|Halogen Incandeso Price||LED||Summary|
|Lamp Type||Power (W)||price (incl. 7 percent sales tax)||Life (h)||Cost to Owna||10.000 hr Costb||Power (w)||price (incl. 7 percent sales tax)||Life (h)||Cost to Owna||10.000 hr Costb||Savings Over 10.000 his||Savings (%)||Initial Cost Ratio|
|T3||150||$4.42||2,000||$37.42||$187.10||not available||not appliesible|
aEnergy rate $0.11/kWh.
bNot including labor to install lamp(s).
$0.11/kWh, LED lamps save between 35 and 58 percent over 10,000 hours of operation, which corresponds to about 10 years in typical residential use. Table 4.1 summarizes the results of this survey. The LEDs that were chosen for this comparison are the closest available in light output to the halogen lamps that they would replace. The “cost to own” is the price of the lamp plus the energy cost over the lifetime of the lamp. This calculation is limited to 10,000 hours, even though most of the life ratings shown on the LED packaging are actually longer than that. The initial price ratio in the final column is just the ratio of the prices of one LED to one halogen lamp (measuring “sticker shock”) even though more than one halogen lamp needs to be purchased to reach 10,000 hours of use. Finally, it is also worth noting that LED alternatives are not available for all lamp types at this time, such as the T3 tubular lamp that is used for example in some bathroom vanity lights and floor lamps. A calculation of lifecycle costs of LEDs and various fluorescent lamps, taking account of discount factors and expected improvements in LED performance, is included in Chapter 6.
Purchasing a product while the technology is still evolving is always challenging, especially when the life of the product is very long. Having said that, people are now accustomed to upgrading computers and cell phones in 2 to 5 years because they see value in the new product’s functions. The same cannot be said for lighting. Until now, people have typically changed a light bulb only when the previous one has failed. Unless the payback period is very short, many would find it difficult to justify investing in LED lighting products as replacements for traditional light bulbs, as promoted by the SSL industry. As a result consumers take a “wait and see” approach, even though the currently available LED products could save them significant amounts of energy.
Nevertheless, SSL offers new methods to light our spaces. SSL technologies can be embedded into many types of architectural elements due to their small size and long life to meet the needs of desired tasks or ambiance for the occupant. Responding to this opportunity, researchers and industry groups have been attracted to the concept of creating mini direct current (dc) grids within buildings for lighting and some appliances (as well as power production from photovoltaic systems) while maintaining an alternating current (ac) power grid to transmit power from the generation site to end-user sites without much loss (EMerge Alliance, 2012; Narendran, 2012; Thomas et al., 2012).
A dc-powered SSL infrastructure that allows for rapid reconfigurations of lighting systems using LED-lighted panels that snap in and out of a modular electrical grid, makes it as easy to redesign lighting as to move furniture, providing value to the end users. Such concepts not only allow for greater energy savings, but also can improve lighting in our built environments.
FINDING: The power requirements and flexible physical configurations of SSL make attractive the concept of a new dc building lighting infrastructure.
RECOMMENDATION 4-6: The SSL industry should collaborate with other industries such as building materials and construction to explore the challenges and potential benefits of developing and adopting standards for a new dc electrical infrastructure.
Acikalin, T., S.V. Garimella, A. Raman, and J. Petrosk. 2007. Characterization and optimization of the thermal performance of miniature piezoelectric fans. International Journal of Heat and Fluid Flow 28(4):806-820.
Davis, J.L. 2012. Building a System Reliability Model for SSL Luminaires. Paper presented at The Seventh Annual DOE Solid-State Lighting Market Introduction Workshop, Pittsburgh, Pa., July 17-19.
DOE (U.S. Department of Energy). 2012. CALiPER Program. Available at http://www1.eere.energy.gov/buildings/ssl/caliper.html. Accessed August 2, 2012.