Evaluation of Light-Emitting Diode Lamps: A Report to the City of Albuquerque

摘要

Sandia assessed white LED lamps for parking lot, security and bike path lighting for the City of Albuquerque. Powering these lamps with photovoltaics was of particular interest to the city. Eight commercially available lamps were tested; one was AC and all others were 12-volt DC. Because DC-only photovoltaic systems do not regulate output voltage, a 12-volt nominal photovoltaic system can see a voltage range from 10.5-15.3 volts. Therefore, the LED lamp must be specified for the DC voltage range expected with a photovoltaic system. We found several failed lamps at the high voltage range of our test, which is below voltages that can be seen in the field. In addition, LED lamps need to be more powerful and cost competitive, and temperature and lifetime issues need to be addressed in order to be more widely useful with photovoltaic systems for illumination applications. We concluded that presently available white LED lighting powered by photovoltaics could be considered for bike path lighting applications where the area is remote, or for security lighting in areas that are difficult to access. We do not recommend LED lamps for much larger flux levels such as parking lot lighting at this time.