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At least 649 records · Page 36

How PV system ownership can impact the market value of residential homes

There are multiple ways for a homeowner to obtain the electricity generating and savings benefits offered by a photovoltaic (PV) system. These include purchasing a PV system through various financing mechanisms, or by leasing the PV system from a third party with multiple options that may include purchase, lease renewal or PV system removal. The different ownership options available to homeowners presents a challenge to appraisal and real estate professionals during a home sale or refinance in terms of how to develop a value that is reflective of the PV system s operational characteristics, local market conditions, and lender and underwriter requirements. This paper presents these many PV system ownership options with a discussion of what considerations an appraiser must make when developing the contributory value of a PV system to a residential property.

14 SOLAR ENERGY↗

Methods for Finding Legacy Wells in Residential and Commercial Areas

In 1919, the enthusiasm surrounding a short-lived gas play in Versailles Borough, Pennsylvania resulted in the drilling of many needless wells. The legacy of this activity exists today in the form of abandoned, unplugged gas wells that are a continuing source of fugitive methane in the midst of a residential and commercial area. Flammable concentrations of methane have been detected near building foundations, which have forced people from their homes and businesses until methane concentrations decreased. Despite mitigation efforts, methane problems persist and have caused some buildings to be permanently abandoned and demolished. This paper describes the use of magnetic and methane sensing methods by the National Energy Technology Laboratory (NETL) to locate abandoned gas wells in Versailles Borough where site access is limited and existing infrastructure can interfere. Here, wells are located between closely spaced houses and beneath buildings and parking lots. Wells are seldom visible, often because wellheads and internal casing strings have been removed, and external casing has been cut off below ground level. The magnetic survey of Versailles Borough identified 53 strong, monopole magnetic anomalies that are presumed to indicate the locations of steel-cased wells. This hypothesis was tested by excavating the location of one strong, monopole magnetic anomaly that was within an area of anomalous methane concentrations. The excavation uncovered an unplugged gas well that was within 0.2 m of the location of the maximum magnetic signal. Truck-mounted methane surveys of Versailles Borough detected numerous methane anomalies that were useful for narrowing search areas. Methane sources identified during truck-mounted surveys included strong methane sources such as sewers and methane mitigation vents. However, inconsistent wind direction and speed, especially between buildings, made locating weaker methane sources (such as leaking wells) difficult. Walking surveys with the methane detector mounted on a cart or wagon were more effective for detecting leaking wells because the instrument’s air inlet was near the ground where: 1) the methane concentration from subsurface sources (including wells) was a maximum, and 2) there was less displacement of methane anomalies from methane sources by air currents. The Versailles Borough survey found 15 methane anomalies that coincided with the location of well-type magnetic anomalies; the methane sources for these anomalies were assumed to be leaking wells. For abandoned well locations where the wellhead and all casing strings have been removed and there is no magnetic anomaly, leaking wellbores can sometimes be detected by methane surveys. Unlike magnetic anomalies, methane anomalies can be: 1) ephemeral, 2) significantly displaced from the well location, and 3) from non-well sources that cannot be discriminated without isotopic analysis. If methane surveys are used for well location, the air inlet to the instrument should be kept as close to the ground as possible to minimize the likelihood of detecting methane from distant, wind-blown sources.

54 ENVIRONMENTAL SCIENCES↗

Residential PV-Energy Storage Testing Collaboration with SunPower: Cooperative Research and Development Final Report, CRADA Number CRD-14-569

Residential scale energy storage devices have shown great promise to add value and improve the ability to integrate distributed and variable generation into the distribution grid. Battery energy storage systems combined with PV and advanced inverters can provide many services. These include extended backup power in case of grid failure, reductions in feeder and system level peak load, system level net load ramp reduction, grid management services both locally (e.g., voltage management) and bulk system (e.g., reserves) level, and improved grid reliability through grid voltage and frequency support. Even though the cost of the energy storage systems are decreasing, one of the main challenges related to the widespread deployment of energy storage, as found by the U.S. Department of Energy (DOE), is utility acceptance of storage technologies. Various interconnection challenges exist when connecting distributed PV-energy storage into the electrical distribution grid in terms of safety, reliability and stability of the electric power systems. Some of the urgent challenges, as seen by the manufacturers and installers are: safety of the battery cells and the packs, performance of the power conversion systems, effect of bidirectional power flow on existing utility equipment and qualification of solutions such as volt-ampere reactive (VAR) support and frequency regulation. Under this project, National Renewable Energy Laboratory (NREL) researchers will work with SunPower to address these challenges by research, testing and analysis at Energy System Integration Facility (ESIF) and energy storage testing laboratory at NREL. NREL's unique power hardware-in-the-loop (PHIL) capability will be utilized to evaluate system-level issues such as reverse power flow and VAR support (if available) for these PV-energy storage systems. Through the analysis of test results, the proposed project will demonstrate use of ESIF capabilities in a way that advances both the DOE and SunPower's goals of moving clean, renewable energy technologies onto the electrical grid.

