LED "High-Mast" Highway Lighting
High Mast Lighting: LED vs. HPS
LED lighting for high mast lighting (above 100') for highway interchanges and high traffic areas.
As of October 2012, LED high mast lighting is entering the market. LEDs for high-lumen-output applications are inherently modular; that is, to achieve the high-lumen output demanded by highway lighting, many more LEDs are required in the fixture than for lower-output applications. This makes the first cost for LEDs more expensive. Thus, the cost effectiveness of LED highway lighting will likely continue to be a constraint for several more years. In areas where electricity costs exceed $0.10/kWh the technology may make sense, especially when reduced maintenance is calculated, and lamp life has moved closer to 100,000 hours/25 years. The movement toward adaptive lighting,( reducing light in low use periods) may result in using more controls on roadway lighting. Numerous manufacturers are now offering these products, and jurisdictions such as Los Angeles are beginning to deploy LED highway lighting. The Maine Department of Transportation is retrofitting 1000W HPS fixtures at some interchanges with a 4 year payback with 66% energy savings. Advantages of LED lighting for this application include:
- Higher correlated color quality allowing lower light levels for the same visual acuity.
- Longer life -- LEDs are often rated with 3-4 times the life of HPS and HID lights. Longer burn time reduces maintenance costs.
- Directional control. LEDs give very directional light, making it potentially easier to control. This can help reduce glare, provide more even light distribution, reduce light pollution, and provide more light where it is needed with good design and optics. Dimming is also possible.
Energy Savings: 60%
Energy Savings Rating:
Limited Assessment What's this?
|1||Concept not validated||Claims of energy savings may not be credible due to lack of documentation or validation by unbiased experts.|
|2||Concept validated:||An unbiased expert has validated efficiency concepts through technical review and calculations based on engineering principles.|
|3||Limited assessment||An unbiased expert has measured technology characteristics and factors of energy use through one or more tests in typical applications with a clear baseline. |
|4||Extensive assessment||Additional testing in relevant applications and environments has increased knowledge of performance across a broad range of products, applications, and system conditions. |
|5||Comprehensive analysis||Results of lab and field tests have been used to develop methods for reliable prediction of performance across the range of intended applications.|
|6||Approved measure||Protocols for technology application are established and approved.|