The COVID-19 pandemic has created an urgent need to utilize existing and develop new intervention technologies for SARS-CoV-2 inactivation on surfaces and in the air. Ultraviolet (UV) technology has been shown to be an effective antimicrobial intervention. Here a study was conducted to determine the efficacy of commercially available UV and blue light-based devices for inactivating HCoV-229E, a surrogate of SARS-CoV-2. The results indicate that two UV devices designed for surface disinfection, with doses of 8.07 mu J/cm(2) for the 254 nm device and 20.61 mu J/cm(2) for the 275 nm device, were efficient in inactivating 4.94 logs of surface inoculated HCoV-229E. Additionally, a 222 nm UV device with intended ceiling-based operation was effective in inactivating 1.7 logs of the virus inoculated on surface, with a dose of 6 mJ/cm(2). A ceiling-based device designed to emit blue light at 405 nm was found to produce 89% reduction in HCoV-229E inoculated on a surface for a dose of 78 J/cm(2). Finally, the UV based 222 nm device was found to produce a 90% reduction in the concentration of airborne HCoV-229E, at a 55 mu J/cm(2) dose. These results are indicative of the great potential of using UV based technology for the control of SARS-CoV-2.Implications: An important avenue of arresting COVID-19 and future pandemics caused by infectious pathogens is through environmental disinfection. To this effect, the study presented here evaluates commercially available UV and blue light based antimicrobial devices for their ability to kill the human coronavirus HCoV-229E, a surrogate of SARS-CoV-2, on surfaces and in air. The results indicate that two handheld UV devices produced complete inactivation of surface viral inoculum and a UVC ceiling based device produced 1 log reduction in HCoV-229E in air. These results imply the efficacy of UV technology as an antimicrobial tool, especially for rapid disinfection of indoor air.

With the advent of distributed energy resources (DERs) and proliferation of single-phase consumer loads based on power electronics, the problem of voltage and current distortion due to frequencies in the range 2 to 150 kHz (also known as supraharmonics) is becoming more and more common. In order to assess the impact of such grid changes on end use load in the United States (US), a multiple year project was launched by the Electric Power Research Institute (EPRI). This paper presents select results from this project, involving LED based lighting commonly sold in the US consumer market. Although LED lamps themselves have been shown to be sources of supraharmonics emission, the results in this paper show that under certain conditions, the presence of supraharmonics in applied voltage can lead to the production of visible flicker from such lamps. Furthermore, during testing, audible noise was also observed to be emanating from some of the lamps. The results confirm and agree with the results of similar tests conducted in Europe. In contrast to previous studies however, a light flickermeter specified in IEC 61457 was used in these tests so that the results could be quantified in a format familiar to most Power Quality engineers. In addition to informing knowledge of supraharmonics emission at the utility level, the results shown in this paper are intended to guide and inform active discussion on the subject of supraharmonics and flicker in IEEE standards committees, where two active PARs on these subjects are currently under discussion and deliberation.

Solar-based electrical power depends upon arrays of solar cells to produce voltage—direct current (DC) voltage. To operate equipment requiring alternating current (AC), or to connect to a utility’s distribution system, photovoltaic (PV) systems depend upon power electronic converters—devices that chop DC voltage into an approximation of an AC sine wave. Such devices, called inverters, operate at speeds that may produce radio frequency (RF) emissions (also known as electromagnetic interference, or EMI) over a broad range of frequencies. Photovoltaic installations may cover large swathes of territory. How may these emissions be identified, located, and monitored effectively and how may the effectiveness of any mitigation efforts at specific locations be assessed at a future date at the same specific locations? The Autonomous Mobile Measurement Platform (AMMP), a mobile measuring platform first developed to take repeatable measurements of multiple, interior building conditions (light, temperature, air quality, EMI, and others), was adapted for measuring EMI in the outdoor environment, such as at a PV installation. The focus of this paper concerns the application of the AMMP to survey, measure, and record for later analysis EMI conditions at specific points within a PV site— and the repeatable measurement of EMI at those same points in the future.