14 SOLAR ENERGY↗

Measure Guideline: Ventilation Guidance for Residential High-Performance New Construction - Multifamily

The measure guideline provides ventilation guidance for residential high performance multifamily construction that incorporates the requirements of the ASHRAE 62.2 ventilation and indoor air quality standard. The measure guideline focus is on the decision criteria for weighing cost and performance of various ventilation systems. The measure guideline is intended for contractors, builders, developers, designers and building code officials. The guide may also be helpful to building owners wishing to learn more about ventilation strategies available for their buildings. The measure guideline includes specific design and installation instructions for the most cost effective and performance effective solutions for ventilation in multifamily units that satisfies the requirements of ASHRAE 62.2-2016.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Overview of Existing and Future Residential Use Cases for Connected Thermostats

This paper is intended to help inform future technology deployment opportunities for connected thermostats (CTs), based on investigation and review of the U.S. residential housing and CT markets, as well as existing, emerging, and future use cases for CT hardware and CT-generated data. The CT market has experienced tremendous growth over the last 5 years—both in terms of the number of units sold and the number of firms offering competing products—and can be characterized by its rapid pace of technological innovation. Despite many assuming CTs would become powerful tools for increasing comfort while saving energy, there remains a great deal of uncertainty about the actual energy and cost savings that are likely to be realized from deployment of CTs, particularly under different conditions.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Using Residential Solar PV Quote Data to Analyze the Relationship Between Installer Pricing and Firm Size

The vast majority of U.S. residential solar PV installers are small local-scale companies, however the industry is relatively concentrated in a few large national-scale installers. We develop a novel approach using solar PV quote data to study the price behavior of large solar PV installers in the United States. Through a paired differences approach, we find that large installer quotes are about higher, on average, than non-large installer quotes made to the same customer. The difference is statistically significant and robust after controlling for factors such as system size, equipment quality, and time effects. The results suggest that low prices are not the primary value proposition of large installer systems. We explore several hypotheses for this finding, including that large installers are able to exercise some market power and/or earn returns from reputations.

14 SOLAR ENERGY↗

Measure Guideline: Ventilation Guidance for Residential High-Performance New Construction - Multifamily

The measure guideline provides ventilation guidance for residential high performance multifamily construction that incorporates the requirements of the ASHRAE 62.2 ventilation and indoor air quality standard. The measure guideline focus is on the decision criteria for weighing cost and performance of various ventilation systems. The measure guideline is intended for contractors, builders, developers, designers and building code officials. The guide may also be helpful to building owners wishing to learn more about ventilation strategies available for their buildings. The measure guideline includes specific design and installation instructions for the most cost effective and performance effective solutions for ventilation in multifamily units that satisfies the requirements of ASHRAE 62.2-2016.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Overview of Existing and Future Residential Use Cases for Connected Thermostats

This paper is intended to help inform future technology deployment opportunities for connected thermostats (CTs), based on investigation and review of the U.S. residential housing and CT markets, as well as existing, emerging, and future use cases for CT hardware and CT-generated data. The CT market has experienced tremendous growth over the last five years — both in terms of the number of units sold and the number of firms offering competing products — and can be characterized by its rapid pace of technological innovation. Despite many assuming CTs would become powerful tools for increasing comfort while saving energy, there remains a great deal of uncertainty about the actual energy and cost savings that are likely to be realized from deployment of CTs, particularly under different conditions.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE Residential Energy Code Field Study - Pennsylvania

This project consisted of three distinct phases – all focused on residential one- and two-family dwellings and townhouses. Phase 1 included a baseline field study with inspections and performance testing to assess construction practices with respect to the energy code. PNNL used the data to perform EUI and savings potential analyses. Phase 2 consisted of training, education, and outreach to building industry professionals with content based on the findings from Phase 1. Phase 3 was a post-program field study using the same methodology as Phase 1 and was intended to measure the impact of Phase 2. During Phase 1 of the project, PSD collected data from 171 job sites across eastern Pennsylvania, a territory bounded by PECO, PPL, and Met-Ed electric distribution territories, to reach the required 63 “home equivalents” deemed necessary by PNNL for a representative sample. Based on subsequent analysis, four key items were identified as having significant savings potential from improvement in compliance, including duct leakage, above-grade wall insulation (specifically insulation installation quality), foundation insulation, and high-efficacy lighting. About half the total savings potential is from duct leakage, so that was the primary focus. The goal of Phase 2 was to improve upon these key compliance weaknesses through an intensive training, education, and outreach program. PSD dubbed this effort the Penn Energy Codes Program. For Phase 3, PSD obtained a new sample plan from PNNL, obtained permit data from sample municipalities, and made substitutions where necessary. PSD field staff visited 165 job sites to collect the required 504 key observations. PSD submitted all data collection sheets to PNNL for their analysis to determine if there was a measurable change due to Phase 2 activities.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Estimating Residential Appliance Lifetime for Energy Efficient Policy Analysis

