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At least 739 records · Page 41

Targeting 100! Advanced Energy Efficient Building Technologies for High Performance Hospitals: Executive Summary.

This research, Targeting 100!, provides a conceptual framework and decision-making structure at a schematic design level of precision for hospital owners, architects and engineers to radically reduce energy use in hospitals. Following the goals of Architecture 2030 and The 2030 Challenge, it offers access to design strategies and the cost implications of those strategies for new hospitals to utilize 60% less energy. The name, Targeting 100!, comes from the 2030 Challenge energy reduction goal for hospitals; a 60% energy use reduction from typical acute care hospital targets approximately 100 KBtu/SF Year, thus the name “Targeting 100!”. Targeting 100! was developed through funding partnerships with the US Department of Energy and the Northwest Energy Efficiency’s BetterBricks Initiative. The technical team was led by the University of Washington Integrated Design Lab supported by deep collaboration with Solarc Architecture and Engineering, TBD Cost Consultants, and NBBJ Architecture. Through extensive research and design development, Targeting 100! provides a framework for developing high performance healthcare projects today and into the future. An online tool houses a Targeting 100! knowlegebase and roadmap. It can be accessed at: www.idlseattle.com/t100. The webtool is structured from high-level overview materials to detailed library with modeling inputs and outputs, providing a comprehensive report of the background, data, and outcomes from the project.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Dynamic Undervolting to Improve Energy Efficiency on Multicore X86 CPUs

Chip manufacturers introduce redundancy at various levels of CPU design to guarantee correct operation, even for worst-case combinations of non-idealities in process variation and system operating conditions. This redundancy is implemented partly in the form of voltage margins. However, for a wide range of real-world execution scenarios these margins are excessive and merely translate to increased power consumption, hindering the effort towards higher-energy efficiency in both HPC and general purpose computing. Our study on the x86-64 Haswell and Skylake multicore microarchitectures reveals-wide voltage margins, which vary across different microarchitectures, different chip parts of the same microarchitecture, and across different workloads. We find that it is necessary to quantify-voltage margins using multi-threaded and multi-instance workloads, as characterization with single-threaded and single-instance workloads that do not stress the CPU to its full capacity typically identifies overly optimistic margins that lead to errors when applied in realistic program execution scenarios. In addition, we introduce, deploy and evaluate a run-time governor that dynamically reduces the supply voltage of modern multicore x86-64 CPUs. Our governor employs a model that takes as input a set of performance metrics which are directly measurable via performance monitoring counters and have high predictive value for the minimum tolerable supply voltage (V min ), to predict and apply the appropriate reduction for the workload at hand. Compared with the conventional DVFS governor, our approach in this study achieves up to 42 percent energy savings for the Skylake family and 34 percent for the Haswell family for complex, real-world applications.

97 MATHEMATICS AND COMPUTING↗

SMART Scale An Innovative Program Accelerating the Energy Efficiency Market

Small business is a major component of the American economy. More than half of all private sector workers in this country are employed by small businesses and nearly two-thirds of the new jobs generated in the last ten years were created in this sector. Studies have shown that buildings of less than 50,000 square feet represent 94% of the commercial sector and half of all non-residential floor space in the United States. The future of the American economy relies on a vibrant, robust, and profitable small business community. Small and mid-sized businesses (SMB) can increase their profitability by reducing their operating costs through energy efficiency. The SMART Scale program delivers deep retrofits that maximize energy and cost savings for the SMB market and can be adapted throughout the country in markets of all sizes. For the past 14 years, Ecology Action has been perfecting a Direct Install (DI) program for the SMB market that offers this sector the type of sophisticated, comprehensive energy saving opportunities that were previously available only to large commercial and industrial customers. The DI 2.0 model that Ecology Action has administered for several public and investor-owned California utilities, and most recently for the Sacramento Municipal Utilities District (SMUD), provides the template for a successful retrofit program that can address the unique barriers faced by the SMB sector and achieve a greater impact than traditional DI programs. The impressive results produced by the DI 2.0 program prompted the US Department of Energy to award Ecology Action a $2 million grant in 2013 to create, demonstrate and roll out a replicable model for delivering deep retrofits to small commercial buildings. The grant enabled Ecology Action to build on the success of DI 2.0 by incorporating improvements into the model, market-testing it and designing a costeffective method of achieving significant energy savings for small businesses across the country.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Air quality and comfort constrained energy efficient operation of multi-zone buildings