Modern dimmers are designed to work effectively with many light emitting diode (LED) lamps. Yet, testing has found that residential LED lamp dimming performance varies dramatically based on the dimmer that the lamp is paired with. Data presented in this paper shows that the same lamp can display up to a 25% difference in performance when dimmed with different dimmers. For example, an LED lamp rated for 800 lumens, when paired with an LED compatible dimmer, can experience a reduction in light output that would make the lamp more equivalent to a 40 W incandescent than a 60 W incandescent. These variances can impact overall system performance and consumer experience. Dimming performance has not been a reported aspect for efficiency ratings in the past, but given the impact a dimmer has on a lamp, more thought and effort needs to be put into standardizing dimmer compatibility and providing the consumer with an expectation of performance. This paper delivers information to utility and industry participants on the importance of assuring compatibility of paired lamps and dimmers. Proper performance increases the likelihood of improved consumer experience and results in higher energy efficiency program participation. Background of Residential Lighting Lighting is estimated to consume about 11% of total electricity in the United States (EIA, 2015). Residential lighting is estimated to be about 14% of the annual residential electricity consumption in the United States (EIA, 2015). A range of residential lighting technologies are included in these consumption numbers, but primarily, incandescent, halogen, compact fluorescent lamp (CFL), fluorescent, and LED are the notable residential lighting technologies. These technologies may be utilized in a variety of fixture types around the home such as table lamps, floor lamps, pendants, recessed cans, ceiling fixtures, chandeliers, and decorative fixtures. The majority of these residential fixtures contain sockets for A-type lamps1 and directional lamps.2 1 A-type lamps refer to the shape and size of the bulb. Common A-type shapes include A19 and A21. The number in A19 refers to the width of the lamp in eighths of an inch (A19 = 2 and 3/8 inches). 2 Typical directional lamps include BR30, R20, PAR30, and PAR38. PAR stands for parabolic aluminized reflector. The number following the letters indicates the width of the lamp in eighths of an inch. 1-1 ©2016 ACEEE Summer Study on Energy Efficiency in Buildings Figure 1. Example of an A-type lamp (left) and a directional lamp (right) The large amount of electricity annually consumed by residential lighting means understanding the true performance of residential lighting is vital to assure consumer stratification with lighting technologies and to help energy efficiency programs be successful. As efforts to reduce energy consumption have increased, LED manufacturers have improved and expanded the variety of LED products to provide efficient replacements for virtually all residential lamp types. Though LED lamps are widely discussed and touted, as of 2014, LED Atype lamps had only reached 2.4% of sockets in the U.S. across all sectors (DOE, 2015). Similarly, the market penetration of directional LED lamps is only 5.8% (DOE, 2015). Utility rebating programs have helped push these numbers to where they are, but these small percentages show that there is still a large, untapped energy savings potential within the residential lighting marketplace. In the past few years, LED residential market share numbers have been rising, but there are still many barriers to overcome before mass adoption. Hurdles routinely vary by the individual but can also vary from by region due to state and local regulations and public perception. Some states have raised awareness regarding limited energy availability in the region while other states have little need of reducing energy consumption. While price is generally the largest barrier (DOE, 2015), other barriers to residential LED adoption may be: • lack of understanding regarding total value of product (Osram, 2015) • complexity of choices (too many features/options to choose from) • negative experiences with other energy efficient products • unattractive shape or color temperature of the product • lack of dimming or poor dimming quality Some of these barriers may stem from lack of education regarding LED technology, while other barriers may stem from issues with other energy efficient products. With unfamiliar choices to consider – including color temperature, dimmability, color rendering index (CRI), lifetime, and shape the customer can easily feel overwhelmed and revert to selecting, lighting products they are more familiar with. Utility energy efficiency programs have proved to be a valuable resource for customers to help make informed decisions and to remove some of the barriers such as high cost and product unfamiliarity. Whatever the barrier, LED adoption still remains relatively low throughout the lighting marketplace. The following sections will focus on defining and addressing one of these barriers – dimming incompatibility. 1-2 ©2016 ACEEE Summer Study on Energy Efficiency in Buildings 1©2016 ACEEE Summer Study on Energy Efficiency in Buildings Dimming, Dimmers, and Dimmability

