Traditional overhead lighting approaches for commercial office spaces have serious drawbacks both in terms of energy efficiency and lighting quality. These systems uniformly place high levels of illuminance throughout the space not only wasting energy by putting light where it is not needed, but often times actually hindering visibility in the workspace by presenting high levels of glare and lowering contrast on VDTs.

The combination of low-level ambient lighting (for general office circulation, etc.) with targeted, high-output task light has been shown to be useful in increasing energy efficiency and lighting quality in office spaces. Furthermore, studies with the Berkeley Lamp, a self-contained and portable task-ambient luminaire, have found that giving the user greater control over the placement and control of their lighting systems further benefits the energy efficiency and lighting quality of the office.

The current state of the technologies to be developed within this project is embodied in the Berkeley Lamp. The Berkeley Lamp is a portable lamp that can be placed in an individual's workspace to give them discrete control over their task and ambient lighting environment. Currently, the Berkeley Lamp can be plugged into a simplified occupancy control system. It is planned to expand the control capabilities and integrate it into an office lighting system that turns lights off when the workspace is vacant.

The Berkeley Lamp has been very successful in improving the visibility and energy efficiency in office spaces largely because it gives the users more control over their lighting environment than they previously had. But the Berkeley Lamp was not designed with medium to large office environments in mind and consequently has some limitation when applied in these situations.

The current state of the market in commercial office spaces is dominated by ceiling mounted fluorescent luminaires that are generally designed and installed to uniformly illuminate the office space at relatively high levels (> 50 foot-candles). These systems can be direct (downlight), indirect, or some combination of the two. They generally employ linear fluorescent bulbs (T8s or T12) and either electronic or magnetic ballasts. One of the most significant issues observed with the Berkeley Lamp was that lighting controls (both automatic and user driven) could make significant inroads into conventional office lighting applications.

Participants in the Berkeley Lamp study revealed that further savings and user acceptance might be achieved if the lighting system is directly integrated to a controls system on a one-to-one basis with each occupant/user.