Sustainability

Solid state lighting reduces energy consumption

A world-wide revolution in lighting technology is coming, led by the rapid development of highly efficient LED bulbs and lighting fixtures. LED lighting (or solid state lighting, because semiconductor devices are generating the light) can now produce high quality light for almost any application, offering large reductions in electrical energy consumption and lifetimes 10 to 20 times longer than conventional bulbs and tubes. You don’t see them too much on campus because this sustainable, energy saving technology is new and still expensive—but the newly formed Smart Lighting Engineering Research Center Sustainability Club, working with the National Science Foundation-funded Smart Lighting ERC and Rensselaer Facilities Management, aims to make LED lighting on campus a key part of Rensselaer’s electrical energy reduction efforts. This is important, because lighting is responsible for 20-40 percent of the total electrical energy used on campus.

This past spring and summer, the group kicked off its first campus project, bulb replacement in the Great Hall and second floor of the Darrin Communications Center. The purpose of this project is to replace approximately 300 75W PAR30 halogen bulbs in the DCC operating 24/7 with 15 W LED bulbs giving equivalent or better light quality with significantly longer lifetimes (estimated at 6 years compared to less than 6 months for the inefficient incandescent bulbs). Initial energy savings are projected to be 80 percent, which puts the return on investment for the project at a mere 18 months.

Volunteer group activities started with a LED bulb demo and bulb preference vote led in the spring semster by the Sustainability Cases Senior Capstone team from the Multidisciplinary Design Lab. During the summer, a dedicated group of student volunteers both on campus and working remotely, made great headway with the DCC project. This included a DCC lighting infrastructure review with Rensselaer Facilities, a specification review and test of commercially available LED bulbs, a review and specification of energy monitoring instrumentation for tracking energy savings, modeling the physical space and illumination fields (illuminance) to optimize bulb selection, and initial research of daylighting control options which would further improve the energy savings by dimming the lights near the windows on sunny days. The summer effort concluded with the final specification of the energy monitoring equipment and replacement LED light bulbs, which have just been ordered.

This fall, the group will be busy coordinating and implementing the DCC bulb retrofit and energy monitoring instrumentation with the Facilities team, assembling demonstration solid state lighting units, educating the Rensselaer community on the many benefits of solid state lighting, and exploring opportunities for additional projects on campus. Additional projects will seek to extend the advanced research of the Smart Lighting ERC to add new capabilities to the LED lighting installations on campus. While the LED bulb replacement effort on campus is a critical first wave in the coming solid state lighting revolution, the ERC is exploring even higher efficiency lighting solutions that can also communicate high speed data, know exactly when to be on or off, and even adapt autonomously to changing lighting needs for work, better health, entertainment or relaxation. This will be the second wave of the solid state lighting revolution that will forever change how people interact with and benefit from solid state illumination systems.

You can keep up with both the first wave LED bulb retrofit projects and new second wave advanced lighting systems research developments on the Smart Lighting ERC website (http://smartlighting.rpi.edu/). If you are interested in joining this worthwhile effort the Smart Lighting ERC Sustainability Club is undertaking, please contact us through the link on our website.