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At least 235 records · Page 13

Dynamic Analysis of a Six-Cable Parallel Robot for Automated Panelized Building Retrofits

Cable-Driven Parallel Robots (CDPRs) are highly suitable for automated panelized building retrofits, thanks to their compact footprint and high payload-to-weight ratio. A common CDPR configuration featuring eight cables, where the anchors form a rectangular prism in front of the building facade, offers a large wrench feasible workspace and good control versatility. However, installing upper anchor points requires additional support structures, such as towers or beams, increasing setup complexity and posing logistical challenges in construction settings. To mitigate these challenges, we propose a six-cable CDPR model specifically designed for automated panelized building retrofits. Although the feasible workspace is limited, our analysis shows that the proposed CDPR adequately covers the critical areas required for panel installation. To validate that the six-cable system can effectively transport the end effector to the desired installation pose, we calculated optimal trajectories based on a constrained dynamic model. The simulation results of the six-cable CDPR demonstrate promising potential for automated panelized building retrofits, effectively balancing simplicity, cost-effectiveness, and functionality.

Liu, Yifang [ORNL] (ORCID:0000000190817417)↗

High-Efficiency Retrofit Lessons for Retail from a SuperTarget: Preprint

The National Renewable Energy Laboratory partnered with Target under the Commercial Building Program to design and implement a retrofit of a SuperTarget in Thornton, CO. The result was a retrofit design that predicted 37% energy savings over ASHRAE Standard 90.1-2004, and 29% compared to existing (pre-retrofit) store consumption. The largest savings came from energy efficient lighting, energy efficient cooling systems, improved refrigeration, and better control of plug loads.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Roof and Attic Design Guidelines for new and retrofit Construction of Homes in Hot and Coild Climates

Some guidelines for improving the energy efficiency of roofs and attics are presented and are based on the research of the DOE Building Technology. The results of combined analytical and experimental studies were used to benchmark computer tools, which in turn, were used to simulate homes in hot and cold climates. Adding floor and roof insulation, above deck ventilation, radiant barriers, cool color shingle, metal or tile roofs, sealing the attic floor, sealing the duct system and sealing the attic were simulated to compute the cost of energy savings. Results are prioritized to help building owners make an informed economic decision when contemplating roof and attic retrofits. Sealing the attic floor is a top retrofit option. The sealed attic approach and a new prototype roof assembly an insulated and ventilated roof are good options for retrofit work but have paybacks ranging from 15 to 25 years. A new sealed attic concept was simulated and computations show its simple payback is about 10 to 12 years in hot and cold climates; its first cost is significantly reduced from that of a spray foam approach. For new construction the best option is to keep the ducts out of the attic, make sure the attic floor is sealed and add at least code level of insulation to the ceiling.

attic↗

Cold Climate and Retrofit Applications for Air-to-Air Heat Pumps

Air source heat pumps (ASHP) including air-to-air ASHPs are easily applied to buildings almost anywhere for new construction as well as retrofits or renovations. They are widespread in milder climate regions but their use in cold regions is hampered due to low heating efficiency and capacity at cold outdoor temperatures. Retrofitting air-to-air ASHPs to existing buildings is relatively easy if the building already has an air distribution system. For buildings without such systems alternative approaches are necessary. Examples are ductless, minisplit heat pumps or central heat pumps coupled to small diameter, high velocity (SDHV) air distribution systems. This article presents two subjects: 1) a summary of R&D investigations aimed at improving the cold weather performance of ASHPs, and 2) a brief discussion of building retrofit options using air-to-air ASHP systems.

