LED Parking Garage Lighting
Parking Garage Lighting: LED vs. Conventional
Ceiling-mounted luminaire for parking garage applications, suitable for outdoor and other environments open to the elements.
Item ID: 398
Technical Advisory Group: 2012 LED Lighting TAG (#5)
Average TAG Rating: 3.7 out of 5
TAG Ranking Date: 04/05/2012
TAG Rating Commentary:
- There are a lot of really good products available now. We are at the point where the only challenge is education of the market players, and assuring good system design practices.
A study for the U.S. Department of Energy (USDOE), (Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications) estimates that in 2010 there were 110 million lighted parking spaces in the U.S., which together use 28.1 TWh of electricity annually. The lighting provides safety and security for vehicle traffic and pedestrians. The location of light fixtures can make maintenance difficult or disruptive. LED parking garage lighting can provide high-quality light for a long time and also provide substantial energy savings, often in the range of 50-80%.The use of "self-cleaning glass or coatings" on fixtures could reduce the need for cleaning which would make the most of long-life and reduced maintenance claims. Life-cycle cost analysis can make the product look more attractive, in spite of high first costs. Automated controls can significantly increase energy savings in many cases, without hurting lamp life. The potential energy savings from implementing LED technology in parking garages is estimated at 16.9 TWh/yr if LEDs achieved 100% market penetration overnight. As of 2010, LEDs are installed in about 4.6% of the market and are credited with saving 1.4 TWh in 2010. (http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/nichefinalreport_january2011.pdf, p52)
Resources are available to help building owners select products, and some utilities are offering incentives specific to LEDs.
The number of products, features and controls is increasing and the technology continues to enjoy support from the USDOE to increase efficiency and performance as well as reduce costs. Energy codes are increasingly restricting the watts per square foot allowed and requiring occupancy and daylighting controls in more spaces, including making simple lamp/ballast replacement projects subject to current code requirements. In combination, these factors will increase the need for more efficient and controllable products.
Retrofit kits for existing luminaires are also available. Well-designed retrofit kits can deliver the same benefits of integral luminaires.
Baseline Description: 175 W Pulse Start MH
Baseline Energy Use: 1822 kWh per year per unit
According to the U.S. Department of Energy, the prorated average parking garage light uses 121W and operates 18 hours per day.
# Lamps in US (x1000)
US Baseline Wattage (MW)
| 86 |
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In NW (4%)
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Citation: http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/nichefinalreport_january2011.pdf , pages 35-36.
Manufacturer's Energy Savings Claims:
Currently no data available.
Energy Use of Emerging Technology:
692.4 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.))
Potential number of units replaced by this technology:
Based on Navigant's 2011 report for the USDOE SSL Program, "Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications" http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/nichefinalreport_january2011.pdf
Regional Technical Potential:
1.57 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)
Currently no data available.
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
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.
Cost effectiveness can vary widely depending on incentives that may be available. The price of LED products continues to fall while the product improves. The USDOE has stated: “Evaluated on a lifecycle cost basis, SSL products can be competitive in parking lot applications because of their energy savings, directionality, controllability, aesthetic appeal, and maintenance savings. Nevertheless, selecting LED parking lot lighting products is a complex process. Specifiers must weigh such factors as installation geometry, local ordinances, and acquisition costs to determine the right solution for each location. Lighting levels also must be carefully considered. Many designers find LED systems can achieve satisfactory lighting levels with significantly less light (e.g., 70% below ASHRAE levels) than incumbent technology.” (http://www1.eere.energy.gov/buildings/ssl/where_ssl_today.html)
The Federal Energy Management Program (FEMP) has decided that LED systems, including controls, should be at the top of the list when selecting a parking garage system. In a FEMP case study at a Cleveland Hospital, projected energy savings were 82% and simple payback was 4.2 years. These results were close to the results of the GATEWAY study in Portland, Oregon in 2008. They used an energy rate of $0.065/kWh on a retrofit of an HPS-to-LED system and found simple paybacks of 3.9 to 6.5 years on a 24/7 operating schedule, depending on what fixture was used (they tested two versions of one type). For new construction applications, the simple payback was 1.7 to 2.6 years; the shorter periods were calculated with a national average electricity cost of $0.11/kWh. A 63% cost savings in annual operating costs was found with the newest LED model that cost $62/fixture.
Retrofit kits can be lower cost than integral luminaires, but not always as the price of integral luminaires continues to decline. In addition, depending on the design of the retrofit kit, the labor hours required to gut an existing housing and install a retrofit kit may be greater than the labor hours required to simple replace the entire luminaire.