Induction cooking is often considered one of the most efficient cooking technologies. With this technology, up to 90% of the energy consumed is transferred to the food, compared to about 74% for traditional electric systems and 40% for gas. This technology has become popular in Europe, but its adoption in the US has been less enthusiastic. Several market barriers exist for this technology, including high first cost, the requirement of magnetic cookware, and lower perceived reliability. This paper presents findings from a technical assessment of induction cooking performed by the Electric Power Research Institute (EPRI) for the California Energy Commission (CEC). This assessment evaluated the cooking efficiency of induction technology and estimated its energy savings potential. Total cost of ownership is considered, as well as market barriers and non-energy benefits offered by induction cooking technology. The findings of this study demonstrate that induction cooking is not always more efficient that conventional electric (resistive) technology. The energy savings potential of induction cooking is found to be greatest when used with small cookware. The impact of these findings on standard test procedures is discussed, and recommendations for improvement are suggested. Finally, a prototype cooker design is presented, with a discussion of the limitations of current designs that prevents their operation with non-magnetic cookware.

With an expanding population and finite natural resources, it is critical to develop and implement energy-saving solutions that meet the needs of society without impacting future sustainability. LEED (Leadership in Energy and Environmental Design) certification is an effort to promote the selection and use of high-efficiency products. Within LEED, the use of energy-efficient lighting and daylighting (the use of natural sunlight for indoor lighting applications) is a focus.Daylighting is an area of significant research within the lighting industry and one of the largest areas of interest for those pursuing LEED certification. If designed and implemented correctly, daylighting can deliver environmentally neutral lighting to interior spaces. Once a daylighting system is installed, there is no ongoing impact as there is no pollution, no sources to maintain, no energy drawn, and little fixture maintenance required over the life of the product.There are a variety of daylighting designs in the marketplace, but limited information on how or where they are best utilized. If not properly utilized daylighting can result in ineffective lighting and unsatisfied consumers. Ineffective daylighting designs may cause users to revert back to more environmentally taxing lighting solutions. Additionally, ineffective implementation of daylighting can create a negative view of efficient lighting.This paper evaluates the design and implementation of various daylighting systems. It discusses three primary designs: skylights, solar concentrators, and tubular daylighting devices. Each design has unique uses and limitations. This paper is a brief guide to assist in the understanding and selection of daylighting technologies. (C) 2014 Elsevier Ltd. All rights reserved.

More than 1.2 billion people around the world live without electricity. The traditional utility approach to providing electricity using central generation, transmission and distribution is expensive. The World Bank estimates that it will take a trillion dollars through 2030 to solve this energy poverty. There is no economic model that will support this level of investment. DC Micro Grids are a cost effective way to provide the basic functions of electricity at a fraction of the cost of traditional electric delivery. This paper describes a scalable DC micro-grid. It is designed to be deployed in an individual residence/building. These buildings can then be interconnected into a self-sufficient larger DC grid. Long term, this larger DC grid holds the potential of being connected to existing utilities distribution systems. It includes renewable generation and energy storage assets which can provide sufficient electricity to power LED Lighting, cell phone charging, radio, TV, portable computers, water pumping and cooking. The DC micro-grid architecture, operation, performance and limitations are currently described and quantified. System cost is compared to traditional electric power delivery models in undeveloped regions.

The key objective of the work presented in this paper is to gain improved and updated understanding of the flicker performance of the latest lighting technologies. The work presented in this paper summarizes the detailed testing that has been performed to characterize the response of modern lighting to voltage fluctuations in the supply. The test plan was devised to capture the flicker response over a broad frequency range from 5 to 25 Hz. The modulation signal parameters were also varied to allow the study of the impact of amplitude and wave shape. Then, the impact of the operation of dimmers on the flicker performance of dimmable lighting technologies was evaluated. Finally, the impacts of excessive voltage fluctuations on other sensitive low voltage (LV) equipment were also investigated. The information in this paper should prove useful to decision makers in industry standard groups. (4 pages)

The increase in penetration and usage of harmonic rich loads can be expected to contribute to increased harmonic levels in distribution systems. The combination of the unbalanced nature of residential loads and usage of wye-wye service transformers means one can expect to see a continued increase in third harmonic levels in utility distribution systems. Also, the harmonic impact can be further exacerbated by the presence of reactive compensation in the form of capacitor banks on some feeders. This paper focuses on real-world problems related to excessive third harmonic levels in utility systems and the ways to address them. A real world case study that dealt with the failure of metal-halide lighting in a sports stadium at a public school due to excessive third harmonic levels in a utility feeder serving the load is presented. Several potential solutions to solve the problem were studied and the most suitable one was identified.