Baxter, Van D↗

LCA of Carbon Capture Retrofit Using the “Petra Nova Style” Model - LCAXVIII

This work was presented at the American Center for Life Cycle Assessment (ACLCA) LCAXVIII Conference in Fort Collins, CO on September 26, 2018. This analysis compares the life cycle environmental impacts for an amine-based capture retrofit with an external co-gen source providing the utility inputs for capture compared to a more traditional retrofit in which the plant/unit output is de-rated with the utility inputs for operating the capture system coming directly from the plant. One of the major differences between the designs is that in the case of the external co-gen unit, the combustion emissions associated with operating the capture unit are not part of the flue gas stream that is directed to the capture unit. Another unique consideration in this analysis is the inclusion of the upstream natural gas life cycle in the boundaries of the co-gen retrofit.

Krynock, Michelle↗

Retrofit-ability: A supplementary metric to inform energy efficiency policies and programs

Building Energy Use Intensity (EUI) has been commonly used to facilitate policy makers and utilities to design energy efficacy programs and help building managers prioritize investment in building upgrades. Buildings with higher EUIs are usually chosen as better candidates for retrofit. Our study of nearly one hundred buildings in Seattle’s Building Tune Up Accelerator program and thousands of buildings in the Asset Score database reveals that EUI (after weather/location/use type normalization) alone is not the best indicator of a building’s potential to save energy, especially for those buildings in the mid-range (30-70 percentile EUI). In this paper, we introduce the concept of “retrofit-ability” — a building’s real potential to reduce its energy use cost-effectively — as a supplementary metric to inform energy efficiency policy and investment. Currently, such potential analyses are predicted for a building stock using prototypical building models or statistical data. However, typical buildings or general historical data may not sufficiently represent building configurations in a portfolio and predict their saving potentials. We utilized machine learning to investigate how key building characteristics (such as envelope attributes, HVAC type, location, use type, etc.) affect a building’s improvement potentials and developed a low-cost method to quantify such potentials for a portfolio of buildings. The supplementary perspective provided by “retrofit-ability” highlights which building assets correlate most with a building’s energy savings potential across region, building use type and more.

Wang, Na↗

Assessing the Performance, Application, and Cost of Retrofit Wall Systems for Residential Buildings

The Oak Ridge National Laboratory, Pacific Northwest National Laboratory, and the University of Minnesota have been conducting a three-year study of residential retrofit wall systems. The researchers have identified, tested, and verified the hygrothermal performance of 16 wall assemblies in retrofit applications. The approach to this study includes a comprehensive literature review, the involvement of an advisory group of thermal enclosure experts, smallscale experimental in situ testing of the wall assemblies at the University of Minnesota’s Cloquet Residential Research Facility, and energy and hygrothermal simulation of wall assemblies using EnergyPlus, THERM, and WUFI. Simulation and experimental results are then combined with an economic analysis to produce a techno-economic study of residential wall systems for deep energy retrofits.This presentation summarizes the findings of this research project and is intended to guide architects and designers on how to retrofit existing wall assemblies without creating durability issues.

Desjarlais, Andre Omer↗

Hygrothermal simulation of exterior retrofits in a cold climate

This work presents results from moisture modeling as part of a project undertaken by Pacific Northwest National Laboratory and its research partners, the University of Minnesota, and the Oak Ridge National Laboratory. The research goal is to identify exterior wall retrofit systems for cold climates that are low cost, energy efficient, and do not result in moisture durability problems. A base case wall was identified representing a typical wood frame construction, circa 1950. Retrofit options were selected based on input from industry, academia, and published work and seven options were constructed and installed at the University of Minnesota’s cold weather exposure facility in Cloquet, MN. Measurements were carried out during winter months and the data was used for model validation. Hygrothermal simulations were then carried out using WUFI (Version 6.4) in accordance with standard ANSI/ASRHAE 160-2016, Criteria for Moisture-Control Design Analysis in Buildings. Simulations were run out to three years and results show that the exterior retrofits improve thermal performance and do not negatively impact moisture durability of the existing wall.

