solar Energy Handbook: Southern California Region

Discussed in order after the introduction are solar components and systems (collectors, storage, service hot water systems, space heating with liquid and air systems, space cooling, heat pumps and controls); computer programs for system optimization; local solar and weather data; a description of buildings and plants in Southern California applying solar technology; current Federal and California solar legislation; standards, codes and performance testing information; a listing of manufacturers, distributors, and professional services available in Southern California region; and information access. Finally, solar design check lists for those engineers who wish to design their own systems. The program for the Solar Workshop for the Plant Engineer, March 30, 1978, Los Angeles, California is included.

14 SOLAR ENERGY↗
DOE OSTI2025

Deployment Potential of Concentrating Solar Power Technologies in California

As states within the United States respond to future grid development goals, there is a growing demand for reliable and resilient nighttime generation that can be addressed by low-cost, long-duration energy storage solutions. This report studies the potential of including concentrating solar power (CSP) in the technology mix to support California’s goals as defined in Senate Bill 100. A joint agency report study that determined potential pathways to achieve the renewable portfolio standard set by the bill did not include CSP, and our work provides information that could be used as a follow-up. This study uses a capacity expansion model configured to have nodal spatial fidelity in California and balancing-area fidelity in the Western Interconnection outside of California. The authors discovered that by applying current technology cost projections CSP fulfills nearly 15% of the annual load while representing just 6% of total installed capacity in 2045, replacing approximately 30 GWe of wind, solar PV, and standalone batteries compared to a scenario without CSP included. The deployment of CSP in the results is sensitive to the technology’s cost, which highlights the importance of meeting cost targets in 2030 and beyond to enable the technology’s potential contribution to California’s carbon reduction goals.

14 SOLAR ENERGY↗
NASA NTRS2015

Causes of the 2011-14 California Drought

The causes of the California drought during November-April winters of 2011/12-2013/14 are analyzed using observations and ensemble simulations with seven atmosphere models forced by observed SSTs. Historically, dry California winters are most commonly associated with a ridge off the west coast but no obvious SST forcing. Wet winters are most commonly associated with a trough off the west coast and an El Nino event. These attributes of dry and wet winters are captured by many of the seven models. According to the models, SST forcing can explain up to a third of California winter precipitation variance. SST forcing was key to sustaining a high pressure ridge over the west coast and suppressing precipitation during the three winters. In 2011/12 this was a response to a La Nina event, whereas in 2012/13 and 2013/14 it appears related to a warm west-cool east tropical Pacific SST pattern. All models contain a mode of variability linking such tropical Pacific SST anomalies to a wave train with a ridge off the North American west coast. This mode explains less variance than ENSO and Pacific decadal variability, and its importance in 2012/13 and 2013/14 was unusual. The models from phase 5 of CMIP (CMIP5) project rising greenhouse gases to cause changes in California all-winter precipitation that are very small compared to recent drought anomalies. However, a long-term warming trend likely contributed to surface moisture deficits during the drought. As such, the precipitation deficit during the drought was dominated by natural variability, a conclusion framed by discussion of differences between observed and modeled tropical SST trends.

California Drought↗
DOE OSTI2010

Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)

A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2010

The Influence of a CO2 Pricing Scheme on Distributed Energy Resources in California's Commercial Buildings

The Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) is working with the California Energy Commission (CEC) to determine the potential role of commercial-sector distributed energy resources (DER) with combined heat and power (CHP) in greenhouse gas emissions (GHG) reductions. Historically, relatively little attention has been paid to the potential of medium-sized commercial buildings with peak electric loads ranging from 100 kW to 5 MW. In our research, we examine how these medium-sized commercial buildings might implement DER and CHP. The buildings are able to adopt and operate various technologies, e.g., photovoltaics (PV), on-site thermal generation, heat exchangers, solar thermal collectors, absorption chillers, batteries and thermal storage systems. We apply the Distributed Energy Resources Customer Adoption Model (DER-CAM), which is a mixed-integer linear program (MILP) that minimizes a site?s annual energy costs and/or CO2 emissions. Using 138 representative mid-sized commercial sites in California, existing tariffs of major utilities, and expected performance data of available technologies in 2020, we find the GHG reduction potential for these buildings. We compare different policy instruments, e.g., a CO2 pricing scheme or a feed-in tariff (FiT), and show their contributions to the California Air Resources Board (CARB) goals of additional 4 GW CHP capacities and 6.7 Mt/a GHG reduction in California by 2020. By applying different price levels for CO2, we find that there is competition between fuel cells and PV/solar thermal. It is found that the PV/solar thermal adoption increases rapidly, but shows a saturation at high CO2 prices, partly due to limited space for PV and solar thermal. Additionally, we find that large office buildings are good hosts for CHP in general. However, most interesting is the fact that fossil-based CHP adoption also increases with increasing CO2 prices. We will show service territory specific results since the attractiveness of DER varies widely by climate zone and service territory.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2025

The anaerobic fungus Neocallimastix californiae shifts metabolism and produces melanin in response to lignin-derived aromatic compounds

Biological deconstruction of lignocellulose for sustainable chemical production offers an opportunity to harness evolutionarily specialized enzymes and organisms for industrial bioprocessing. While hydrolysis of cellulose and hemicellulose by CAZymes yields fermentable sugars, ligninolysis releases a heterogeneous mix of aromatic compounds that likely play a crucial role in shaping microbial communities and microbial metabolism. Here, we interrogated the metabolomic and transcriptomic response of a lignocellulolytic anaerobic fungus, Neocallimastix californiae, to a heterogeneous mixture of aromatic compounds derived from lignin. Through exposing the fungus to both a concentration it might experience in its native environment and an elevated concentration of alkaline lignin, we observe that N. californiae transforms vanillin and that supplying alkaline lignin at 0.125 g/L, alongside cellulose, enhances the growth and polysaccharide-degrading activity of N. californiae. Altogether, our results further suggest that vanillin consumption, increased polymer-degrading activity, increased metabolic activity, and transcriptomic remodeling of amino acid synthesis genes all coincide with increased melanin production by fungal cells. These observations challenge previous notions that aromatics from lignocellulose only inhibit the growth and polymer deconstruction capabilities of the biomass-degrading anaerobic fungi (Neocallimastigomycetes). This study demonstrates that anaerobic fungi have a complex relationship with aromatic chemicals derived from lignin and hemicellulose and shift their metabolism in response to the addition of lignocellulose-derived aromatics to their growth medium. Further, as no known pathways for the biochemical transformation of aromatics were detected in these organisms despite observed transcriptome remodeling in the presence of aromatics, we suggest they might encode novel biochemical routes for scavenging amino acid building blocks from aromatic monomers derived from hemicellulose side chains and lignin.

Anaerobic fungi↗
DOE OSTI2010

Feasibility Study of Economics and Performance of Solar Photovoltaics at the Stringfellow Superfund Site in Riverside, California

This report presents the results of an assessment of the technical and economic feasibility of deploying a photovoltaics (PV) system on the Stringfellow Superfund Site in Riverside, California. The site was assessed for possible PV installations. The cost, performance, and site impacts of different PV options were estimated. The economics of the potential systems were analyzed using an electricrate of $0.13/kWh and incentives offered by Southern California Edison under the California Solar Initiative. According to the assessment, a government-owned, ground-mounted PV system represents a technically and economically feasible option. The report recommends financing options that could assist in the implementation of such a system.

