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All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Energy Savings Results from Small Commercial Building Retrofits in the US

Small commercial buildings, or those comprising less than 50,000 square feet of floor area, represent 94% of U.S commercial buildings by count and consume approximately 8% of the nation’s primary energy; as such, they represent a largely unexploited opportunity for energy savings. Small commercial buildings also represent a large economic market—the National Institute of Building Sciences (NIBS) estimated the small commercial retrofit market at USD 35.6 billion. Despite the prominence of small commercial buildings and the economic opportunity for energy retrofits, many energy efficiency programs focus on large commercial buildings, and create efficiency solutions that do not meet the needs of the small commercial market. This paper presents an analysis of 34 small commercial case study projects that implemented energy efficiency retrofits. This paper contributes to the existing building retrofit body of knowledge in the following ways: (1) it identifies the decision criteria used by small commercial building stakeholders that decided to complete an energy retrofit; (2) it identifies the most commonly implemented efficiency measures in small commercial buildings, and discusses why this is the case; and (3) it provides empirical evidence about the efficacy of installing single energy efficiency measures (EEMs) compared to packages of EEMs in small commercial buildings by reporting verified energy savings. To the authors’ knowledge, this paper is the first to catalog decision criteria and energy savings for the existing small commercial buildings market, and this research illustrates that small commercial building decision-makers seem most motivated to retrofit their spaces by energy cost savings and operational concerns. Furthermore, small commercial building decision-makers opted to implement single-system retrofits in fifteen (15) of the thirty-four cases studied. Finally, this research documents the improved savings, in the small commercial buildings market, associated with a more integrated package of EEMs compared to a single-system approach, achieving approximately 10% energy savings for a single-system approach and more than 20% energy savings for integrated approaches. These savings translate to CO2 savings of 1,324,000 kgCO2/year to 2,647,000 kgCO2/year, respectively, assuming small commercial buildings are retrofit at a rate of 0.95% of the stock annually.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2015

Low-cost Radon Reduction Pilot Study

The U.S. Department of Energy's Building America research team Partnership for Advanced Residential Retrofits conducted a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation and living space floor assembly. Fifteen homes in the Champaign, Illinois, area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity measurements. Blower door and zone pressure diagnostics were conducted at each house. The treatments consisted of using air-sealing foams at the underside of the floor that separated the living space from the foundation and providing duct sealing on the ductwork that is situated in the foundation area. The hypothesis was that air sealing the floor system that separated the foundation from the living space should better isolate the living space from the foundation; this isolation should lead to less radon entering the living space from the foundation. If the hypothesis had been proven, retrofit energy-efficiency programs may have chosen to adopt these isolation methods for enhanced radon protection to the living space.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

SEE Action Guide for States: Evaluation, Measurement, and Verification Frameworks$-$Guidance for Energy Efficiency Portfolios Funded by Utility Customers

This guide describes frameworks for evaluation, measurement, and verification (EM&V) of utility customer–funded energy efficiency programs. The authors reviewed multiple frameworks across the United States and gathered input from experts to prepare this guide. This guide provides the reader with both the contents of an EM&V framework, along with the processes used to develop and update these frameworks.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Building America Case Study: Evaluation of Residential Integrated Space/Water Heat Systems, Illinois and New York (Fact Sheet)

This multi-unit field demonstration of combined space and water heating (combi) systems was conducted to help document combi system installation and performance issues that needed to be addressed through research. The objective of the project was to put commercialized forced-air tankless combi units into the field through local contractors that were trained by manufacturers and GTI staff under the auspices of utility-implemented Emerging Technology Programs. With support from PARR, NYSERDA and other partners, the project documented system performance and installations in Chicago and New York. Combi systems were found to save nearly 200 therms in cold climates at efficiencies between about 80% and 94%. Combi systems using third-party air handler units specially designed for condensing combi system operation performed better than the packaged integrated combi systems available for the project. Moreover, combi systems tended to perform poorly when the tankless water heaters operating at high turn-down ratios. Field tests for this study exposed installation deficiencies due to contractor unfamiliarity with the products and the complexity of field engineering and system tweaking to achieve high efficiencies. Widespread contractor education must be a key component to market expansion of combi systems. Installed costs for combi systems need to come down about 5% to 10% to satisfy total resource calculations for utility-administered energy efficiency programs. Greater sales volumes and contractor familiarity can drive costs down. More research is needed to determine how well heating systems such as traditional furnace/water heater, combis, and heat pumps compare in similar as-installed scenarios, but under controlled conditions.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Mind the Gap: Summary of Window Residential Retrofit Solutions

