UC Berkeley LED Microscope Retrofits
The Molecular Imaging Center (MIC) at UC Berkeley is a state-of-the-art microscopy facility that is a collaboration of the school’s Cancer Research Laboratory, the Helen Wills Neuroscience Institute, and the Department of Molecular and Cell Biology. The facility serves the entire campus, supporting over 400 users each semester, and offering access to a wide range of advanced microscopy equipment useful in research and student coursework related to biology, chemistry, physics and material science. In 2015, a team of students conducted a creative pilot installation of LED microscope lights that offer cost savings and maintenance benefits, with improved convenience for lab users.
Led and funded by students, this project demonstrated the benefits of LED microscopy lights in terms of lower energy and maintenance costs, and better performance and safety for laboratory users.
Advanced laboratory microscopes such as those at the MIC typically use high-intensity discharge (HID) metal halide lamps to illuminate samples, however these present several problems for users and the environment. The lamps are slow to warm up, making intermittent use difficult, and users simply leave lamps on to avoid delaying subsequent users. The bulbs produce significant heat, which can interfere with samples, and may require separately powered fans for cooling. The lamps have a limited life span of approximately 2,000 hours, equivalent to about one year of average use, and the luminosity decreases over time. Finally, the lamps contain toxic mercury, and therefore require special disposal methods after use, and if broken may expose users to mercury or cause injury.
An LED lamp as installed on a Zeiss AxioImager research microscope.
However light emitting diode (LED) lamps are now available that eliminate many of these problems. They require little maintenance and have a life of over 25,000 hours, equivalent to twelve times that of metal halide lamps. They operate at cool temperatures, do not degrade over time, and contain no mercury.
A team of UC Berkeley students won an award of $25,000 from The Green Initiative Fund (TGIF), to purchase and install X-Cite 120LED lights in four MIC microscopes. As part of the project, the team monitored the energy consumption and usage of the lamps, conducted an awareness campaign for lab users to encourage energy saving practices, and worked to increase awareness of LED products throughout the Berkeley campus and at the Lawrence Berkeley National Laboratory.
Microscopy image of a mouse brain tissue section, by Helen Bateup, professor of neurobiology.
Although the LED lamps are significantly more expensive — approximately $5000 compared to $1200 for metal halides — their longer lamp life alone makes them cost effective. Over the 12-year life of a single LED lamp, a lab would need to purchase 12 metal halide lamps at a total cost of over $14,000. The simple payback on the lamps is approximately four years. In addition, less frequent replacements reduce maintenance, and energy savings produce additional savings. The student team monitored the usage statistics from the past 6-12 months to calculate energy savings, and estimated that the 14-watt LEDs use approximately 0.14 kWh per day, compared to the 4.7 kWh for the 151-watt metal halide lamps. They predicted annual electrical savings of approximately $175, or $2100 over the life of the lamps.
While the cost savings from the LED lighting is compelling, the students were surprised to find that campus laboratories frequently lack incentives and funding to make investments in energy efficient equipment. However, since this project was completed, the team has received positive feedback on their work, and several labs on campus have been motivated to purchase similar products. The students plan to seek a grant to complete additional upgrades at the MIC, and are investigating procurement and funding options that would enable the purchase of LED lamps broadly across campus.
Images courtesy of the UC Berkeley Molecular Imaging Center.