Accurate knowledge of appliance lifetimes helps policy makers set effective energy efficiency policy. The cost-effectiveness of an appliance efficiency measure depends on the length of time consumers will use an appliance. National shipments projections depend on the rate of replacement in the installed appliance stock. Furthermore, early retirement programs need an accurate understanding of the remaining useful life in order to calculate lifetime savings and cost-effectiveness of a program. This paper uses a method for calculating lifetime of appliances based on the most recent data available on appliance shipments, total appliance stock, and the fraction of surviving appliances by age bins. An example of the calculation methodology is provided for residential gas boilers. This paper concludes by comparing the results to other available data on gas boiler lifetime.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Technology inventory: energy efficiency measures for residential, commercial, and industrial sectors in the United States

Energy efficiency is expected to continue to be one of main levers for governments to address the energy and climate crisis. While a diverse mix of energy efficiency programs has been regarded as an important part of governmental actions, an energy efficiency policy or program needs to identify and assess eligible savings measures, i.e., specific technologies or practices, for designing key features, e.g., target type, target stringency, covered load, and cost recovery. This report briefly discusses U.S. energy efficiency policies and programs, explores publicly available resources of energy efficiency measures for residential, commercial, and industrial sectors in the U.S., and describes how to compile key measures and characteristics into an integrated spreadsheet database. The database in the initial version offers, for more than 1,200 measures, efficiency or improvement potential, technical notes, costs at a given year, where applicable. Energy efficiency measures compiled here could play an important role in determining savings targets and target stringency under a potential energy efficiency policy such as an energy efficiency resource standard in Korea, and offer significant opportunities for energy efficiency improvement.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Residential HVAC Installation Practices: A Review of Research Findings

This report summarizes relevant findings from available literature and research that were evaluated to better quantify the potential benefits of improving current installation practices for heating, ventilation, and air conditioning (HVAC) equipment in existing homes (i.e., equipment replacements). Although some of the findings may be informative and applicable to the new construction market, this report focuses on analyses specific to the single-family residential HVAC replacement market. The research findings summarized in this report reveal that improving the installation of central heating and air conditioning systems has the potential to decrease operating and maintenance costs, decrease equipment purchase price, improve indoor air quality and overall indoor comfort, and reduce household energy consumption by mitigating a variety of common system performance issues.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Residential HVAC Installation Practices: A Review of Research Findings

This report summarizes relevant findings from available literature and research that were evaluated to better quantify the potential benefits of improving current installation practices for heating, ventilation, and air conditioning (HVAC) equipment in existing homes (i.e., equipment replacements). Although some of the findings may be informative and applicable to the new construction market, this report focuses on analyses specific to the single-family residential HVAC replacement market. The research findings summarized in this report reveal that improving the installation of central heating and air conditioning systems has the potential to decrease operating and maintenance costs, decrease equipment purchase price, improve indoor air quality and overall indoor comfort, and reduce household energy consumption by mitigating a variety of common system performance issues.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Characterize the Demand and Energy Characteristics of Residential Electric Vehicle Supply Equipment

The EV Project enrolled over 8,000 residential participants. These participants purchased or leased a Nissan Leaf or Chevrolet Volt. The EV Project provided and installed Blink Electric Vehicle Supply Equipment (EVSE), used to recharge their PEV, in exchange for their agreement to allow project analysts to evaluate data collected from charging their PEV at their residence and away from home. The power required to recharge a PEV can be a significant contributor to the electrical load a residence places on the electric grid. What insight can The EV Project data provide in characterizing this contribution in terms of power demand and energy consumption to assist electric utilities in PEV adoption planning?

33 ADVANCED PROPULSION SYSTEMS↗

Non-residential Electricity Prices: A Review of Data Sources and Estimation Methods

This paper presents a review of electricity price data sources and estimation methods for non-residential consumers, including a detailed empirical study of tariff-based prices collected as part of Lawrence Berkeley Lab's Tariff Analysis Project (TAP). We compare the TAP data to two other data sources: utility-level annual sales, revenues and consumer counts published by the Energy Information Administration (EIA), and the Typical Bills reports published by the Edison Electric Institute. A brief overview of the types of rate structures included in the TAP database illustrates the often complex relationship between the consumer's energy use and the costs they see on their electricity bills. We provide mathematical definitions of the different types of electricity price that are useful in cost-benefit analysis, construct estimation methods appropriate to each data set, compare the results, and evaluate the relative strengths and weaknesses of each approach. We also examine how price variation is driven by differences in season, region, industry business model, and variables characterizing consumer energy use. Tables of regional price estimates for each data source, based on 2015 data, are included in the Appendix to this paper.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Life Cycle Assessment of Future Photovoltaic Electricity Production from Residential-scale Systems Operated in Europe

