In just a few years, solid-state lighting has breached barriers of performance and cost effectiveness established by conventional technologies at the end of their evolutionary cycles. While fluorescent, incandescent (including halogen), and high intensity discharge sources are certain to improve, the improvements will be incremental.
LEDs, on the other hand, have already eclipsed incandescent sources, and when fixture performance is considered, are powering past compact fluorescent in real world applications today. With their long service life, compact size, and far greater directional control (meaning high application efficiencies), LED technology produces a unique opportunity to re-think many of the old paradigms of lighting system design. As the performance of LEDs continues its rapid expansion, and the cost of light delivered continues to drop, the obvious choice in general illumination will inevitably point toward solid-state illumination.