Maintaining indoor air quality (IAQ) through effective ventilation is essential for the well-being and productivity of building occupants. Control strategies aimed at improving the efficiency of heating, ventilation and air conditioning (HVAC) systems must jointly determine ventilation and heating and cooling processes. Here, in this paper, we study the problem of minimizing the energy consumption of the HVAC system in a multi-zone building, while meeting thermal comfort and IAQ requirements. We first perform a steady state analysis of the zonal carbon dioxide (CO 2 ) concentration and the temperature dynamics. The resulting expressions are convex in the zonal mass flow rates and zonal temperatures. Guided by the steady state solutions for meeting the thermal comfort constraints, we develop two control policies for improving the energy efficiency of building HVAC systems while jointly satisfying indoor temperature and IAQ constraints. We compare the performance of our proposed approaches with those of multiple baseline approaches which implement separate regimes for controlling zonal temperature and IAQ for a typical work-day in a multi-zone campus building. We have evaluated the performance of our proposed approaches under varying levels of flexibility in zonal temperatures. We have shown that zonal temperature flexibility can result in energy savings up to 32% (for the same control strategies) as compared to the case where no such flexibility is permitted. Our proposed approaches were seen to offer potential savings of nearly 29% compared to the baseline.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Adopting Energy Efficiency in Connected Homes

This presentation on connected homes was presented at the 11th Rocky Mountain Utility Efficiency Exchange on September 28, 2017. The discussion covered the integration of energy efficiency measures and practices with Internet of Things (IoT) awareness and adoption of smart technologies and services via WiFi/ Bluetooth enabled home and office equipment. The presentation also describes the benefits to the home and business and benefits/challenges for the utility/implementer.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Energy-Efficient and Resilient Infrastructure: Simulation, Validation, and Installation

Advanced, high-performance computing at the National Renewable Energy Laboratory (NREL) has enabled access to vast data resources with cutting-edge software techniques to understand, design, plan for, and maintain energy-efficient and resilient infrastructure. We have focused on cities and airports, but the technology we have developed will easily translate to seaports, inland ports, military installations, or other complex and large-scale energy-intensive systems. We can digitally simulate and explore current and future scenarios to make datadriven decisions for optimizing advanced energy systems, transportation and building operations, infrastructure planning and expansion, and battery storage to guide short- and long-term investments, electrification strategies, and integration of new technologies.

Athena↗

Hamilton: Flexible, Open Source $10 Wireless Sensor System for Energy Efficient Building Operation

