Let there be (greener) light.

• Position: Conservation - Brief article

Parking lots and garages light up the night--daytime users drive home and nighttime users are few but, for safety reasons, the lights stay on. Michael Siminovitch, director of the Lighting Technology Center at the University of California, Davis, and a professor in the Design Program, says seeing all that wasted light "makes you jump out of your seat and say 'Stop!' "--and that is what Siminovitch has done. The result is a highly efficient and innovative package of technologies using about 20% of the energy of conventional parking lighting systems, yet providing better safety, reducing light pollution, and producing less toxic waste.

The new system includes:

* Light-emitting diodes, which give off bright white light but use little electricity. Each fixture, called a luminaire, has three light bars containing 60 LEDs. Compared to conventional metal-halide lights, LEDs take less electricity (85 watts vs. 175 watts), last longer, and contain no mercury.

* Motion sensors, which detect the movement of a...