LED Outdoor Commercial Flood Lighting
Outdoor Flood Lighting: LED vs. HID
Directional luminaires, sometimes referred to as spot lights or architectural lights, used to light specific outdoor areas like loading docks, signs and billboards, building facades, and walkways next to buildings.
Item ID: 414
Technical Advisory Group: 2012 LED Lighting TAG (#5)
Average TAG Rating: 3.2 out of 5
TAG Ranking Date: 04/05/2012
Outdoor lighting provides security and safety, as well as visual interest and ambient light for activity areas and outdoor displays. While typically white in color, the light from floodlights may also be colored, or color-changing, if that is desired to add drama or branding. It uses a wide variety of beam spreads to target specific areas, broad to narrow, and a single fixture model may offer multiple distribution patterns (not all in the same unit).
Operating hours are typically long and occupancy may be low much of the time, inviting the use of bi-level and/or occupancy switching to save significant amounts ofenergy. If the product is used as lighting for security cameras, the light level must be high enough for the camera to work. The color quality and operating characteristics of LEDS, as well as their lower energy use, make them well-suited to replace many traditional products in this market and save significant amounts of energy. At this time, LEDs appear ready to compete with lower wattage (less than 250W) HID products, but the wattage of cost-effective applications is increasing. The SSL Program of the U.S. DOE is committed to supporting higher performance and lower costs in this technology. High first costs and unfamiliarity with the technology are barriers to new users. 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.
Baseline Description: 250W HID lamp
Baseline Energy Use: 1290 kWh per year per unit
Based on 250W high intensity discharge (HID) lamp (295W luminaire input including ballast) operating 12 hours per day.
Manufacturer's Energy Savings Claims:
Currently no data available.
Best Estimate of Energy Savings:
"Typical" Savings: 40%
Low and High Energy Savings: 35% to 45%
Energy Savings Reliability: 6 - Approved Measure
These savings are from a US DOE Building Technologies Program, prepared by Navigant Consulting (EERE, 2011 Pg 39). For all lamp types, the range is 35-90% with an average of 60%. For HID lighting, the range is 35-45% with an average of 40%. This technology is already in BPA's lighting calculator, so rated ESR 6.
Energy Use of Emerging Technology:
774 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 U.S. DOE SSL Program, "Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications", which report 43.2 million lamps nationwide, of which 4% is assumed to be in the Northwest. (EERE, 2011 Pg 38)
Regional Technical Potential:
0.90 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.
First costs for LED lamps are high but dropping steadily. The DOE SSL program is working hard to improve LED product performance and efficiency while reducing manufacturing costs, and steady progress is being made. The SSL R & D Multi Year Program Plan (Bardsley, 2011) found the cost of an LED luminaire or replacement lamp to be $50/klm (thousand lumens) and the goal for the year 2020 to be $5/klm, and so far most products are on track to meet or beat the target price and performance goals. One case study, from Next Generation Lighting, indicated that replacing a buildings’ existing outdoor halogen floodlights with LED technology could result in an increase in product cost ranging from 30% to over 300% and energy and demand savings ranging from 40% to 70%. This is higher than typical savings for replacement of HID lamps. Cost-effectiveness will need to be calculated on a case-by-case basis. Any examples we use today will change by next month because the technology and pricing are changing so rapidly. Typical paybacks are currently over ten years without incentives.
Flood lighting is similar to area lighting but has a more focused distribution pattern with sharp cut-offs. It tends to be mounted at lower levels so does not need to provide the higher intensity required for roadway and parking lot lighting. It improves safety and security, may work in conjunction with security cameras, may illuminate outdoor display areas, and can be used to enhance the appearances of the facility and grounds. It is often mounted on walls of buildings to illuminate pathways, entryways, stairwells, loading areas, or adjacent parking. It may also be pole- or ground-mounted to illuminate signage, flags or architectural or landscape features. The light beam is tightly controlled, and the Illuminating Engineering Society specifies seven beam spreads from very narrow to very wide spots. Some lights are aimed up to wash walls or light signs. Dark-sky ordinances may restrict upward-directed light in some jurisdictions. The lights typically operate from dusk to dawn and are exposed to all weather conditions and outdoor temperatures. Fixtures may also be specified to be vandal resistant.
LED technology is now able to meet many of these needs very well, and lumen output continues to increase, which will allow more powerful light to be produced.Advantages and notable characteristics of LED lighting in this application include:
- Good weather tolerance. Although overheating must be prevented, cold weather does not hurt LED output. In fact, in some cases performance and longevity may increase in cold conditions.
- The fixtures tend to be tamper resistant since they are integrated, rather than modular units.
- The white light is very directional and provides good visibility. The potential to operate more precisely than dusk to dawn can further increase energy savings compared to traditional technologies.
As lighting energy codes tighten, requiring more controls and less power use, some traditional technologies are eliminated from consideration.In many cases current or promised LED products can replace them.
The DesignLights Consortium (DLC) Qualified Products List (DLC, 2013), often used for utility programs and the Federal Energy Management Program, currently includes an outdoor, wall-mounted luminaire category. The LED Lighting Facts label from the U.S. Department of Energy’s (DOE) Solid State Lighting (SSL) Quality Advocates Program currently lists about 300 commercial products in the outdoor wall-mounted and decorative categories. Being included on either list does not guarantee that a specific product will work in a specific application, but these lists do provide some data that has been verified by scientific tests.
Unique to LEDs are color-programmable models that add color-changing features for fun, interest or corporate branding.