Sensors for improving building performance are rapidly populating the market, driven in part by the drive to reduce greenhouse gas emissions resulting from energy production as well as improve the interior environment for healthy and more productive spaces. UC Berkeley has led wireless sensor development over the past 25 years (e.g., Telos mote), with the Hamilton (named after Alexander Hamilton on the US $10 bill) as the most recent. The Hamilton sensor was designed as a low-cost high-performance sensor that is modular and interoperable. The objective of the Hamilton project was to create, evaluate and establish the technological foundations for secure and easy to deploy building energy efficiency applications utilizing pervasive, low-cost wireless sensors integrated with traditional Building Management Systems (BMS), consumer-sector building components, and powerful data analytics. The project included iterative hardware design, incorporating a high-performance database (BTrDb, http://btrdb.io/), creating and iterating the development of secure data middleware (BOSSwave, WAVE/WAVEMQ), working with and pushing the development of an open-source tiny operating system RiotOS, and implementing and improving protocols such as Thread/OpenThread and TCP/IP. The hardware benefited from careful design to drive down the cost; the design included a System-on-a-Chip (SoC), chip antenna, single crystal and five passive components. Careful design of the operating system created a low-power design to enable a long life with small batteries. The hardware included several sensors: temperature, radiant temperature, relative humidity, magnetometer, accelerometer, and light, with an optional occupancy (Passive InfraRed) sensor. The project was the basis of several applications, both internal to the research team and other researchers and professionals at other institutions. Several applications used the sensor hardware as the basis for other complex devices. Other applications used the sensors to improve building performance through interoperating with the building Heating Ventilation and Air-Conditioning (HVAC) system, such as using occupancy and/or distributed temperature sensing to reduce HVAC zone energy while still providing thermal comfort and to reduce peak loads in small commercial buildings. We demonstrated cloud-based energy analytics, implemented a schedule and a Model Predictive Controller in a small commercial building to optimize HVAC energy, occupancy and electricity price. Initial integration of these technological innovations was performed through the creation of execution containers containing the WAVE agent and various driver, proxy, or building system function logic. The research added to the understanding of efficient sensor hardware, secure middleware, time-series data management (high performance database), efficient communication protocols, and interoperating with applications and building systems. The project showed the technical effectiveness and economic feasibility of creating a low-cost, modular, and easy-to-deploy sensor. Through conversations with multiple end users, the research team discovered that many customers wanted data management and services in addition to the sensors. HamiltonIOT developed packages of sensors, border router, and data services to provide a seamless “plug-and-play” sensor deployment. Some customers were willing to pay for higher quality sensors (such as light); some customers wanted a robust enclosure (waterproof).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Refrigeration Playbook: Natural Refrigerants; Selecting and Designing Energy-Efficient Commercial Refrigeration Systems That Use Low Global Warming Potential Refrigerants

This report provides guidance for selecting and designing energy efficient commercial refrigeration systems using low global warming potential refrigerants. Refrigeration systems are generally the largest energy end use in a supermarket type building, often accounting for more than half of a building's energy consumption.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

IoT-Based Comfort Control and Fault Diagnostics System for Energy-Efficient Homes

This project studies an Internet of Things (IoT)-based comfort control and fault diagnostics system (referred as iComfort in this report) for energy-efficient homes. The system delivers an occupant-comfort-oriented thermal environment adaptive to fault scenarios and achieves HVAC energy savings in a cost-effective and straightforward way. This smart iComfort home system consists of the following key features. 1) Cost-effectiveness and scalability of the entire hardware and software system: The system includes low-cost temperature, humidity, and airflow sensors, and a Raspberry Pi-based local hub that interfaces with the cloud and IoT-enabled devices. The cost is low, not only for sensors, but also the costs associated with sensor installation, system setup and commissioning, data communication and storage, and data analytics (e.g., the development of automated fault detection and diagnosis (AFDD), as well as adaptive control strategies that are both computationally efficient and practical to implement). 2) Energy performance and user satisfaction: The system delivers user satisfaction and energy savings. This includes a) ease of use, b) optimal occupant thermal comfort, and c) accurate system feedback (e.g., low false alarm of AFDD strategies). 3) Favorable demonstrated prototype performance: The prototype tested at the Pacific Northwest National Laboratory (PNNL) Lab Homes demonstrates the accuracy of fault detections and diagnoses and shows thermal comfort improvement and energy savings through adaptive and optimal HVAC operations.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Comparison of full-scale engine and subscale model performance of a mixed flow exhaust system for an energy efficient engine (E3) propulsion system

A full scale engine test of the NASA/General Electric Company (GE) Energy Efficient Engine (E3) was conducted to demonstrate the E3 engine concept and evaluate its performance. The test program, performed at the GE outdoor engine test facilities in Peebles, OH, included a detailed evaluation of the total pressure and temperature profiles at the exit of the mixed flow exhaust system to determine its mixing effectiveness. Subscale model tests of the same mixed flow exhaust system had been previously conducted at FluiDyne Engineering Corporation in Minneapolis, Minnesota as part of the GE E3 mixer aerodynamic technology development program. The scale model and full scale engine nozzle exit survey data and the calculated mixing effectiveness are compared and discussed. Results indicate the full scale engine mixing effectiveness to be five percent higher than the scale model as a result of a geometric difference and higher turbulence levels in the engne exhaust flowfield.