Aldykiewicz Jr, Antonio↗

NETL's Carbon Capture Retrofit Databases

This PowerPoint presentation summarizes the recently published Carbon Capture Retrofit Databases and their supporting documents, such as user guides and studies used to inform cost and performance estimates. NETL publications used to develop slide contents include Cost of Capturing CO2 from Industrial Sources, 2022; Industrial CCRD, 2022; Eliminating the Derate of Carbon Capture Retrofits, 2023; PC CCRD, 2023; Cost and Performance of Retrofitting NGCC Units for Carbon Capture, 2023; and NGCC CCRD, 2023.

Hughes, Sydney↗

Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance, K-12 Schools (Book)

The U.S. Department of Energy developed the K-12 Advanced Energy Retrofit Guide to provide specific methodologies, information, and guidance to help energy managers and other stakeholders plan and execute energy efficiency improvements. We emphasize actionable information, practical methodologies, diverse case studies, and unbiased evaluation of the most promising retrofit measure for each building type. K-12 schools were selected as one of the highest priority building sectors, because schools affect the lives of most Americans. They also represent approximately 8% of the energy use and 10% of the floor area in commercial buildings.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Cascade Apartments - Deep Energy Multifamily Retrofit , Kent, Washington (Fact Sheet)

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Cascade Apartments: Deep Energy Multifamily Retrofit

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Cascade Apartments: Deep Energy Multifamily Retrofit

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions: 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Evaluation of Early Performance Results for Massachusetts Homes in the National Grid Pilot Deep Energy Retrofit Program

In 2009, National Grid started a DER pilot program that offered technical support and financial incentives to qualified Massachusetts homeowners who planned and successfully completed a retrofit that incorporated the performance requirements and goals of the National Grid DER measures package. This DER measures package, developed through collaboration with Building Science Corporation (BSC), includes specific thermal and airtightness goals for the enclosure components as well as health, safety, durability, and indoor air quality requirements. By providing measures that can be included with common renovation activities such as roof replacement, window replacement, re-siding, basement remediation, and remodeling, this DER measures package is expected to have widespread application for existing homes in the New England area. The post-retrofit performance and cost ranges provided by this research project can provide concrete input for homeowners who are considering a DER. Field test data available for air tightness measured using blower door test. House 1 - Address Belchertown, MA 01007, Notes: Energy Savings: 75%, Company: Clark House 2-1 and 2 - Address (1) Brownsberger, MA 02478 and (2) Belmont, MA 02478, Notes Energy Savings: 73%, Company: Brownsberger House 3 - Address Millbury, MA 01527, Notes Energy Savings: 31%, Company: Tweedly House 4 - Address Milton, MA 02186 Notes Energy Savings: 42%, Company: Koh House 5 - Address Quincy, MA 02169, Notes Energy Savings: 57%, Company: Hall House 6-1 and 2 - Address Arlington, MA 02476, Notes Energy Savings: 55%, Company: Venable-Hwang House 7 - Address Newton, MA 02459, Notes Energy Savings: 42%, Company: Lavine House 8-1, 2, and 3 - Address Jamaica Plain, MA 02130, Notes Energy Savings: 43%, Company: Buhs House 9 - Address Northampton, MA 01060, Notes Energy Savings: 49%, Company: Wick House 10 - Address Lancaster, MA 01523, Notes Energy Savings: 40%, Company: Habitat for Humanity of North Central Massachusetts House 11 - Address Brookline, MA 02445, Notes Energy Savings: 27%, Company: Aquiline House 12 - Address Westford, MA 01886, Notes Energy Savings: 30%, Company: Atkins House 13 - Address Gloucester, MA 01930, Notes Energy Savings: 35%, Company: Cunningham

airtightness↗

Existing Whole-House Solutions Case Study: Cascade Apartments - Deep Energy Multifamily Retrofit

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington, which resulted in annual energy cost savings of 22%, improved comfort and air quality for residents, and increased durability of the units. This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary Building America research questions: 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio of the retrofit package after considering utility window incentives and KCHA capital improvement funding.

