Once considered a “technology of the future”, light emitting diode (LED) lighting systems are becoming more common on Harvard’s campus. These fixtures and lamps are still not perfect for every application, but advances in lumen output per watt, reduced fixture prices, and strong incentives from NStar have combined to make LEDs increasingly attractive in both new construction and retrofit projects.

As a general rule, LEDs have higher initial costs but lower operating costs and longer life spans than conventional products. Unlike fluorescent and incandescent bulbs LEDs are a directional light source, and they perform best in applications such as recessed can down-lighting, track lighting, and parabolic aluminized reflector (PAR) style fixtures where light is focused in along a single path. While lumen per watt efficiencies are improving nearly every month, efficient low wattage T8 and T5 linear fluorescents still tend to outperform LED replacements in pendant lamp applications where multi-directional lighting is desired. At the same time, fluorescent lamp efficacies (how well the lamp produces visible light) are advancing far more slowly than LEDs, with multiple manufacturer representatives commenting to Green Building Services staff that they expect commercially available and economically competitive LED lamps to pass the 100 lumen/watt mark within the next three to five years. LED efficacy for products available today vary widely, with products on the MassSave Approved Product list ranging from 31 to over 92 lumens/watt.

Multiple departments on campus have already incorporated LED technology into their facilities. Dan Beaudoin, Operations Energy and Utilities Manager for the Harvard School of Public Health, began experimenting with various LED bulbs approximately three years ago, and early problems with the new technology have led him to refine his selection process. “I started by going online, buying cheap LED bulbs, and placing them in various locations to test them out. Many of those lamps are already failing.” Since then he has studied the technology in much more detail, and has had great success with higher quality Cree , Lunera, and CRS Electronics lamps that meet stringent performance standards developed by ANSI and IESNA. For those looking to begin installing LEDs in their departments he suggests starting “by educating yourself about testing standards and what they mean, and then partner with quality manufacturer representatives who are familiar with incentive requirements and applications to develop a pilot project.” He is now convinced enough of the value of the technology that both 90 Smith Street and the Kresge building are implementing 100% LED lighting, with anticipated NStar incentives covering over $175,000 of the initial costs.

The Faculty of Arts and Sciences have installed LED chandelier/candelabra bulbs in Dunster Dining Hall and Cabot House, and recessed can lamps in Adams House. Leverett and Quincy House have incorporated PAR38 equivalent replacements rated up to 45,000 hours as part of their exterior downlighting strategy. FAS is primarily installing Philips and GE products.

NStar offers sizable incentives for new and retrofit LED lamps, but only certain products are eligible due to the wide range of quality and efficiency that can be found within the LED family of products. Payments ranging from $15-$100 per fixture are available for can lights, track lights, refrigerator fixtures, and a wide range of exterior products, but only lamps on the MassSave list of approved products are eligible to apply for prescriptive incentives. After discovering that lamps that are being installed in Kresge were more efficient than those on the MassSave list, Beaudoin was able to work with NStar to earn incentives via custom applications.