Natural light has a positive effect on human health. But skylights-our go-to source for delivering sunlight indoors-transmit heat, taxing your A/C system. Sunlight Direct (sunlight-direct.com) is testing a smarter approach: hybrid solar lighting (HSL). HSL captures direct sunlight while excluding heat-saturated infrared rays and uses optical fibers to channel it to indoor fixtures. On a sunny day, this system can transmit 50,000 lumens, enough to illuminate 1,000 square feet. Beta installations began in May at the American Museum of Science and Energy in Tennessee. Coming to a ceiling near you, for $8,000, by 2007.