Improving the insulation, solar heat gain, and infiltration characteristics of windows in a home has the potential to significantly improve the overall thermal performance by reducing heat transfer through the window and also by decreasing infiltration of outdoor air into the home. As approximately 43% of existing homes still have single-pane clear windows (~50 million houses) and millions of other homes have only double-pane clear windows (Cort 2013), improving window performance also presents a significant opportunity for energy savings in the residential sector. Today, various energy-saving window retrofit opportunities are available to homeowners, ranging from window coverings and storm panels to highly-insulating triple-pane R-5 window replacements. Many of these technologies have been evaluated in the field, in the “Lab Homes” at Pacific Northwest National Laboratory, and through modeling to prove their cost-effectiveness and performance in different climate regions. Recently, the Pacific Northwest’s Regional Technical Forum approved a utility measure for low- emissivity storm windows based on such data. This action represents a watershed moment for increasing the variety and prevalence of fenestration options in utility programs, especially for the low-income demographic. This paper will review various window retrofit options, the most recent field test and modeling data regarding their performance and cost-effectiveness, and discuss future rating efforts. This information is useful for utilities and energy-efficiency program managers to help effectively implement incentive measures for these technologies.

HVAC↗
DOE OSTI2015

Stochastic Control of Energy Efficient Buildings: A Semidefinite Programming Approach

The key goal in energy efficient buildings is to reduce energy consumption of Heating, Ventilation, and Air- Conditioning (HVAC) systems while maintaining a comfortable temperature and humidity in the building. This paper proposes a novel stochastic control approach for achieving joint performance and power control of HVAC. We employ a constrained Stochastic Linear Quadratic Control (cSLQC) by minimizing a quadratic cost function with a disturbance assumed to be Gaussian. The problem is formulated to minimize the expected cost subject to a linear constraint and a probabilistic constraint. By using cSLQC, the problem is reduced to a semidefinite optimization problem, where the optimal control can be computed efficiently by Semidefinite programming (SDP). Simulation results are provided to demonstrate the effectiveness and power efficiency by utilizing the proposed control approach.

Ma, Xiao↗
DOE OSTI2018

The BayREN Integrated Commercial Retrofits (BRICR) Project: An Introduction and Preliminary Results

BayREN Integrated Commercial Retrofits (BRICR) is a DOE-funded project which aims to enhance the capacity of energy efficiency programs to recruit participants, develop retrofits, and measure outcomes in small and medium-sized commercial buildings, a sector notoriously hard to reach and expensive to serve, that accounts for 2/3 of US commercial floor space. To address these barriers, BRICR leverages existing incentives, financing, data, and open source software to facilitate two paths for comprehensive improvements: a deep energy retrofit, or serial upgrades integrated into capital improvement and maintenance cycles. BRICR is developing an integrated workflow for iterative energy modeling of commercial buildings for city energy program managers and auditors - starting with mass building-scale simulation based on public records and proceeding through audit, retrofit, and measurement and verification stages. BRICR builds on existing tools including LBNL’s CBES, NREL’s OpenStudio, PNNL’s Audit Template, and DOE’s BuildingSync and SEED PlatformTM. At each stage, BRICR uses available information to inform simulations (starting with public records but iteratively augmented with observations from energy program staff) to improve the quality of the models that inform decision making. This paper presents initial results from energy models of 1699 office and retail buildings in San Francisco. Building stock data from public records were translated to create a BuildingSync file for each building which was stored in SEED. Each BuildingSync file was then translated to multiple OpenStudio Workflow files for EnergyPlus simulation to estimate energy savings of energy conservation measures (ECM). Energy savings predictions for each ECM were written back to an updated BuildingSync file for each building and re-uploaded to SEED. The distribution of baseline energy simulations was calibrated against the publicly disclosed distribution of energy benchmarking data to increase confidence in results.