BA-PIRC↗

Concentrating photovoltaic retrofit for existing parabolic trough solar collectors: Design, experiments, and levelized cost of electricity

Photovoltaics and concentrating solar thermal power are two ways for generating electricity from sunlight, albeit through different methods. Parabolic trough style powerplants represent 3.6 GW of electricity production, but many of these plants are aging and being replaced with photovoltaics. An alternative option that could be employed to leverage the sunk capital cost associated with the primary optics would be the design of a pure photovoltaic retrofit working within the existing plant architecture. Here, a secondary optical concentrator is designed to use the existing primary optics of a parabolic trough type solar thermal powerplant. The design is a v-shaped secondary concentrator resulting in a predicted concentration ratio on a 20 mm wide target of 94. The concentrating photovoltaic receiver for retrofit of an RP-3 based parabolic trough has been constructed using multi-junction concentrator photovoltaic cells and experimentally demonstrated here for the first time. Calculated performance of the cells based on cell specifications should result in 31% efficiency at 85 °C. On-sun efficiencies were measured at an average value of 21% with operational temperatures between 55 and 120 °C. Levelized cost of electricity calculations predict the system to have the potential to be below 7¢/kWh based on predicted efficiencies and 13¢/kWh based on the measured values at cell costs of $5/cm 2 .

14 SOLAR ENERGY↗

Derate Mitigation Options for Pulverized Coal Power Plant Carbon Capture Retrofits

Carbon capture and storage (CCS) technologies available in the near-term for pulverized coal-fueled power plants (i.e., post combustion solvent technologies) require substantial capital investment and result in marked decrease in electricity available for sale to the grid. The impact to overall plant economics can be mitigated for new plant designs (where the entire plant can be optimized around the CCS system). However, existing coal-fueled power plants were designed without the knowledge or intent to retrofit a CCS process, and it is simply not possible to re-engineer an existing plant in a manner that it could achieve the same performance as if it was originally designed and optimized for CCS technology. Pairing an auxiliary steam supply to the capture system is a technically feasible option to mitigate the derate resulting from diverting steam away from an existing steam turbine and continuing to run that turbine at steam flow rates and properties outside of the original design specifications. The results of this analysis strongly support the merits of meeting the steam and power requirements for a retrofitted post-combustion solvent based carbon dioxide (CO2) capture system with an auxiliary combined heat and power (CHP) plant rather than robbing the base plant (i.e., diverting steam from the existing steam cycle and electricity from sale to the grid).

01 COAL, LIGNITE, AND PEAT↗

Annual simulation of photovoltaic retrofits within existing parabolic trough concentrating solar powerplants

Solar power for electricity production comes from either photovoltaics or concentrating solar power plants. The former has seen rapid growth and expansion due to the rapid fall in global prices, while the latter has seen moderate growth due to ability to cheaply store thermal energy for later use. Hybridization, or combining photovoltaics with concentrating solar power represents a potential way for lowering cost while enabling long term storage. Over 5 GW of capacity exist worldwide using parabolic trough style technology for concentrating solar power which presents a unique option for optimization in the form of a photovoltaic retrofit. While it is possible to analyze the performance with detailed physics models, it is necessary to create a model that can handle simulating the plant level performance to fully understand the potential performance. Here, the first utility scale plant level model of a hybrid photovoltaic-concentrating solar power plant is developed. The model is applied to existing concentrating solar power plants around the world utilizing RP-3 mirrors without thermal energy storage to understand the impact on electricity production. Model results indicate that the photovoltaic retrofit can increase yearly electricity production by up to 30% for plants with solar multiples exceeding 1.5, and that increasing the fraction of solar energy reflected further increases the yield. The increased electrical production declines as the plant solar multiple is decreased. The minimum LCOE observed was $0.07/kWh for plants with larger solar multiple and fraction of solar energy reflected to the PV is 50% of the total aperture.

14 SOLAR ENERGY↗