Parking garages are prime candidates for energy-saving lighting because these spaces are large and the lights are often left on all the time – regardless of occupancy – especially on underground floors, although the USDOE estimates they operate an average of 18 hours/day. Parking garage lights differ from outdoor parking lights because they are lower wattage, need to be vibration resistant, and are mounted on walls and/or typically low ceilings where a low profile is essential so vehicles can pass under them. Vandal-resistant fixtures are often necessary. LEDs are penetrating this market; some manufacturers of multiple technology products are finding that LEDs account for 30% of their sales.
While heat is the enemy of LED technology, cold is its friend: LED performance is not degraded, and is sometimes better, in cold conditions. LED lighting for parking facilities has reached the point where the light output and efficacy meet or beat the traditional lighting sources of metal halide (MH), induction and high-pressure sodium (HPS) systems. LEDs, with a good fixture design, offer a more even distribution of light without the familiar “hot spots” created by other lights. Because of this, measured light levels can be reduced with LEDs in some facilities while still improving visibility. Fixtures may be parking garage-specific or low-bay fixtures.
LED technology can generate significant savings in parking facilities, indoors and out, over traditional technologies, in part because they can be controlled more easily with occupancy or daylighting sensors, so the lights are on only when needed. The directionality of the light can be used to good advantage, especially in facilities with one-way traffic flow, where glare can easily be controlled for drivers. The white light generated by LEDs makes it easier to identify vehicles by color than HPS systems. The long life should reduce maintenance costs as well.
In spite of all the benefits, choosing to use LED products in this application is not a “no brainer.” The specific site situation and products being considered must be carefully assessed. The speed with which LED technology is improving and the number of new products entering the market requires consumers to thoroughly research their options right before making a purchase.
Retrofit kits for existing luminaires are also available. Well-designed retrofit kits can deliver the same benefits of integral luminaires. Retrofit kits typically include a complete LED lighting system, including LED modules and/or arrays, optics, driver, and mounting hardware. Retrofit kits can be lower cost than integral luminaires, but not always as the price of integral luminaires continues to decline. Retrofit kits allow reuse of existing housings, which can be of particular benefit for some applications. On the other hand, lumen maintenance, thermal management, light distribution, and physical mounting can be of concern for retrofit kits, as the design must allow for proper operation in a wide variety of housings. For reliable performance, utilize retrofit kits certified for compatibility with the specific make and model number of the existing street lights.
Traditionally, parking garages have used HPS, MH and, more recently, induction or linear fluorescent lighting. Induction, HPS and MH systems are typically left on all the time or used during business hours and controlled manually or by timers. Linear fluorescents offer easier switching than HPS or MH, which makes it possible to use controls such as occupancy or daylight sensors; however, many linear fluorescents are not controlled.
HPS is a long-lasting system, but their poor color rendering can make it difficult to identify vehicles and may contribute to a dingy feeling, adding to the perception that the area is less safe. Most people prefer white light that renders colors well so they can more confidently assess who is near them, what is going on around them, and can more easily identify their own vehicle.
Induction is an expensive “white light” option compared to MH, but is more affordable than early LED systems. Induction also offers a longer lamp life than the other choices – 100,000 hours for the lamps but about 60,000 hours for the generator (similar to a ballast) – so is especially useful for reducing maintenance. Until recently, induction lighting could not be dimmed.
Linear fluorescents use relatively large, low-profile fixtures, with multiple lamps per fixture, so a lamp failure does not create a completely dark area. They can be controlled easily, but are sensitive to very cold temperatures. The newer T8 fluorescent systems are much improved over old T12 technology in efficiency, lumen maintenance, lamp life and response to cold weather.
Federal energy efficiency standards (see http://www1.eere.energy.gov/buildings/appliance_standards/) are impacting which products will remain on the market, and codes are continuing to require less lighting power density (watts/square foot).
The U.S. Department of Energy (USDOE), through the Solid State Lighting (SSL) program’s CALiPER (Commercially Available LED Product Evaluation and Reporting) project, has results for various lighting products suitable for use in parking garages (Round 10). The GATEWAY Demonstration Program has case studies of many projects. One of these looks specifically at parking garage lighting: “LED Parking Garage Lighting: Providence Portland (OR) Medical Center in 2008,” and others focus on parking lot lighting. Like LED technology in general, products for this application continue to evolve, with lower costs, more light output, improved efficiency and more control options. A good general background of the technology can be found at the USDOE’s SSL website.
In 2010, LEDs made up 4.1% of parking garage lighting in place. In the 2007 report, Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications, no LED installations were used in parking applications. Since then, a more recent volume of that report notes that “Garage lighting has led the transition to LED in the parking sector, with some garage lighting manufacturer’s noting nearly 30% of current sales are LEDs.”