Piette, M↗
DOE OSTI2019

Solar-Reflective “Cool” Walls: Benefits, Technologies, and Implementation

Raising the albedo (solar reflectance) of a building’s walls reduces unwanted solar heat gain in the cooling season. This saves electricity and lowers peak power demand by decreasing the need for air conditioning. It can also cool the outside air, which can mitigate the urban heat island effect and also improve air quality by slowing the reactions that produce smog. This project quantified the energy savings, peak demand reduction, urban cooling, and air quality improvements attainable from solar-reflective “cool” walls in California; collaborated with industry to assess the performance of existing cool-wall technologies, and to develop innovative cool-wall solutions; and worked with state and federal government agencies, utilities, and industry to create a cool-wall infrastructure, including application guidelines, a product rating program, incentives, and building code credits. Simulations indicate that cool walls provide annual energy savings, peak demand reduction, annual emission reduction, and summer heat island mitigation benefits comparable to those yielded by cool roofs, and are helpful across California and in most of the southern half of the United States (that is, in U.S. climate zones 1—4). Natural exposure trials conducted at three sites in California and another three sites across the United States indicate that cool-wall materials tend to stay clean and reflective. Significant advances were made in novel cool-wall technologies, such as fluorescent cool pigments that expand the color palette for cool-wall products. We prepared guidelines for the climate- and building-appropriate use of cool walls, convened a stakeholder workshop, and created a working group. Ongoing efforts seek to introduce or expand cool-wall provisions in building energy standards, green building programs, and energy efficiency incentive programs, and to develop a cool-wall product rating system.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Solar-Reflective “Cool” Walls: Benefits, Technologies, and Implementation

Raising the albedo (solar reflectance) of a building’s walls reduces unwanted solar heat gain in the cooling season. This saves electricity and lowers peak power demand by decreasing the need for air conditioning. It can also cool the outside air, which can mitigate the urban heat island effect and also improve air quality by slowing the reactions that produce smog. This project quantified the energy savings, peak demand reduction, urban cooling, and air quality improvements attainable from solar-reflective “cool” walls in California; collaborated with industry to assess the performance of existing cool-wall technologies, and to develop innovative cool-wall solutions; and worked with state and federal government agencies, utilities, and industry to create a cool-wall infrastructure, including application guidelines, a product rating program, incentives, and building code credits. Simulations indicate that cool walls provide annual energy savings, peak demand reduction, annual emission reduction, and summer heat island mitigation benefits comparable to those yielded by cool roofs, and are helpful across California and in most of the southern half of the United States (that is, in U.S. climate zones 1—4). Natural exposure trials conducted at three sites in California and another three sites across the United States indicate that cool-wall materials tend to stay clean and reflective. Significant advances were made in novel cool-wall technologies, such as fluorescent cool pigments that expand the color palette for cool-wall products. We prepared guidelines for the climate- and building-appropriate use of cool walls, convened a stakeholder workshop, and created a working group. Ongoing efforts seek to introduce or expand cool-wall provisions in building energy standards, green building programs, and energy efficiency incentive programs, and to develop a cool-wall product rating system.

utility incentives↗
DOE OSTI2018

Final Technical Report: Commercial Advanced Lighting Control (ALC) Demonstration and Deployment

