Covered Product Category: Fluorescent Ballasts
Updated December 2011
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Lighting as a Key Energy Conservation Measure
Facilities with significant potential savings in lighting may be able to bundle lighting upgrades with heating, ventilation, air conditioning, and other energy conservation measures into a Utility Energy Service Contract (UESC) or Energy Savings Performance Contract (ESPC). Because of the substantial cost and energy savings potential, replacing lighting can be a key component in financing facility retrofits. For more information on funding opportunities, visit the FEMP Project Funding Web page.
FEMP provides acquisition guidance and Federal efficiency requirements across a variety of product categories, including fluorescent ballasts, which are a FEMP-designated product category. Federal laws and executive orders mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.
Federal agencies are required by the National Energy Conservation Policy Act (P.L. 95-619), Executive Order 13423, Executive Order 13514, and Federal Acquisition Regulations (FAR) Subpart 23.2 and 53.223 to specify and buy ENERGY STAR®–qualified products or, in categories not included in the ENERGY STAR program, FEMP-designated product categories, which are among the highest 25% of equivalent products for energy efficiency.
Information about energy-efficient fluorescent ballasts in this section includes the following:
- Energy Efficiency Requirements
- Determining Cost-Effectiveness
- Contracting Considerations
- Buying Energy-Efficient Fluorescent Ballasts
- Buyer Tips: How to Choose Efficient Products
- For More Information
Energy Efficiency Requirements for Fluorescent Ballasts
The following tables describe the requirements and options that Federal agencies must keep in mind when procuring energy-efficient fluorescent ballasts. Ballast efficacy factor (BEF) is the ratio of the ballast factor (BF) to input watts; it measures the efficiency of the lamp/ballast system relative to other systems using the same type and number of lamps. BF is the ratio of the light output of a lamp(s) operated by a ballast to the light output of the same lamp(s) operated by a reference ballast at rated current and voltage. Ballast luminous efficiency (BLE) is a new metric proposed for the fluorescent ballast test procedure and upcoming Federal ballast efficiency standards and is provided for reference.
|Table 1-1. Efficiency Requirements for Ballasts Driving 4-foot T8 Lamps1|
|Start Type||Instant Start||Programmed/Rapid Start|
|Lamp Type||Number of Lamps||Required BEF (BLE)||Best Available BEF (BLE)||Number of Lamps||Required BEF (BLE)||Best Available BEF (BLE)|
|F32T8 (32 W)||1||BEF 3.06
1 Requirements as of November 1, 2011. Note that these ballasts can also drive T8 lamps of other wattages, specifically F32T8 reduced-wattage lamps of 30 watts, 28 watts, or 25 watts. When the ballasts in the table are used with these lower wattage lamps, the end user will save additional energy.
|Table 1-2. Efficiency Requirements for Ballasts Driving 8-foot T8 Lamps1|
|Lamp Type||Number of Lamps||Required BEF (BLE)||Best Available BEF (BLE)|
|F96T8 (59 W)||1||BEF 1.57 (BLE 0.89)||BEF 1.64 (BLE 0.93)|
|2||BEF 0.82 (BLE 0.93)||BEF 0.84 (BLE 0.96)|
1 Requirements as of November 1, 2011. Note that these ballasts can also drive reduced-wattage lamps, such as F96T8 57-watt lamps. When the ballasts in the table are used with these lower wattage lamps, the end user will save additional energy.
|Table 1-3. Efficiency Requirements for Ballasts Driving T5 Lamps1|
|Lamp Type||Number of Lamps||Required BEF (BLE)||Best Available BEF (BLE)|
|F28T5 (28 W)||1||BEF 3.08 (BLE 0.86)||BEF 3.33 (BLE 0.93)|
|2||BEF 1.64 (BLE 0.92)||BEF 1.69 (BLE 0.95)|
|F54T5HO (54 W)||1||BEF 1.65 (BLE 0.89)||BEF 1.79 (BLE 0.97)|
|2||BEF 0.86 (BLE 0.93)||BEF 0.93 (BLE 1.00)|
1 Requirements as of November 1, 2011. Note that these ballasts can also drive reduced-wattage lamps, such as 49-watt and 51-watt lamps. When the ballasts in the table are used with these lower wattage lamps, the end user will save additional energy.
The best available ballast efficacy factors in the above tables assume that full-wattage lamps are used with each ballast type (the same lamps used for the required ballast efficacy factor levels) for a fair comparison of ballast performance. Note that the actual "best available" combination would use reduced-wattage lamps for even more energy savings.
An efficient product is cost-effective when the energy cost savings over its functional lifetime exceed any initial incremental cost above a less-efficient model (i.e., energy cost savings is greater than additional costs at time of purchase). Federal purchasers may assume that ENERGY STAR–qualified products and products meeting FEMP-designated efficiency requirements are life cycle cost-effective. However, users wishing to determine cost-effectiveness for their application may do so using the cost-effectiveness example in table 2.
