LED Screw-in Replacement Lamps for HID Sources
Outdoor and High/Low Bay Lighting: LED vs. HID
LED screw-in replacement lamps employing medium and mogul bases for HID sources (primarily HPS and MH) in outdoor and commercial high bay and low bay applications.
Item ID: 637
Lighting--Lamps & Ballasts
LED screw-in replacement lamps for high intensity discharge (HID) sources (e.g. luminaires or retrofit kits) are a potential, relatively inexpensive option for lighting energy efficiency retrofits in a variety of lighting applications. These applications include decorative streetlights, cobra streetlights, wallpacks, outdoor area, outdoor flood and interior high bay/low bay. They are best suited to specialty applications where existing luminaires have unusually high value and the LED screw-in replacement lamps may have a price advantage over new integral LED luminaires.
Market and technological barriers to widespread adoption remain. Lumen maintenance, thermal management, light distribution, and physical mounting can be of concern for LED screw-in replacement lamps, as the design must allow for proper operation in a wide variety of housings. Other performance risks include inappropriate light distribution from asymmetric lamps and poor performance at high temperatures.
Baseline Description: 100 W high pressure sodium (HPS) lamp in a decorative streetlight application.
Baseline Energy Use: 604 kWh per year per Unit
Baseline energy use is calculated assuming a 100 W HPS (high pressure sodium) street lighting consuming 138 W/fixture and operating all night (4380 hr/yr).
138 W * 4,380 hr/yr / 1000 W/kWh = 604 kWh/yr
Metal halide, mercury vapor, and low pressure sodium are alternative baseline technologies for streetlighting applications, although these technologies are in limited use. However, metal halide lamps are a fairly common alternative baseline for other applications, such as wallpacks, and interior high bay/low bay.
Manufacturer's Energy Savings Claims:
"Typical" Savings: 60%
Savings Range: From 50% to 80%
Manufacturer websites and literature typically indicate “HID equivalent” wattages for which the lamp is intended. For instance, “35W LED Retrofit Lamp for replacing HID lamps up to 150W.” (Light Efficient Design, 2015) Manufacturer energy savings are calculated from these claims.
Best Estimate of Energy Savings:
"Typical" Savings: 50%
Low and High Energy Savings: 40% to 60%
Energy Savings Reliability: 6 - Approved Measure
Energy consumption in both the baseline and proposed case includes any associated ballast energy use.
Savings are based on using LED screw-in replacement lamps in decorative street lighting applications. This application is particularly suitable for screw-in replacement lamps because it is a specialty application where existing luminaires have unusually high value. Savings for other applications are expected to be of the same magnitude.
LED sources are typically compatible with automatic controls and frequent switching does not reduce lifetime as much as it does for incumbent HID sources. LED screw-in replacement lamps can therefore make greater energy savings possible using simple controls such as on/off timers and on/off occupancy sensors. However, most currently available LED screw-in HID replacements are not compatible with the deeper energy savings achieved by advanced networked controls using high-end trim, bi-level occupancy sensing, and dimming for daylight harvest.
Energy Use of Emerging Technology:
302 kWh per Unit per year
Energy Use of an Emerging Technology is based upon the following algorithm.
Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
While this is an approved measure, suitable lighting performance and resulting energy savings will be very dependent on the specific application and the specific replacement lamp product selected. The Lighting Research Center (LRC) Phase 2 report (Radetsky & Leslie, 2015) commissioned by BPA showed a wide range of lighting performance for LED screw-in replacement lamps from different manufacturers.
Potential number of units replaced by this technology:
Based on Navigant's 2010 Market Characterization (Navigant, 2012) for U.S. DOE SSL Program, the total number of HID lamps installed in the U.S. is 144 million. Using the author’s estimate that approximately half of these are suitable for LED screw-in replacement lamps, the national total potential is 72 million. Assuming a Northwest potential of 4% of the national potential (the Northwest is about 4% of the population of the U.S.), the total Northwest technical potential is 2.9 million. Technical Potential = 4% * 71,000,000 = 2,880,000 units.
Regional Technical Potential:
0.87 TWh per year
Regional Technical Potential of an Emerging Technology is calculated as follows:
Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)
Installed first cost per: Unit
Emerging Technology Unit Cost (Equipment Only): $70.00
Emerging Technology Installation Cost (Labor, Disposal, Etc.): $40.00
Baseline Technology Unit Cost (Equipment Only): $12.00
Cost shown above are based on an LED decorative streetlight application with a 100W HPS lamp, replaced by a suitable LED screw-in equivalent. Labor cost to replace an HID lamp with a screw-in LED replacement lamp is estimated at 0.5 hrs and $80/hr.
Simple payback, new construction (years): 2.1
Simple payback, retrofit (years): 4.0
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
As part of the LRC Phase 1 report (Radetsky & Leslie, 2015), a survey of case studies of screw-in LED replacement lamp installations was conducted. Of 15 case studies found, five claimed payback of less than three years. Most of the case studies are based on manufacturers’ claims and/or municipal publicity. Until comprehensive quantitative and qualitative evaluations are published, caution is warranted regarding these claims.
The LRC Phase 1 report (Radetsky and others, 2014) found the average price of LED screw-in replacement lamps was very roughly 30% of the average price of integral LED luminaires. However, this is likely to vary by application. For instance, the price of new integral LED cobra head streetlights has declined dramatically and the price advantage of a screw-in replacement lamp will be low. On the other hand, the price of a new integral LED decorative streetlight is very high, making the low cost of a screw-in LED replacement lamp attractive.