This three-year demonstration and deployment project sought to address market barriers to accelerating the adoption of Advanced Lighting Controls (ALCs), an underutilized technology with low market penetration. ALCs are defined as networked, addressable lighting control systems that utilize software or intelligent controllers to combine multiple energy-saving lighting control strategies in a single space (e.g., smart-time scheduling, daylight harvesting, task tuning, occupancy control, personal control, variable load-shedding, and plug-load control). The networked intelligent aspect of these systems allows applicable lighting control strategies to be combined in a single space, layered over one another, maximizing overall energy-savings. The project included five real building demonstrations of ALCs across the Northeast US region. The demonstrations provided valuable data and experience to support deployment tasks that are necessary to overcome market barriers. These deployment tasks included development of training resources for building designers, installers, and trades, as well as development of new energy efficiency rebates for the technology from Efficiency Forward’s utility partners. Educating designers, installers, and trades on ALCs is a critical task for reducing the cost of the technology that is currently inflated due to perceived complexity and unfamiliarity with how to design and install the systems. Further, utility and non-utility energy efficiency programs continue to relegate the technology to custom or ill-suited prescriptive program designs that do not effectively deploy the technology at scale. This project developed new, scalable rebate approaches for the technology. Efficiency Forward utilized their DesignLights Consortium® (DLC) brand and network of 81 DLC member utilities to develop and deploy the results of the project. The outputs of the project have included five published case studies, a six-hour ALC technology training curriculum that has already been deployed in five US states, and new rebates offered for the technology that have been deployed by a dozen utilities across the US. Widespread adoption of ALC technology in commercial buildings would provide tremendous benefits. The current market penetration of ALC systems is estimated at <0.1% in commercial buildings. If ALC systems were installed in all commercial buildings, approximately 1,051 TBtu of energy could be saved. This would translate into customer cost savings of approximately $10.7 billion annually.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

State Energy Efficiency Resource Standards: Design, Status, and Impacts

An energy efficiency resource standard (EERS) is a policy that requires utilities or other entities to achieve a specified amount of energy savings through customer energy efficiency programs within a specified timeframe. EERSs may apply to electricity usage, natural gas usage, or both. This paper provides an overview of the key design features of EERSs for electricity, reviews the variation in design of EERSs across states, and provides an estimate of the amount of savings required by currently specified EERSs in each state. As of December, 2013, 23 states have active and binding EERSs for electricity. We estimate that state EERSs will require annual electricity savings of approximately 8-11% of total projected demand by 2020 in states with EERSs, however the level of savings targeted by the policies varies significantly across states. In addition to the variation in targeted savings, the design of EERSs varies significantly across states leading to differences in the suite of incentives created by the policy, the flexibility of compliance with the policy, the balance of benefits and costs of the policy between producers and consumers, and the certainty with which the policy will drive long-term savings.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Packaged Combined Heat and Power Technology Overview and Market Profile

Combined heat and power (CHP), sometimes referred to as cogeneration, is an efficient and clean approach to generating electric power and useful thermal energy onsite from a single fuel source, offering reliable and affordable energy services to businesses and institutions. Furthermore, CHP provides a cost effective opportunity to improve the environmental footprint and resilience of industrial and commercial facilities across the United States. CHP equipment can be custom-engineered or installed as a predesigned and assembled package. A packaged CHP system is a standardized, pre-engineered system that includes all equipment, piping, wiring, and ancillary components to deliver electricity and thermal energy to a host facility with minimal onsite engineering and design time. Packaged CHP systems can be shipped as single or multiple modules with standard interconnections (e.g., fuel; electrical; thermal—hot water, steam, and/or chilled water), which simplifies installation and reduces the costs associated with the project. Most containerized or single packaged CHP system offerings range from 10 kW to 3 MW in capacity. Packaged CHP systems are extending the operating, efficiency, and emissions benefits of CHP to nontraditional markets in commercial, institutional, multifamily, light manufacturing, government, and military applications. These markets tend to be served by smaller systems (less than 5 MW) that are conducive to pre-engineered packaging and/or modularization. Many of these sectors have limited CHP experience and technical resources to adequately evaluate, install, and maintain onsite CHP systems. The introduction of packaged CHP offerings from experienced CHP Packagers and Solution Providers has accelerated CHP adoption, lowered energy costs, reduced emissions, and strengthened energy resilience in these sectors. In 2019, the US Department of Energy (DOE) launched the Packaged CHP eCatalog to promote increased acceptance of efficient, cost-effective CHP in these applications. The Packaged CHP eCatalog is a web-based, searchable platform that hosts DOE-recognized packaged CHP systems with features designed to reduce economic and performance risks for designers, developers, owners, and facility operators interested in installing CHP. DOE established the Packaged CHP Accelerator at the same time to help launch and publicize the eCatalog, and to validate project performance, cost, and installation time of CHP packages across a variety of applications. Accelerator efforts documented installed cost reductions and installation time reductions of more than 20% for packaged CHP systems over 100 kW compared with custom-engineered systems. The Packaged CHP Accelerator and eCatalog established a peer-to-peer network connecting public and private sector partners including utilities, state energy offices, and energy efficiency program administrators interested in promoting cost-effective, efficient CHP systems, Packagers, and Solution Providers. Feedback from these partners, along with input from DOE’s CHP Technical Assistance Partnerships (CHP TAPs), was critical in understanding the current market for packaged CHP technologies, stimulating investment in these technologies, and guiding future directions for packaged CHP systems and their applications. This report provides background on packaged CHP systems, an overview of their benefits, a profile of current packaged CHP installations, and a summary of future market trends; this report is intended for facility owners, project developers, engineers, policymakers, and other stakeholders looking to increase the adoption of efficient, flexible, and resilient packaged CHP systems.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

