Light pollution is the intrusion of unwanted or unneeded artificial light into a man-made or natural environment. A variety of somewhat separate phenomena comprise the...
Photovoltaic energy valuation modelLast Updated on 2012-02-01 00:00:00
Photovoltaic Energy Valuation Model
Sandia National Laboratories in collaboration with Solar Power Electric™ has developed PV ValueTM, an electronic form to standardize appraisals of homes and businesses outfitted with photovoltaic (PV) installations. While the tool is licensed for solar PV installations, it could be used for other large green features in a home that generate income, such as wind turbines. The spreadsheet, user manual and webinar explaining the tool are available for download at http://pv.sandia.gov/pvvalue.
The tool has been designed to be used by real estate appraisers, mortgage underwriters, credit analysts, real property assessors, insurance claims adjusters and PV industry sales staff. For appraisers, the inputs specific to PV in the Residential Green and Energy Efficient Addendum can be used as inputs to PV Value™.
Valuing a PV... More »
Phosphor-Based White LEDs: Mixed Blessings?Last Updated on 2012-01-26 00:00:00
Light-emitting diodes use less energy and last longer than even compact fluorescent lights.This article, written by Angela Spivey*, appeared first in Environmental Health Perspectives—the peer-reviewed, open access journal of the National Institute of Environmental Health Sciences.
The article is a verbatim version of the original and is not available for edits or additions by Encyclopedia of Earth editors or authors. Companion articles on the same topic that are editable may exist within the Encyclopedia of Earth.
The Mixed Blessing of Phosphor-Based White LEDs
Light-emitting diodes (LEDs), which use less energy and last longer than even compact fluorescent lights,1 are predicted to become the leading lighting technology in the United States as incandescent bulbs are phased out.2 But Abraham Haim, director of the Israeli Center for Interdisciplinary Studies... More »
Dark side of insulationLast Updated on 2011-02-09 00:00:00Building insulation has become a modish activity in the western world since the 1980s. Considerable benefits can accrue in energy conservation, occupant comfort and reduction of noise pollution from external sources. A dark side of insulation arises, however, from its trapping of radon gas, cigarette smoke, household sprays and other toxins within the enhanced imperviousness of the building skin. Furthermore, insulation can promote the entrapment of moisture, that in turn may increase the formation of molds and mildews, some of which contain toxic species.
Compounding the problem of trapping indoor air pollutants, some insulation techniques employ fibers and chemicals that themselves have adverse human health effects including toxicity risks. While use of asbestos has been a long known risk, there are a host of recently developed chemical substances and fibers that pose entirely... More »
Light pollutionLast Updated on 2010-08-05 00:00:00
Light pollution is the intrusion of unwanted or unneeded artificial light into a man-made or natural environment. A variety of somewhat separate phenomena comprise the overall issue of pollution due to excess artificial light: Over-illumination, glare, light trespass and skyglow. Adverse impacts of light pollution include human annoyance, interference with ecosystems, human health effects, interference with astronomical observation and wasteful consumption of energy. Sources of interior light pollution consist chiefly of unnecessarily intense lighting; principal sources of outdoor light pollution include street lighting, poorly designed stadium and recreational lighting, gratuitous building uplighting and unnecessary use of office interior lighting intruding into the night sky.
Local governments have begun to regulate certain aspects of light pollution; in particular,... More »
Smart gridLast Updated on 2009-10-07 03:40:12The term Smart Grid refers to an electricity distribution system that allows for flow of information from a customer’s meter in two directions: both inside the house to thermostats and appliances and other devices, and back to the utility. This could allow appliances to be turned off during periods of high electrical demand and cost, and give customers real-time information on constantly changing electric rates. Efforts are being made in both industry and government to modernize electric distribution to improve communications between utilities and the ultimate consumer. The goal is to use advanced, information-based technologies to increase power grid efficiency, reliability, and flexibility, and reduce the rate at which additional electric utility infrastructure needs to be built.
Both regulatory and technological barriers have limited the implementation of Smart Grid... More »
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