The photovoltaics (PV) industry is growing rapidly to meet the increasing demand of green power. As the industry grows, the manufacturing processes and the material and energy efficiencies of PV cells and panels are improving. To assess the impacts of this trend, future scenarios of single-crystalline (single-Si, also known as mono-crystalline) silicon and cadmium-telluride (CdTe) PV systems installed on European residences were established. Assessment of the improvement potential of PV electricity-generating technologies such as single-Si and CdTe could be considered in long-term energy strategy decisions. This study aims to provide scenario-based information about the environmental per-formance of single-Si and CdTe PV modules produced and operated in the far future (2030 to 2050). The deployment application assessed considers European residential roofs. We made scenario-dependent projections of key parameters for single-Si and CdTe PV panels manufactured in 2050. The parameters included cell efficiency, module efficiency, wafer thickness, cutting losses, kerf losses, silver use, glass thickness and operational lifetime. This study combines developments for these parameters with projections of the environmental performance of electricity mixes in the main manufacturing countries/regions (European Union, China and the United States of America) and with projections of the environ-mental performance of basic material production (aluminium, copper, magnesium, nickel, pig iron, zinc, clinker and flat glass) in the far future. The three scenarios used in the assessment of future PV electricity were categorized into three classes: 'business as usual' (BAU), 'realistic improvement' (REAL) and 'optimistic improvement' (OPT). It estimates the current life cycle greenhouse gas emissions of single-Si PV electricity produced on the roofs of European residences to be approximately 80 grams CO2-equi-valent per kWh (g CO2-eq per kWh). Based on the projected changes to key parameters and the background system, life cycle greenhouse gas (GHG) emissions could be reduced to 65% (scenario BAU), 31% (scenario REAL) and 18% (scenario OPT) of that value in the far future. Results for other life cycle assessment (LCA) metrics are also assessed in this study such as: non-renewable cumulative energy demand, acidification potential, human toxicity potential, photochemical ozone creation potential, particulate matter formation potential, and land use. We calculated the total energy payback time (EPBT) and the non-renewable energy payback time (NREPBT) in the far future of single-crystalline silicon-based PV panels operated in Europe by dividing the estimate of non-renewable cumulative energy demand of PV electricity for the given scenario by the non-renewable cumulative energy demand of the scenario-dependent national and regional non-renewable residual electricity mixes. The study estimates the payback time could be reduced from 2.4 years today to 1.7, 1.2 and 1.2 years (scenarios BAU, REAL and OPT, respectively) in the far future, based on the assumptions and projections in the analysis. It finally estimates the current life cycle greenhouse gas emissions of CdTe PV electricity produced on the roofs of European residences to be approximately 30 g CO2-eq per kWh. Based on the projected changes to key parameters and the background system, life cycle GHG emissions could be reduced to 70% (scenario BAU), 44% (scenario REAL) and 32% (scenario OPT) of that value in the far future.

14 SOLAR ENERGY↗

Low-GWP Refrigerant Evaluation in AC Systems for High Ambient Temperature Applications – Acquire Nortek Residential AC/HP Units for Evaluation and Model the Units Using HPDM

For the upcoming refrigerant transition from HFCs to minorly flammable HFO refrigerants (A2L), refrigerant charge reduction is important to mitigate the fire hazard. Microchannel heat exchangers (MHXs) are a mature technology, which is effective in reducing system charge while maintaining similar heat transfer performance. MHXs will be applied more widely when the new refrigerants are used. Prior studies of the A2L HFO blends were mostly focused on fin-and-tube coils (FTC). An in-depth study for an air conditioner (AC)/heat pump (HP) system using all microchannel heat exchangers is still lacking. In FY19, a side-to-side comparison will be conducted between two residential split heat pumps, one using all FTCs and the other using all MHXs for drop-in investigation, to identify potential issues for future design. The two heat pumps have similar rated capacity, SEER, HSPF levels, similar fan, blower and compressor, but differ in heat exchangers. Both the HPs use two-stage compressors to facilitate investigating different refrigerant flow rates. We will drop-in HFO refrigerants (replacements for R-410A, e.g. R452B, R447B, R32, etc.). The experiments will reveal the potential of MHXs for charge reduction, and how the two systems using A2L refrigerants operate under standard SEER and HSPF rating conditions. The two units were donated by our partner, i.e. Nortek Global HVAC, an industry leader in making heat pumps using all MHXs as well as FTCs. The units were shipped to ORNL this week, and the product design data were also shared for modeling the two units using HPDM.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