Kuchar, A. P.↗

Energy efficient engine. Low pressure turbine test hardware detailed design report

The low pressure turbine for the energy efficient engine is a five-stage configuration with moderate aerodynamic loading incorporating advanced features of decambered airfoils and extended blade overlaps at platforms and shrouds. Mechanical integrity of 18,000 hours on flowpath components and 36,000 hours on all other components is achieved along with no aeromechanical instabilities within the steady-state operating range. Selection of a large number (156) of stage 4 blades, together with an increased stage 4 vane-to-blade gap, assists in achieving FAR 36 acoustic goals. Active clearance control (ACC) of gaps at blade tips and interstage seals is achieved by fan air cooling judiciously applied at responsive locations on the casing. This ACC system is a major improvement in preventing deterioration of the 0.0381 cm (0.015 in.) clearances required to meet the integrated-core/low-spool turbine efficiency goal of 91.1% and the light propulsion system efficiency goal of 91.7%.

Cherry, D. G.↗

Energy Efficiency and Indoor Environmental Quality Assessment Guide

This report provides thorough guidance when preparing for an energy and indoor environmental quality (IEQ) assessment. It includes step-by-step instructions, detailed insights, and practical examples for the various phases of an energy and IEQ assessment. IEQ encompasses indoor building conditions—such as air quality, thermal comfort, acoustics, and lighting— and is a growing field of interest among a diverse range of stakeholders (e.g., building owners and managers) due to the effects it has on occupant health and productivity. IEQ improvement strategies often provide overlapping opportunities for increasing building energy efficiency, creating a win-win situation for building operations.

Esaki-Kua, Lauren↗

Novel Electrowinning Reactor for the Energy-Efficient, Low- Cost Production of Rare Earth Metals

This project developed a novel neodymium (Nd) electrowinning reactor for energy-efficient electrowinning of Nd metal. Throughout this project we have developed an alternative chloride based molten salt electrolysis process. Our process lowers the specific electrical energy consumption compared to the state of the art, while producing reusable chlorine gas and eliminating direct CO2 and PFC emissions. Facilities required for implementing the project were setup and designs were finalized, and a standard operating procedure for safe operation of high temperature electrolysis cells was written. The electrowinning reactor was designed and constructed. Electrolysis experiments confirmed the ability to reproducibly electrowin Nd metal on a Mo cathode. The current efficiency for Nd electrowinning was measured as a function of applied current density in the presence of the separator. Successful electrowinning of Nd sponge at high current densities (200 mA/cm2 and above) at a current efficiency >80% was demonstrated using multiple techniques. Stable Nd electrowinning up to 10h at 250 mA/cm2 was demonstrated. All of these design advancements were used to develop a techno-economic and life cycle assessment model that demonstrated that our process could be operated at cost of less than $0.20/kg-Nd (~30% lower compared to state of the art when comparing electrolysis energy cost) with a >20% total reduction in global warming potential compared to the state of the art while generating no direct CO2 or perfluorocarbon emissions.

42 ENGINEERING↗

ENERGY EFFICIENCY UPGRADES FOR SANITATION FACILITIES IN SELAWIK, AK FINAL REPORT

The Native Village of Selawik is a federally recognized Alaskan tribe, located at the mouth of the Selawik River, about 90 miles east of Kotzebue in northwest Alaska. Due to the community’s rural location and cold climate, it is common for electric rates to be four times higher than the cost urban residents pay. These high energy costs were the driving factor for Selawik pursuing funding from the Department of Energy in order to achieve significant energy cost savings. The main objective of the project was to improve the overall energy efficiency of the water treatment/distribution and sewer collection systems in Selawik by implementing the retrofit measures identified in a previously conducted utility energy audit. One purpose for the proposed improvements was to enable the community to realize significant savings associated with the cost of energy. Another purpose of the upgrades was to repair the vacuum sewer system on the west side of Selawik to prevent future freeze-up problems during winter months.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Leech Lake Band of Ojibwe Investment Grade Audit for Service Performance Contracting: First Steps Toward Developing Renewable Energy and Energy Efficiency on Tribal Lands