14 SOLAR ENERGY↗
DOE OSTI2017

Assessment of an atmospheric transport model for annual inverse estimates of California greenhouse gas emissions

Abstract Atmospheric inverse estimates of gas emissions depend on transport model predictions, hence driving a need to assess uncertainties in the transport model. In this study we assess the uncertainty in WRF‐STILT (Weather Research and Forecasting and Stochastic Time‐Inverted Lagrangian Transport) model predictions using a combination of meteorological and carbon monoxide (CO) measurements. WRF configurations were selected to minimize meteorological biases using meteorological measurements of winds and boundary layer depths from surface stations and radar wind profiler sites across California. We compare model predictions with CO measurements from four tower sites in California from June 2013 through May 2014 to assess the seasonal biases and random errors in predicted CO mixing ratios. In general, the seasonal mean biases in boundary layer wind speed (< ~ 0.5 m/s), direction (< ~ 15°), and boundary layer height (< ~ 200 m) were small. However, random errors were large (~1.5–3.0 m/s for wind speed, ~ 40–60° for wind direction, and ~ 300–500 m for boundary layer height). Regression analysis of predicted and measured CO yielded near‐unity slopes (i.e., within 1.0 ± 0.20) for the majority of sites and seasons, though a subset of sites and seasons exhibit larger (~30%) uncertainty, particularly when weak winds combined with complex terrain in the South Central Valley of California. Looking across sites and seasons, these results suggest that WRF‐STILT simulations are sufficient to estimate emissions of CO to up to 15% on annual time scales across California.

Bagley, Justin E.↗
DOE OSTI2017

Modeling the climate impacts of deploying solar reflective cool pavements in California cities

Solar reflective “cool pavements” have been proposed as a potential heat mitigation strategy for cities. However, previous research has not systematically investigated the extent to which cool pavements could reduce urban temperatures. In this study we investigated the climate impacts of widespread deployment of cool pavements in California cities. Using the Weather Research and Forecasting model, we simulated the current climate of California at 4 km spatial resolution. Comparing this simulation to 105 weather stations in California suggested an overall mean bias (model minus observation) of -0.30°C. Widespread pavement albedo increases of 0.1 and 0.4 in California cities were then simulated. Comparing temperature reductions for each scenario showed that the climate response to pavement albedo modification was nearly linear. Temperature reductions at 14:00 local standard time were found to be 0.32°C per 0.1 increase in grid cell average albedo. Temperature reductions were found to peak in the late morning and evening when (a) boundary layer heights were low and (b) solar irradiance (late morning) and heat accumulation in the pavement (evening) was high. Temperature reductions in summer were found to exceed those in winter, as expected. After scaling the results using realistic data-derived urban canyon morphologies and an off-line urban canyon albedo model, annual average surface air temperature reductions from increasing pavement albedo by 0.4 ranged from 0.18°C (Palm Springs) to 0.86°C (San Jose). We note the variation among cities was due to differences in baseline climate, size of the city, urban fraction, and urban morphology.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Potential benefits of cool walls on residential and commercial buildings across California and the United States: Conserving energy, saving money, and reducing emission of greenhouse gases and air pollutants

Solar-reflective “cool” walls reduce absorption of sunlight by the building envelope, which may decrease cooling load in warm weather and increase heating load in cool weather. Changes to annual heating, ventilation, and air conditioning (HVAC) energy use depend on climate, wall construction, wall orientation, building geometry, HVAC efficiency, and operating schedule. Changes to annual energy cost and energy-related emissions further vary with local energy prices and emission factors. In this work, we used EnergyPlus to perform over 100,000 whole-building energy simulations, spanning 10 different building categories, three building vintages, 16 California climate zones, and 15 United States (U.S.) climate zones. We find that cool walls yielded annual source energy, energy cost, and emission savings in all California climate zones and in warm U.S. (ASHRAE) climate zones. In California, annual whole-building HVAC energy cost savings were 4.0–27% in single-family homes, 0.5–3.8% in medium office buildings, and 0.0–8.5% in stand-alone retail stores. In warm U.S. climates—zones 1A (Miami, FL) through 4B (Albuquerque, NM)—annual HVAC energy cost savings were 1.8–8.3% in single-family homes, 0.3–4.6% in medium office buildings, and 0.5–11% in stand-alone retail stores. California and U.S. fractional source energy and emission savings were comparable to fractional energy cost savings. Per unit surface area modified, cool-wall savings often exceeded cool-roof savings because building codes typically prescribe much less wall insulation than roof insulation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