Energy Technologies

Decarbonizing the US residential building stock requires a substantial acceleration in home energy upgrades. Numerous barriers exist to accelerating adoption of efficient and electric building technologies, but foremost among these is high upfront costs. This study uses an industry survey delivered to a sample of home energy professionals to examine promising cost reduction strategies across a range of project types, including HVAC, water heating, and envelope/insulation projects. The survey included quantitative and qualitative questions to collect evidence on the estimated cost reduction potential of these strategies and their likelihood of use in the construction industry. The 167 survey respondents included contractors, energy consultants, architects, manufacturers, and others with experience in delivering energy upgrades in single-family and multifamily buildings in the US. Results show that significant cost reductions are achievable by minimizing additional infrastructure costs (such as replacing electric panels), streamlining project planning/management, and deploying innovations that simplify installation. We find that for a typical deep retrofit project, including heat pumps for space and water heating in addition to envelope upgrades, the strategies could result in a total installed cost reduction of nearly 50 %, dramatically improving the customer economics of such a project. This research makes a novel contribution to the literature on strategies to reduce the costs of residential retrofits. We discuss how our study's insights on the highest-value cost reduction strategies for home energy upgrades can further accelerate their uptake in the US housing stock.

This paper introduces a portable framework for developing, scaling and maintaining energy management and information systems (EMIS) applications using an ontology-based approach. Key contributions include an interoperable layer based on Brick schema, the formalization of application constraints pertaining metadata and data requirements, and a field demonstration. The framework allows for querying metadata models, fetching data, preprocessing, and analyzing data, thereby offering a modular and flexible workflow for application development. Its effectiveness is demonstrated through a case study involving the development and implementation of a data-driven anomaly detection tool for the photovoltaic systems installed at the Politecnico di Torino, Italy. During eight months of testing, the framework was used to tackle practical challenges including: (i) developing a machine learning-based anomaly detection pipeline, (ii) replacing data-driven models during operation, (iii) optimizing model deployment and retraining, (iv) handling critical changes in variable naming conventions and sensor availability (v) extending the pipeline from one system to additional ones.

Assessing the emissions of plug-in hybrid electric vehicle (PHEV) operations is crucial for accelerating the carbon–neutral transition in the passenger car sector. This study is the first to adopt a bottom-up model to measure the real-world energy use and carbon dioxide emissions of China's top twenty selling PHEV models across different regions from 2020 to 2022. The results indicate that (1) the actual electricity intensity of the best-selling PHEV models (20.2–38.2 kWh/100 km) was 30–40 % higher than the New European Driving Cycle values, and the actual gasoline intensity (4.7–23.5 L/100 km) was 3–6 times greater than the New European Driving Cycle values. (2) The overall energy use of the best-selling models varied among different regions, and the energy use from 2020 to 2022 in Southern China was double that Northern China and the Yangtze River Middle Reach. (3) The top-selling models emitted 4.7 megatons of carbon dioxide nationwide from 2020 to 2022, with 1.9 megatons released by electricity consumption and 2.8 megatons released by gasoline combustion. Furthermore, targeted policy implications for expediting the carbon–neutral transition within the passenger car sector are proposed. In essence, this study explores and compares benchmark data at both the national and regional levels, along with performance metrics associated with PHEV operations. The main objective is to aid nationwide decarbonization efforts, focusing on carbon reduction and promoting the rapid transition of road transportation toward a net-zero carbon future.

Energy reporting is the principle that all energy-using devices in buildings should be able to track their own energy use and report this to the local network. Energy reporting can provide building owners with easy access to highly granular energy use data. This report makes the case that energy reporting should become a free basic feature of all devices, and reports on a project intended to move us towards that goal. The project collected a set of demonstration devices with energy reporting features, including products that were modified by the project team or the manufacturer, or are already available for sale. To show these devices operating live at meetings and conferences, the team created a management system that queries the energy reporting devices for their data, stores the data, and displays it in compelling visualizations. The devices covered a wide range, including heating, ventilation, and air conditioning (thermostat and air purifier); lighting (individual bulb, task light, and auto-dimming overhead light); a vehicle charger; a water heater; electronics (notebook personal computer and universal serial bus charger); and three external meters (one integral with a dimming light switch). The demonstration uses a variety of communication protocols. The report reviews existing communication protocols that support energy reporting and describes how to use them with a proposed reference data model for energy reporting. It also assesses ways that energy codes and standards processes can be leveraged to drive energy reporting technology into the market. Energy reporting could ultimately save California on the order of 2.5 terawatt-hours per year and about $0.8 billion per year. Energy reporting is a highly practical technology with minimal (sometimes no) cost to consumers and manufacturers. This report discusses creation of the energy reporting devices themselves, analysis and recommendations for data models and protocols for energy reporting, and energy codes and standards implications of energy reporting technology. While energy reporting does not directly save energy, it provides information for better decision-making to save energy in changing equipment operation, maintenance, and replacement.