The Leech Lake Band of Ojibwe (Band) performed an investment grade audit (IGA) to identify energy conservation measures to increase energy efficiency in 22 of the Leech Lake Band of Ojibwe’s worst performing government buildings. With this IGA the Band identified energy control measures to reduce our energy use by 2,728,278 kW/year. The funding also provided for the drafting and printing of the Band’s Sustainability Energy Portfolio.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Nano-based PCMs for building energy efficiency

Thermal storage using phase change materials (PCMs) is seen as a viable method for improving the energy efficiency of buildings. PCMs have been used in building applications in various forms PCM slurries in heat exchangers, macro- or microencapsulated PCMs in building envelopes, bulk PCM for modulating photovoltaic temperatures, etc. In the last decade a new class of PCMs, called nano-enhanced PCM (or nanoPCM), has been extensively investigated with the goal of improving the heat transfer and thermal storage properties of PCMs. NanoPCMs can primarily be categorized as nano-encapsulated PCMs and nanoparticle-PCM composites. The former are nano-sized capsules in which the PCM forms the core and is surrounded by a high-conductivity membrane or shell. The latter consist of PCM supported within nanostructures or nanoparticles dispersed in PCMs. This article reviews the current state of nanoPCM synthesis and characterization of their heat transfer and thermal storage properties. Further, a critical review of nanoPCM applications and their potential energy benefits is performed. Nano-enhanced PCMs exhibit higher thermal conductivities than regular PCM. However, whether the higher conductivity is desirable in all applications and if the property enhancements are worth the cost and effort needed to create nanoPCMs are questions that still need to be answered.

nano-encapsulated PCM↗

Modeling the Interaction Between Energy Efficiency and Demand Response on Regional Grid Scales: Preprint

With increasing penetration of intermittent renewable generation at grid and distributed scales, flexible building loads can provide significant system value and support the evolving needs of the grid. The growing value of load flexibility may complicate the traditional separation between energy efficiency (EE) and demand response (DR). EE measures may compete in some cases with a building’s DR capabilities but complement one another in other cases. EE can also increase or decrease the need for DR at the system level and change the availability of DR to meet system needs. In this study we present a bottom-up approach to modeling interactive effects between EE and DR in buildings within two regions of the US electricity grid. From a library of building simulation models for different buildings and climates, we synthesize system-level demand profiles and the impacts of potential future EE portfolios. Coupling the underlying building models with a database of DR-enabling technologies, we then compute the quantity of DR that can be delivered in each scenario. The results show that EE and DR interactions are largely driven by the timing of EE savings that are measure-specific and the coincidence with system peak demand that is region-specific. We also find that perspective of the impacts matters – for instance that some EE measures reduce the system need for DR but also reduce the DR potential. Our results imply that utility EE and DR programs developed without considering interactive effects may lead to increased grid-management challenges over the long term.

buildings↗

A Membrane Contactor Enabling Energy-Efficient CO 2 Capture from Point Sources with Deep Eutectic Solvents

We demonstrate a scalable and energy-efficient hollow fiber membrane contactor (HFMC)-based process using a green solvent for CO 2 capture. This process uses a deep eutectic solvent (DES) in an HFMC to provide close interfacial interactions and contact between the DES and CO 2 . This approach overcomes disadvantages associated with direct absorption in DES and could potentially be applied to a variety of solvent-based CO 2 capture methods. Commercial low-cost polymer hollow fiber membranes (e.g., microporous polypropylene) were evaluated for CO 2 capture with reline, a prototypical DES. Single-gas measurements showed that the DES-based polypropylene HFMC can capture and separate CO 2 while rejecting N2. From a mixed gas containing 50 mol % N 2 and 50 mol % CO ν , the DES-based HFMC separated CO 2 with a purity of 96.9 mol %. The effect of several process parameters including solvent flow rate, pressure, and temperature on the CO 2 separation performance was studied. The flux of the recovered CO 2 was 67.43 mmole/m 2 /h at a feed pressure of 4 bar. In situ Fourier transform infrared (FTIR) measurements combined with density functional theory (DFT)-based molecular dynamics simulations revealed that reline absorbs CO 2 by physical absorption without forming a new chemical compound, and CO 2 separation by reline occurs via the pressure swing mechanism. This research provides fundamental insights about physical solvent-based separation processes and a pathway toward practical deployment.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