End User Drawbacks:
First costs are still high, but prices are dropping. Life cycle costs should be used in analyzing the system.
Because LED availability, price and quality are improving so rapidly, many potential customers may wonder if “now” is the right time to buy. Is it worth waiting until next year to buy, when the available product will be higher quality, more efficient and cost less, or should consumers capture the savings available now? Given that the life expectancy of the products is measured in decades, jumping in at a high first cost can be seen as risky.
Unfamiliarity with the products and how to select them can be intimidating to potential owners. See References for some helpful resources. A test installation is the best way to determine whether a fixture will work in a specific application, and they can be quite expensive.
Operations and Maintenance Costs:
At this time, there are no additional costs for disposal of LED products at end of life and there is some interest in making them recyclable by the manufacturers. Mercury-containing products are hazardous waste that incurs additional charges and paperwork. The long life of LEDs, if realized, should greatly reduce maintenance, though parking garages tend to be dirty and cleaning will still be necessary. At this time, LED drivers do not last as long as the LEDs. Replacing drivers, if it can be done, will involve additional maintenance costs that will vary, depending on whether a field replacement or factory replacement is necessary.
LEDs are expected to last around 50,000 hours, though they have not been installed long enough to verify in real-world conditions. At this time, LED drivers do not last as long as the LEDs, so the effective life might be shorter. The new IES TM-21 standard is helping manufacturers calculate lamp life. Learn more about standards and LEDs at Understanding LED tests: IES LM-79, LM-80, and TM-21: .
For comparison, existing lamp life of other technologies range from:
- Linear fluorescents – 24,000 to 46,000 hours.
- HPS – 24,000 to 40,000 hours.
- Induction – 100,000 hours, but a new generator may need to be installed around 60-70,000 hours.
- Pulse-start metal halide – 10,000 to 15,000 hours.
The effective life of well-designed retrofit kits is expected to be equivalent to that of new luminaires, however can be impacted by the housing in which the retrofit kit is installed. The DLC specifies a minimum required lumen maintenance for retrofit kits that is equal to the minimum required lumen maintenance for new luminaires. This lumen maintenance must be demonstrated in a representative housing.
The Commercial Building Energy Alliances (CBEA) considered linear fluorescent, induction and LED in making their parking facility lighting specification. For white light, linear fluorescent is probably the most competitive and has the highest lumen maintenance, but is not necessarily the most popular technology. A good fluorescent system would not be a great candidate for a retrofit, but might still be a great choice for new construction. Pulse-start MH might be preferred where the installation is exposed to a wide temperature range. Induction lighting still offers a long life and more fixtures and control options have become available in the last few years, but LEDs are bringing stiff competition as prices come down. Linear fluorescent and MH will have higher maintenance costs than induction or LED. Old HPS, incandescent, probe-start MH, and T12 systems would all be excellent candidates to upgrade to LED.
Reference and Citations:
LED Lighting Facts
U.S. Department of Energy
Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications
U.S. Department of Energy, Building Technologies Program
Exterior Lighting for Energy Savings, Security and Safety
Pacific Northwest National Laboratory
DesignLights Consortium Qualified Products List
DesignLights Consortium, Northeast Energy Efficiency Partnerships, Inc.
Solid State Lighting Program
U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy
Where Can We Use SSL Today?
Energy Efficiency & Renewable Energy
Solid-State Lighting GATEWAY Demonstration Outdoor Projects
U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy
CBEA High-Efficiency Parking Structure Lighting Specification
Commercial Building Energy Alliance
Case Study: Dramatic Energy Savings for Sacramento with Bi-level LED Parking Garage Retrofits
California Energy Commission
LED, Controls and Commissioning: The Perfect Brew
Energy Center of Wisconsin
Outdoor Lighting Guidance
Energy Efficiency & Renewable Energy
CALiPER Application Summary Reports
U.S. Department of Energy, Solid-State Lighting Program
Myer, et. al.,
FEMP Exterior Solid-State Lighting Initiative: High Performance Parking Structure Lighting
U.S. Department of Energy, Federal Energy Management Program
Bi-Level LED Lighting Systems
Sacramento Municipal Utility District
FEMP Exterior Solid State Lighting Initiative: High-Performance Parking Lot Lighting for Federal Facilities
Federal Energy Management Program
Demonstration Assessment of Light-Emitting Diode (LED) Area Lights for Commercial Garage, Host Site: Providence Portland Medical Center, Portland, Oregon
U.S. Department of Energy
Lighting Checklist —Parking Garage Lighting
U.S. Department of Energy, Energy Efficiency & Renewable Energy
Bi-level Fluorescent Parking Garage Luminaires: University of California, Santa Barbara
California Energy Commission, Public Interest Energy Research Program