LED Street Lighting Saves 85% Energy

An independent two-and-a-half-year global pilot of LED lamps in 15 trials across 12 cities including New York, London and Kolkata, has found that LED street lighting can generate energy savings as high as 85%. The programme also indicates that citizens of pilot cities prefer LED lighting, citing social and environmental benefits.

The findings of LightSavers are presented for the first time in a new report entitled, Lighting the Clean Revolution: The Rise of LED Street Lighting and What it Means for Cities.

The report explores the global market status and potential for LEDs and provides guidelines for policymakers and city light managers who want to scale-up large LED retrofits. It was launched as part of the Clean Revolution campaign at the Rio+20 UN Global Compact Corporate Sustainability Forum and produced by The Climate Group in partnership with Philips.

Key findings include:

• Surveys in Kolkata, London, Sydney and Toronto indicated that between 68% to 90% of respondents endorsed LEDs city-wide rollout. Benefits highlighted included improved safety and visibility.
• LED lighting trialed lifespan ranges from 50,000 to 100,000 hours indicating a high return on investment.
• LED failure rate over 6,000 hours is around 1%.
• The Climate Group and Philips are calling for an international low carbon lighting standard to be created and implemented ensuring that citizens worldwide have access to energy efficient outdoor lighting.

LEDs & Energy-Saving Lights

With a push to reduce energy consumption, light-emitting diodes and other energy-saving lights are increasingly desirable and available alternatives to traditional incandescent bulbs. Although more expensive than their incandescent counterparts, LEDs and other energy-saving bulbs cost less to operate over their lifespans because they generate more light with less electricity. The energy savings ultimately offset the cost of the bulb.

LEDs

According to Energy Star, as of 2011, LED bulbs use only 20 to 25 percent of the energy of incandescent bulbs, with efficiency matching or exceeding fluorescent lights . In addition to energy efficiency, a U.S. Department of Energy report notes that the "benefits of LEDs include long operating lifetime, lower maintenance and life-cycle costs, reduced radiated heat, minimal light loss, dimmability, controllability, directional illumination, durability, safety improvements, and light pollution reduction.".

Compact Fluorescent Bulbs

Fluorescent lighting has been around for decades, but compact fluorescent lamps are another energy-efficient replacement for incandescent bulbs. CFLs are simply smaller versions of the long lighting tubes used in commercial and industrial operations. Providing an energy savings of about 75 percent compared to incandescents, these bulbs have come a long way since their introduction. They are now available in a wide variety of styles and a range of colors. Additionally, there are now "instant on" versions, as well as styles suitable for use with dimmer switches.

Halogen Bulbs

Another energy-saving choice, halogen bulbs are incandescents that use halogen gas around the filament; this increases the efficiency and lifespan of the bulb. Halogens use only about 25 percent less energy than a traditional incandescents, however, so are a distant third behind LEDs and CFLs in energy efficiency.

Replacing Lights

To get light quality that is comparable to your old incandescent bulbs, choose energy-efficient bulbs based on the lumens they produce, rather than the number of watts they use. A lumen is simply a measure of the amount of visible light a bulb produces. A traditional 100-watt incandescent bulb produces about 1,600 lumens, for example, so a replacement LED or CFL should have a rating for the same output. As of mid-2011, new light bulb labels will show both a bulb's wattage and brightness in lumens. The labels will also provide information about the bulb's appearance -- if its light looks "cool" or "warm," if it contains mercury, and its estimated energy cost and life expectancy.

Source National Geography. Green Living. LEDs Energy-Saving Lights

by Ann Deiterich, Demand Media

What does lumen mean?

Lumens are more accurate way of measuring the amount of light a particular bulb is putting out, because lumens are a direct measurement of light output. Wattage, even though it is what people have become accustomed to seeing on packaging and measuring how much light they are seeing, it is not really an accurate way to measure light output. Just because a light bulb uses a particular amount of energy to run, does not mean that it directly correlates with the amount of light that is put out. With a variety of energy efficient CFLs, LEDs and Halogen lamps coming onto the market on a regular basis that do not use nearly the same amount of energy as incandescent bulbs it makes sense for people to move away from thinking about wattage when they purchase a bulb and start thinking about lumens.

Are LED Lights Eco-Friendly?

Light-emitting diodes are an eco-friendly lighting choice. LEDs are an energy-efficient alternative to traditional incandescent light bulbs, which waste 90 percent of the energy they consume on heat. Other energy-efficient lighting options include halogen incandescent bulbs and compact fluorescent lamps. All incandescent and fluorescent lights produce light that flows in all directions, wasting light as well as heat.

LED Technology

LEDs are a rapidly advancing technology that uses energy more efficiently and can save energy in indirect ways, such as with air-conditioning costs. LEDs use small, powerful sources of light that illuminate when electrons move through semiconductor materials. They shine in only one direction, produce a small fraction of the heat of fluorescent and incandescent lights, and lasting longer than other types of lighting.

Energy Star

Energy Star, a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy, labels LED lights that meet its energy-efficiency guidelines. Although LED lighting design creates efficiencies, poorly designed LED lights do not meet the potential of the technology. Energy Star guidelines require that LEDs consume at least 75 percent less energy than incandescent bulbs and last 15 times longer. In addition, the bulb must turn on instantly.

Savings

LED low energy-usage saves money in utility bills. As of 2011, an Energy Star-qualified LED bulb has an average operating cost of $1 per year. That compares to annual costs of $1.20 for an Energy Star-qualified compact fluorescent bulb, $3.50 for a halogen incandescent bulb and $4.80 for a traditional incandescent bulb. In addition, an Energy Star-qualified LED bulb's longer life -- ranging from a minimum of 15 times longer than a traditional incandescent bulb to a maximum of 25 times longer -- means there is much lower turnover of bulbs in your house.

Future Savings

Technological advances with LEDs raise hopes for significantly reducing electricity usage in the United States. LED lighting could cut the electricity demand in the country by 1/3, according to the U.S. Department of Energy. The estimated savings from that adoption would total $265 billion, including preventing the construction of 40 new power plants.

References

1. Energy Star: LED Light Bulbs
2. U.S. Department of Energy: Energy Efficiency & Renewable Energy: Energy Savers Lighting Choices: Frequently Asked Questions
3. U.S. Department of Energy: Energy Efficiency & Renewable Energy: Energy Savers: Lighting Choices to Save You Money
4. Energy Star: What are LEDs?