Increasing the efficiency and flexibility of electricity demand is necessary for ensuring a cost-effective and reliable transition to zero-carbon electricity systems. Such demand-side management (DSM) resources have been procured by utilities for decades via energy efficiency and demand response programs; however, the key drivers of program enrollment and customer participation levels remain poorly understood — even as governments and grid planners seek to scale up the deployment of DSM assets to meet climate targets. Here we systematically review the evidence on multiple factors that may influence customer enrollment and participation in building DSM programs, focusing primarily on residential and commercial buildings. We examine the contexts in which relationships between DSM factors and outcomes are most often explored and with which methods; we also score the strength, direction, and internal consistency of each factor's reported impact on the enrollment and participation outcomes. We find that studies most commonly assess the effects of economic incentives for load flexibility on program participation levels, often using simulation-based methods in lieu of measured data. Few studies focus on program enrollment outcomes or regulatory drivers of either enrollment or participation, and gaps are also evident in the coverage of emerging DSM opportunities like load electrification. Removal of structural barriers (e.g., the lack of controls infrastructure) and the use of third party services (e.g., load aggregators) are the factors with the largest positive impacts on DSM outcomes, but no single factor emerges as clearly most impactful. For a given factor, the range of reported impacts typically varies widely across the relevant studies reviewed. Our findings provide a snapshot of the state of knowledge about building DSM and customer decision-making, and they expose key gaps in understanding that must be filled if building DSM is to expand as a critical resource for operating clean power grids.

Direct Heating Equipment (DHE) is a type of space heating appliance that supplies warm air directly to the space where it is installed. It has been estimated that DHE is the primary and/or secondary source of space heating in 16% of households in California and that one-third of this fleet was installed more than 20 years ago. In addition, DHE is rarely maintained and is repaired only in extreme situations. Old DHE that is still in use has energy and emission implications. We evaluated 12 DHE units in the combustion laboratory at Lawrence Berkeley National Laboratory. Of those, eight were low-efficiency units removed from homes in California, and four were new, high-efficiency units. We found that, in most cases, the amount of natural gas used by a unit is consistent with the input rate of the model. We also found that, except for two high-efficiency models with ultra-low NOx burners, the NOx emissions from both the low- and high-efficiency models were very similar. Emissions of CO and CH4 are relatively uniform across models, except for two high-efficiency models that exhibit higher emissions of these gases. Additionally, many piloted units produced non-negligible amounts of CO and CH4 during stand-by periods, when only the pilot was lit. In general, our results are consistent with results from another study with similar scope.

