Saving energy is always a good thing, and sometimes that means turning out the streetlights. As a result, pathways go unlit and this can be problematic for cyclists and pedestrians. Enter a new surface treatment that glows in the dark for free night time illumination known as Starpath.
Seeing that local city councils were increasingly shutting off park lights at night to save money, Pro-Teq developed Starpath to maintain public safety without the financial and environmental costs of overhead lighting. It’s a common problem; in the U.S. for instance, cities generally count streetlights as their first or second biggest energy drains.
But the glow-in-the-dark spray also comes with additional benefits: Its non-reflective surface doesn’t seem to contribute to light pollution, which not only inhibits views of the nighttime sky, but can have dire consequences for local wildlife due to the constant illumination.
Overhead street lighting does provide one important benefit to urban parks, however, and that’s the deterrence of crime. It’s not yet known if Starpath would provide enough light to do the same.
Read more here.
Thanks to Fraser
Four years ago Los Angeles decided to change its street lighting to LEDs and the results have come in and the savings are phenomenal. They have converted a little over half of all their street lights and are already saving $5,325,793 annually in lighting costs. It’s worth noting that LEDs use 80% less electricity than traditional lighting solutions while also providing better lighting for users of the street.
Hopefully the success that LA has seen will encourage other cities to make the switch to cheaper and more efficient lighting.
Maintenance savings are real, too: In 2008, pre-LED roll-out, Los Angeles logged 70,000 street light repair and maintenance events; in FY 2012, maintenance and repair events fell to 46,300. LEDs are longer lived than the incumbent units they replace (10-15 years versus 4-6 years), which means that maintenance should steadily decline as LED units are fully deployed. A remote monitoring system, installed with the LED fixtures, indentifies problems in real time.
LED fixtures also fail at a lesser rate than incumbent technologies. After 36 months of initial operation, for instance, high-intensity discharge (HID) fixtures in Los Angeles recorded an average failure rate of 10%; the average failure rate for LED fixtures, according to the latest figures, is 0.2% (189 of 98,000 installed). At full LED deployment, Los Angeles expects to save $2.5 million annually on maintenance costs.
Read more at Forbes.
In something that sounds close to magic, some researchers the American National Renewable Energy Laboratory have found a way to get solar cells to produce more energy with over an 100% quantum efficiency. Basically more energy is created than light that hits the cell. This is done by exploiting quantum mechanics to produce more energy from solar cells.
The external quantum efficiency for photocurrent, usually expressed as a percentage, is the number of electrons flowing per second in the external circuit of a solar cell divided by the number of photons per second of a specific energy (or wavelength) that enter the solar cell. None of the solar cells to date exhibit external photocurrent quantum efficiencies above 100 percent at any wavelength in the solar spectrum.
Quantum dots, by confining charge carriers within their tiny volumes, can harvest excess energy that otherwise would be lost as heat – and therefore greatly increase the efficiency of converting photons into usable free energy.
The researchers achieved the 114 percent external quantum efficiency with a layered cell consisting of antireflection-coated glass with a thin layer of a transparent conductor, a nanostructured zinc oxide layer, a quantum dot layer of lead selenide treated with ethanedithol and hydrazine, and a thin layer of gold for the top electrode.
In a 2006 publication, NREL scientists Mark Hanna and Arthur J. Nozik showed that ideal MEG in solar cells based on quantum dots could increase the theoretical thermodynamic power conversion efficiency of solar cells by about 35 percent relative to today’s conventional solar cells. Furthermore, the fabrication of Quantum Dot Solar Cells is also amenable to inexpensive, high-throughput roll-to-roll manufacturing.
Read the rest at Physorg.
LED light bulbs are far kinder on the environment than old style incandescent light bulbs and they’re selling very well! Looks like good light is shining on the environment.
In the past year, though, lighting manufacturers have introduced LED bulbs in a shape Edison would recognize that put out a decent amount of good-quality light. They still don’t give off light from all sides as incumbent technologies do, but this latest generation of LEDs does a better job dispersing light, which means that you could use one (or a few) for overhead lighting.
The best part is that the prices are coming down. The 40-watt equivalent general light bulb from Lighting Science Group, which is dimmable, costs just under $20. You can buy it online now and in Home Depot stores later this month, along with the LEDs from other manufacturers, including a ceiling down light from Cree.
Sydney turned of their lights earlier this year to raise awareness about climate change and now it appears that the idea is spreading. San Francisco will be powering down for an hour in the near future.
For one hour, on October 20, San Francisco will experience a partial blackout in an effort to raise awareness of climate change and to promote long-lasting energy saving.
Remember that you can save the planet everyday by conserving energy!