New Whole-House Solutions Case Study: Northwest Energy Efficient Manufactured Housing Program High-Performance Test Homes - Pacific Northwest

This project represents the third phase of a multi-year effort to develop and bring to market a High Performance Manufactured Home (HPMH). In this project, the Northwest Energy Efficient Manufactured Housing Program worked with Building America Partnership for Improved Residential Construction and Bonneville Power Administration to help four factory homebuilders build prototype zero energy ready manufactured homes, resulting in what is expected to be a 30% savings relative to the Building America Benchmark. (The actual % savings varies depending on choice of heating equipment and climate zone). Previous phases of this project created a HPMH specification and prototyped individual measures from the package to obtain engineering approvals and develop preliminary factory construction processes. This case study describes the project team's work during 2014 to build prototype homes to the HPMH specifications and to monitor the homes for energy performance and durability. Monitoring is expected to continue into 2016.

BA-PIRC↗
DOE OSTI2022

Potential State Regulatory Pathways to Facilitate Low-Carbon Fuels

States and the federal government are increasingly engaged in the challenges around decarbonizing the electric grid. In particular, regulators, consumers, stakeholders, and utilities recognize the need to carefully consider the role natural gas will play in a decarbonized future. A variety of technology and policy options to reduce greenhouse gas emissions associated with natural gas use are available, including energy efficiency programs, demand reduction tools, strategic electrification, and strategies to reduce emissions from natural gas production, transportation, and consumption. Low-carbon fuels – mainly renewable natural gas (RNG) and clean hydrogen – are being considered an important component of decarbonization goals. RNG and hydrogen may be able to meaningfully reduce emissions from processes independent of geologic natural gas, displacing emissions of methane, a powerful greenhouse gas. Although RNG and hydrogen are not cost-competitive today with geologic natural gas and are smaller in scale and potential than other decarbonization options, they can be explored as potential critical tools to decarbonize sectors that are difficult to electrify or shift off of natural gas entirely, such as air travel, industrial processes, maritime transport, long-distance trucking, space heating on cold days, and railroads (Nadel, 2022). The role of this report is to provide informational context for state utility regulators to understand the impacts of and challenges associated with broader integration of low-carbon fuels, followed by examples of state regulatory actions taken to date to facilitate the development of low-carbon fuels. Setting clear guidance to calculate the environmental benefits of low-carbon fuels and continuing federal and state investments in research and development to reduce costs relative to fossil fuels will be important steps to take to signal the desire to grow the market for these fuels. State public utility commissions may play a key role in setting regulatory frameworks for low-carbon fuels and ensuring that ratepayer funds, if utilized, are done so to further the public interest. This report is intended to summarize decisions that states have made to date on low-carbon fuels. In the spirit of understanding the current market and sharing information, this report provides success stories, and lessons learned across states as regulators implement varying strategies to achieve decarbonization objectives while maintaining their focus on affordability, safety, and reliability of the energy system. The report begins with an introduction of the role of natural gas in the U.S. economy (Section I) and background information on natural gas use, decarbonization, and low-carbon fuels (Section II). Next, the report describes the current market by discussing the scale of current production, emissions intensity, resource potential, and costs of low-carbon fuels compared to geologic natural gas (Section III). Following these sections, the report describes four strategies states have employed to facilitate low-carbon fuels: opening exploratory dockets, approving voluntary tariffs for customers, approving interconnection tariffs for producers, and considering portfolio-wide procurement targets (Section IV). This section lists states that have taken actions in each category, citing utility filings, commission decisions, stakeholder comments, and other relevant sources. Finally, the report concludes with suggested questions regulators may wish to consider regarding low-carbon fuels, in the interest of preparing to make decisions in the future (Section V). These questions include: Are there existing regulatory or technical barriers to voluntary purchases of low-carbon fuels? Can customers work with utilities to procure low-carbon fuels; are producers able to interconnect projects without significant barriers to entry? Should the infrastructure and/or commodity costs of low-carbon fuels be socialized among all ratepayers, or borne solely by the large commercial and industrial (C&I) customers currently driving the market? Should regulated natural gas and/or electric utilities own and operate low-carbon fuel production? How should regulators consider the unique decarbonization potential of low-carbon fuels, particularly for hard-to-abate sectors, in decision-making? Is additional direction or clarity from state policymakers needed? What no-regrets approaches can help facilitate both near-term RNG development and long-term development of hydrogen and other zero-carbon fuels? We collectively wish to express our gratitude to the U.S. Department of Energy, Office of Fossil Energy and Carbon Management, for supporting this report and other technical assistance resources for state regulators on natural gas topics. State regulators operate under a variety of policy environments, and states have vastly different types of energy resources, infrastructure, and customers. While there is no optimal regulatory, policy, or technological solution that will be successful in every state, state regulators can benefit by exchanging lessons learned with their peers across the country. We look forward to continued engagement with our fellow commissioners, commission staff, NARUC, the U.S. Department of Energy, and other stakeholders to develop sound regulation in the public interest.