Products meeting FEMP-designated efficiency requirements or ENERGY STAR performance specifications may not be life cycle cost-effective in certain low-use applications, such as when a device is purchased for backup purposes and will remain in off mode for most of its useful life. For most other average or high-use applications, purchasers will find that energy-efficient products have the lowest life cycle cost.
|Table 2. Cost-effectiveness Example|
|Performance for a Fluorescent Two-Lamp Ballast||Less-Efficient Model Instant Start||Required Level Instant Start||Best Available Level Instant Start||Less-Efficient Model Programmed Start||Required Level Programmed Start||Best Available Level Programmed Start|
|Ballast Efficacy Factor||1.52||1.60||1.66||1.44||1.57||1.60|
|Input Power (watts)||58||55||53||61||56||55|
|Annual Energy Usage (kilowatt hours)||209||198||191||220||202||198|
|Annual Energy Cost||$18.78||$17.82||$17.18||$19.80||$18.16||$17.82|
|Annual Energy Cost Savings||-||$0.96||$1.61||-||$1.64||$1.98|
|Lifetime Energy Cost||$204||$194||$187||$215||$198||$194|
|Lifetime Energy Cost Savings||-||$10||$17||-||$7||$10|
Using the Cost-Effectiveness Table
In the example shown in table 2, a fluorescent instant-start two-lamp ballast meeting the required ballast efficacy factor of 1.60 or higher is cost-effective if its purchase price is no more than $10 higher than that of a less-efficient model instant-start two-lamp ballast. A fluorescent programmed-start two-lamp ballast meeting the required ballast efficacy factor of 1.57 or higher is cost-effective if its purchase price is no more than $7 higher than that of a less-efficient model programmed-start two-lamp ballast.
Calculating Lifetime Energy Cost Savings
To calculate lifetime energy cost savings for a different electricity price, multiply the savings in the above table by this ratio:
(Your price in ¢/kWh) ÷ (9.0¢/kWh).
Similarly, for different hours of operation, multiply savings by this ratio:
(Your annual hours of use) ÷ (3,600 annual hours of use).
Energy use and performance of a fluorescent lamp ballast depends on the performance of the lamp(s) and the fixture, which together with the ballast(s) make up a luminaire. The example in table 2 shows the cost-effectiveness of efficient fluorescent ballasts used in combination with efficient lamps. The example also shows lifetime energy cost savings for the improved ballast.
The less-efficient model uses two standard T8 lamps with standard electronic ballasts performing in the lowest quartile (bottom 25%) of ballast efficacy factors of models on the market. The required level models use two high-performance T8 lamps with high-performance instant-start and programmed-start ballasts, respectively, performing in the highest quartile (top 25%) of models on the market. The best available models use two high-performance T8 lamps with high-performance instant-start and programmed-start ballasts with the best available efficiency among models on the market.
For both examples, lifetime energy cost is the sum of the discounted value of annual energy costs, based on 3,600 operating hours per year and an assumed ballast life of 13.9 years. The assumed electricity price is 9¢ per kWh, the Federal average electricity price in the United States. Future electricity price trends and a discount rate of 3.0% are based on Federal guidelines effective from April 2010 to March 2011.
These requirements apply to all forms of procurement, including construction guide specifications and project specifications; renovation, repair, maintenance, and energy service contracts; lease agreements; acquisitions made using purchase cards; and solicitations for offers. Energy efficiency requirements should be included in both the evaluation criteria of solicitations and the evaluations of solicitation responses.
Federal Acquisition Regulation (FAR) Part 23.206 requires Federal agencies to insert the clause at FAR section 52.223-15 in solicitations and contracts that deliver, acquire, furnish, or specify energy-consuming products. FEMP recommends that agencies incorporate efficiency requirements into both the technical specification and evaluation sections of solicitations. Agencies may claim an exception to these requirements through a written finding that no ENERGY STAR–qualified or FEMP-designated product category is available to meet the functional requirements, or that no such product is life cycle cost-effective for the specific application. Additional information on Federal requirements is available.
Buying Energy-Efficient Fluorescent Ballasts
The Federal supply sources for energy-efficient fluorescent ballasts are the Defense Logistics Agency (DLA) and the General Services Administration (GSA). GSA offers them on Schedule 62-II, as well as through its on-line shopping network, GSA Advantage!
When contracting or buying from a commercial source, specify or select a ballast with a ballast efficacy factor that meets or exceeds those shown in the Efficiency Requirements tables for that lamp type, start type, and number of lamps.
Agencies must use ENERGY STAR–qualified and FEMP-designated efficiency requirements for all procurements of energy-consuming products and systems including guide and project specifications, and construction, renovation and service contracts. These efficiency requirements should also be used in evaluating responses to solicitations. In contracts and solicitations, agencies must specify that fluorescent ballasts meet or exceed the performance levels shown in the Efficiency Requirements tables.
Agencies can claim an exception to these requirements through a written finding that no ENERGY STAR–qualified or FEMP-designated product category is available to meet the functional requirements, or that no such product is life cycle cost-effective for the specific application.
Buyer Tips: How to Choose Efficient Products
Ballast efficacy factors should be readily available in manufacturers' literature. If they are not, ask your supplier for the data. If unavailable, ballast efficacy factors also can be calculated by dividing ballast factor by input watts, which are available on product specification sheets.
The most efficient ballasts for 4-foot T8, 32-watt lamps are "instant-start" ballasts, which may shorten lamp life in applications where lamps are turned on and off frequently; slightly less efficient "programmed rapid-start" ballasts are preferable in these applications.
While electronic dimming ballasts are exempt from these specifications, FEMP recommends that Federal purchasers consider the use of dimming ballasts for appropriate applications. Dimming ballasts with well-designed lighting controls can achieve large energy savings by moderating the timing and light output of lighting systems.
Fluorescent lamp ballasts should have a ballast factor between 85% and 105% in most applications to maximize light output, avoid reduced lamp life, and prevent unnecessary power consumption. Total harmonic distortion (THD) should be 20% or less, to reduce interference with electronic equipment. Current crest factor (CCF) should be 1.7 or less, to avoid reduced lamp life.
Total harmonic distortion (THD) measures the degree to which the current wave shape is distorted from a sinusoidal wave, expressed as a percentage. Current crest factor (CCF) is the ratio of the peak lamp current to the root mean squared (rms), or average, lamp current. CCF has a range of 1 and above.
For More Information
The following resources provide additional information surrounding the purchase of efficient products:
Lawrence Berkeley National Laboratory