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. ElectroCell Systems offers a skid-mounted, electrochemical based, side-stream filtration system. Facility and Technology Description and Scope This study evaluated the performance of an ElectroCell water treatment system at Toyota Motor Manufacturing Mississippi compared to an existing centrifugal-based filtration system from Lakos. The incumbent technology uses centrifugal principles to eliminate TSS from cooling tower water. In contrast, the ElectroCell system employs a multistage electrochemical process using low-voltage and high-voltage ionizers to generate an electrostatic field to treat the water. The scope of the evaluation included six chillers, each rated at 2,000 tons, three cooling tower cells, three air compressors (one screw at 702 horsepower and two centrifugal at 1,860 horsepower), and the relevant water treatment systems. Study Design and Objectives The evaluation’s goal was to assess the impact of the ElectroCell filtration system on energy, water, and chemical usage in the chilled water and compressed air systems with a cooling tower loop. The following are some of ElectroCell Systems’ claims and reasonings that were stated in their application and used as the basis for ITV evaluation: • Water usage reduction. The electrochemical-based system removes particulate down to 1 micron, which is an improvement from most filtration systems. In theory, less particulate in the loop should reduce the need for blowdown and in turn makeup water. • Energy reduction. The system minimizes scaling, resulting in less fouling and improved heat transfer within the system, leading to reduced energy U.S. Department of Energy | Office of Energy Efficiency & Renewable Energy vii Field Validation of Electrochemical Water Filtration System on an Open Loop Cooling Tower at Toyota Motor Manufacturing Plant in Blue Springs, Mississippi consumption at chillers, air compressors, and cooling towers. It also collapses laminar boundaries of the water, leading to better heat transfer. • Chemical usage reduction. The system decreases the reliance on chemicals for water treatment by removing finer particulate compared to traditional filtration systems, thereby reducing the required chemical treatment to maintain water quality. Additionally, with less blowdown, and in turn less makeup water, less water needs to be chemically treated. Methodology The evaluation methodology followed a measurement and verification strategy based on the International Performance Measurement and Verification Protocol Option B— utilizing a retrofit isolation method with all parameter measurements—through comprehensive measurements and analyses of the affected systems. The objective was to compare energy, water, and chemical treatment use with the ElectroCell System compared to the incumbent centrifugal filtration system. Our analysis relied on field data to construct predictive models for energy, water, and chemical treatment use to assess the impact of the proposed technology. Data was collected from February 2022 to February 2023, when the centrifugal system operated, and from February 2021 to February 2022, when the ElectroCell System ran.1 The methodology involved the development of mathematical models for various systems to study the impact from different aspects: • Energy Model. This model predicted electricity consumption based on chilled water load and condenser water entering temperature for each of the chillers. It predicted cooling tower fan energy based on the cooling tower heat of rejection and approach temperature. The electricity consumed by the compressed air system was modeled based on compressed air flow and pressure. The electricity consumed by the respective filtration systems was also considered based on metered data throughout the entire evaluation period. • Water Model. The water model predicted makeup water use based on cooling tower heat of rejection, ash house recovery volume, and makeup water total dissolved solids. • Chemical Treatment Model. This model calculated the chemical treatment costs per kilogallon of blowdown rate for each of the inhibitors and biocides. Each model’s goodness-of-fit characteristics were evaluated to ensure they met International Performance Measurement and Verification Protocol criteria. The energy, 1 The ElectroCell system was installed in August 2018. Data was collected about its operation from February 2021 to February 2022, at which point the incumbent centrifugal system was operated and data collected about its performance for a year, from February 2022 to February 2023. Toyota Motor Manufacturing Mississippi then switched back to the ElectroCell system after the evaluation. U.S. Department of Energy | Office of Energy Efficiency & Renewable Energy viii Field Validation of Electrochemical Water Filtration System on an Open Loop Cooling Tower at Toyota Motor Manufacturing Plant in Blue Springs, Mississippi water, and chemical impacts were determined by comparing actual use with the centrifugal system to modeled use with the ElectroCell system. Project Results/Findings Based on our analysis, the energy consumption associated with the chillers showed a reduction ranging from 1.1%–1.4%, while the energy impact associated with the air compressors showed an improved efficiency of 2.9%–3.3% compared to baseline. The water analysis showed 8%–15% less makeup water usage and 45% less chemical treatment use. It should be noted that while the evaluation was normalized to all pertinent available factors using rigorous measurement and verification approaches and sound statistical techniques, there may have been other unknown factors outside of the evaluation boundary that could have influenced the results. These findings are based on the evaluation of this technology at the selected site and its specific configuration and set of operating conditions. The performance of filtration systems depends on site-specific factors like existing equipment conditions, ambient air quality, particulate matter presence, and seasonal variations. It is influenced by wet bulb temperature and the quality of makeup water, including hardness, pH, and TDS levels, all of which play a significant role in water and chemical usage and require careful consideration for implementation.

The built environment is a complex ecosystem of social institutions and physical infrastructures. Innovation and entrepreneurship in the building industry are critical levers for market transformation toward equitable climate action. However, climate tech innovation for the built environment is not moving fast enough for global needs, and it lacks fundamental diversity, leading to inequitable outcomes. IMPEL (Incubating Market-propelled Entrepreneurial-mindset at the Labs and Beyond) - a U.S. Department of Energy incubator–addresses these critical issues. Over five years, IMPEL has enabled 250 innovators, including 55% women and diverse founders, to accelerate their buildings and clean energy technologies towards market and climate impact. IMPEL provides access to strategic mentoring and coaching, carbon tools training, testbeds, and powerful public-private pipelines, including industry demonstrations, non-dilutive grants, and venture capital networks. The IMPEL innovation ecosystem has accelerated the pace of innovation and market adoption of building decarbonization technologies. In this paper, leverage the IMPEL stakeholder ecosystem - from innovators to investors and product industry to policymakers - to analyze the critical barriers to decarbonization still encountered in the building industry. We study the IMPEL approach and highlight lessons learned that benefit young businesses pursuing innovative building and building-edge energy technologies to develop new ideas and products. Finally, we propose a ‘market forming’ framework to improve the quality and efficiency of the entrepreneurial ecosystem in the building industry. This framework could scale vetted technologies and the participation of diverse founders to de-risk the climate tech