03 NATURAL GAS↗
DOE OSTI2016

A Field Study of Wall Furnace Venting and Coincident Exhaust Fan Usage in 16 Northern California Apartments

To inform efforts to improve combustion appliance testing in residential energy efficiency programs, we studied the frequency of coincident fan use and depressurization-induced downdrafting and spillage from atmospherically vented (i.e., natural draft) wall furnaces in airtight apartments. Indoor environmental conditions, heating appliance operation, use of exhaust fans, and cooking with stovetop or oven were monitored for approximately three weeks each in 16 apartment units in two buildings in Northern California. Apartments also were assessed using standard combustion appliance safety test methods and enhanced protocols. Monitoring occurred in February and March of 2016, with heating demand corresponding to 7.3 ± 0.5 heating degree-days at a 65ºF reference temperature. Most of the furnaces spilled combustion products when the apartments were depressurized in the “worst-case” challenge condition of all exhaust fans operating at their highest settings and all windows closed. Many also spilled under less challenging conditions (e.g., with kitchen exhaust fan on low and bathroom fan operating). On average, bathroom exhaust fans were operated 3.9% of monitored minutes (13.5% max), and cooking (burner or kitchen fan operation) occurred 4.6% of minutes (max 13.3%). Event lengths averaged 17 minutes (max 540) and 34 minutes (max 324), respectively. Their coincident operation averaged 0.34% of minutes (max 2.0%), with average event length of 13 minutes (max 92 minutes). This suggests that the operation of apartment units at or near the currently used worst-case challenge condition is quite rare. Wall furnace burners operated an average of 2.8% of minutes (max of 8.9%), with average burner cycle length of 14 minutes (max 162). Coincident bath fan use, cooking and wall furnace operation was very rare, occurring only a handful of times across all apartments. The highest rate was 0.075% of monitored minutes in one apartment, and the longest event length was 12 minutes. Exhaust fan operation in this study may have been more frequent than typical as participants were asked to use an exhaust fan whenever cooking or bathing. Consistent with the low levels of coincident operation, unambiguous spillage occurred in only 4 apartments and the longest event was 5 minutes. The frequency of partial spillage is unknown, owing to a lack of a clear signal from monitored parameters. Downdrafting during exhaust fan use occurred in all 13 of the apartments with relevant data, and 9 of these units had 10 or more events. Exhaust fans also sometimes led to weakened draft, even if downdrafting did not occur. Each unambiguous spillage event identified in the study was immediately preceded by downdrafting. The observed occurrence of downdrafting and spillage may have been impacted in those apartments with the most severe drafting problems (i.e., appliances spilled combustion pollutants under ‘natural’ test conditions), because occupants in these units were instructed to open windows whenever using the kitchen exhaust fan.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