Traditional flood lighting uses high pressure sodium (HPS) technology, if color quality does not matter, and metal halide (MH) or incandescent/halogen technology if color does matter. The 2002 U.S. Lighting Market Characterization Report for DOE (EERE, 2012) found MH had almost 37% of the area lighting market and 40% of the flood lighting market. HPS followed with 22% and 21% market share, respectively (All numbers refer to the installed base). The MH products average 450 system watts each. Some varieties of fluorescent light are also used, either compact fluorescent or induction lamps, which produce high quality white light. Fluorescent light is more diffuse and limited to smaller areas, such as paths, than spotlight applications. Fixtures are available in multiple styles, light distribution patterns, mounting types and lamp options. Typically the lights on photocells operate all night; those with a time clock or manual switching are usually on for fewer hours. Those using incandescent technology have the option to use motion sensors for some applications, which are not generally available for the other products, though some bi-level options have become available for a few products. Cold temperatures result in less light output and slower starting times for some of the products; for others, power interruptions mean a period of darkness before re-strike can occur. The induction lamp offers the longest life, followed by HPS. For security, the HPS light can show movement and shape, but they are not good for identifying colors.
LED floodlights of various types are now on the market, with half a dozen featured in the IES 2011 Progress Report and more entering the market regularly. So far, the light output intensity of LED lamps is capable of replacing up to about 250 W HID lighting, but is still on a path of rapid development. The 2002 U.S. Lighting Market Characterization Report (EERE, 2012) found LED had 0.9% of area and 0.2% of the installed base of flood lighting markets, respectively. The same report hypothesizes that it will take a 255 W LED product to replace a 451 W MH for output, but did not find available products at the time. A more recent similar report uses somewhat different categories, but building exterior lighting had reached about 1% of the installed base. They also note that “the outdoor sector has seen the greatest penetration and growth in LED lamps due largely to their long lifetime (low maintenance cost) and high efficacy (low operating cost).”
LED lamps offer improve color rendering compared with many other lamp types. Incandescent and halogen lamps are more red, mercury vapor is more blue, and high-pressure sodium lamps are more pinkish. LED lamps also have longer expected lives, so reduce maintenance costs. Finally, they are available in more colors for aesthetic effects.
End User Drawbacks:
First costs can be high, and at this time there are no retrofit kits that can be installed in existing fixtures, so new fixtures will be required even if existing ones are not worn out. Retrofit kits are starting to be offered by manufacturers for specific products in other applications and that could happen in this market as well.
Customers need to be able to select a product that will perform as they expect it to, and they need basic information about how to do that and how to identify high-quality products (see Comments below). Color quality has more variations than ever before; consumers do not only have to choose white or yellowish light, they must now also select which hue of white light because the most efficient products tend to run to the high, bluish side of white light. Some utilities already have qualified product lists, and many use the DesignLights Consortium’s Qualified Products List. ENERGY STAR also offers a category for some of these products. Abundant information about basic and advanced aspects of LED development and use are found atDOE SSL Program website, http://www1.eere.energy.gov/buildings/ssl/ .
It can be intimidating to decide which products to buy when they are expensive, are advertised to last from 50,000 hours to over 100,000 hours, have warranties of 5 years, and are often produced by unfamiliar companies. With lifetimes that long (service lives of 10 to 20 years or more), it is unlikely that the consumer will be able to find exact replacements – even if the company that supplied the product is still in business.
Because LED product 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 they capture the savings available now? With the life expectancy of these products measured in decades, jumping in at a high first cost can be risky.
Standards are still under development in many areas, so advertisers can make claims with little back-up or consistency with other manufacturers’ products. Standards development is ongoing and should improve the situation, as do the Lighting Facts labels and testing requirements to participate in some programs.
Operations and Maintenance Costs:
O & M costs should drop significantly because LED products should last many years longer than competing products, except perhaps some of the induction products. A bigger risk to ending the life of a product might be obtaining a newer model with better performance and features or style. Cleaning would be needed at about the same rate as similar products. Demand costs, if applicable, should also be reduced as the installed wattage drops significantly.
The current standard considers an LED product to have served its useful life when it produces 70% of its original light output. The Illuminating Engineering Society (IES) Standards LM-80 and TM-21 now exist to help predict lifetimes in a consistent manner. Many products on the market may have LM-80 testing, but TM-21 just became effective in the summer of 2011 so most existing products may not have been tested that way yet. Advertising literature of some highly regarded products ranges from 50,000 to well over 100,000 hours, but the testing standard is not always specified, or may be for only a component of the luminaire, and all components may not have the same life. The quality of assembly and materials can also compromise the life of the luminaire even though the light emitting diode has not itself yet failed. Until modular components are available for field replacement, any partial failure effectively kills the luminaire and a full replacement is required. Meanwhile, there is no need to stock spare lamps.
For long throw and punch lighting needs, high-powered MH is the main competitor. For broader area lighting, the fluorescent technologies offer long life, low cost white light that can be easily switched or dimmed.
Some colored gels are available for MH products if color is desired. Where cold temperatures are not an issue, compact fluorescent products can offer diffuse white light, but do not generally perform well for frequent switching or with electronic controls.
Reference and Citations:
2010 US Lighting Market Characterization
Navigant Consulting, Inc.
Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications
U.S. Department of Energy, Building Technologies Program
Solid-State Lighting Research and Development:Multi Year Program Plan
DesignLights Consortium Qualified Products List
DesignLights Consortium, Northeast Energy Efficiency Partnerships, Inc.
Energy Efficiency & Renewable Energy
Where Can We Use SSL Today?
Energy Efficiency & Renewable Energy
Energy Efficiency & Renewable Energy
Solid-State Lighting GATEWAY Demonstration Outdoor Projects
U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy
International Dark-Sky Association
• Standard Development for Solid State Lighting
Energy Efficiency & Renewable Energy
2011 Progress report
• IES Lighting Design and Applications
California Lighting Technology Center,
Bi-Level LED Bollards
California Energy Commission’s Public Interest Energy Research Program