ARC algorithm: A novel approach to forecast and manage daily electrical maximum demand

This paper proposes an innovative algorithm for predicting short-term electrical maximum demand by using historical demand data. The ability to recognize in peak demand pattern for commercial or industrial customers would propose numerous direct and indirect benefits to the customers and utility providers in terms of demand reduction, cost control, and system stability. Prior works in electrical maximum demand forecasting have been mainly focused on seasonal effects, which is not a feasible approach for industrial manufacturing facilities in short-term load forecasting. The proposed algorithm, denoted as the Adaptive Rate of Change (ARC), determines the logarithmic rate-of-change in load profile prior to a peak by postulating the demand curve as a stochastic, mean-reverting process. The rationale behind this analysis, is that the energy efficient program requires not only demand estimation but also to warn the user of imminent maximum peak occurrence. This paper analyzes demand trend data and incorporates stochastic model and mean reverting half-life to develop an electrical maximum demand forecasting algorithm, which is statistically evaluated by cross-table and F-score for three different manufacturing facilities. Lastly, the aggregate results show an overall accuracy of 0.91 and a F-score of 0.43, which indicates that the algorithm is effective predicting peak demand in predicting peak demand.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2014

Data-Driven Benchmarking of Building Energy Efficiency Utilizing Statistical Frontier Models

Frontier methods quantify the energy efficiency of buildings by forming an efficient frontier (best-practice technology) and by comparing all buildings against that frontier. Because energy consumption fluctuates over time, the efficiency scores are stochastic random variables. Existing applications of frontier methods in energy efficiency either treat efficiency scores as deterministic values or estimate their uncertainty by resampling from one set of measurements. Availability of smart meter data (repeated measurements of energy consumption of buildings) enables using actual data to estimate the uncertainty in efficiency scores. Additionally, existing applications assume a linear form for an efficient frontier; i.e.,they assume that the best-practice technology scales up and down proportionally with building characteristics. However, previous research shows that buildings are nonlinear systems. This paper proposes a statistical method called stochastic energy efficiency frontier (SEEF) to estimate a bias-corrected efficiency score and its confidence intervals from measured data. The paper proposes an algorithm to specify the functional form of the frontier, identify the probability distribution of the efficiency score of each building using measured data, and rank buildings based on their energy efficiency. To illustrate the power of SEEF, this paper presents the results from applying SEEF on a smart meter data set of 307 residential buildings in the United States. SEEF efficiency scores are used to rank individual buildings based on energy efficiency, to compare subpopulations of buildings, and to identify irregular behavior of buildings across different time-of-use periods. SEEF is an improvement to the energy-intensity method (comparing kWh/sq.ft.): whereas SEEF identifies efficient buildings across the entire spectrum of building sizes, the energy-intensity method showed bias toward smaller buildings. The results of this research are expected to assist researchers and practitioners compare and rank (i.e.,benchmark) buildings more robustly and over a wider range of building types and sizes. Eventually, doing so is expected to result in improved resource allocation in energy-efficiency programs.

Kavousian, A↗
DOE OSTI2014

Cost-of-Service Segmentation of Energy Consumers

Uncertainty in consumption is a key challenge at energy utility companies, which are faced with balancing highly stochastic demand with increasingly volatile supply characterized by significant penetration rates of intermittent renewable sources. This paper proposes a methodology to quantify uncertainty in consumption that highlights the dependence of the cost-of-service with volatility in demand. We use a large and rich dataset of consumption time series to provide evidence that there is a substantial degree of high-level structure in the statistics of consumption across users which may be partially explained by certain characteristics of the users. To uncover this structure, we propose a new technique for extracting typical statistical signatures of consumption-energy demand distributions (EDDs)-that is based on clustering distributions using a fast, approximated algorithm. We next study the factors influencing the choice of consumption signature and identify certain types of appliances and behaviors related to appliance operation that are most predictive. Finally, we comment on how structure in consumption statistics may be used to target residential energy efficiency programs to achieve greatest impact in curtailing cost of service.

Albert, A↗