Congress, recognizing the potential for energy savings in the use of general lighting for illumination, requested in the Energy Independence and Security Act of 2007 (EISA 2007) that the Department of Energy (DOE) contract with the National Research Council (NRC) to conduct a study to assess the status of solid-state lighting (SSL) as a technology.The contract requested that the National Academies provide an objective and independent assessment of the current state of solid-state lighting and its future potential for accommodating the new minimum efficiency standards for lighting. The NRC established the Committee on Assessment of Solid State Lighting (Appendix A) composed of diverse experts in the fields of solid-state physics, electronics, lighting design, human perception of light, industrial commercialization, and policy. The statement of work directed the committee to review the development and future impacts of SSL, including projections of cost and research and development (R&D) necessary to overcome barriers to widespread adoption and the potential for unintended consequences of deployment. Solid-state lighting consists of two technologies—the inorganic semiconductor-based light-emitting diode (LED) and the organic polymeric-based light-emitting diode (OLED). Both technologies are the subject of active research worldwide. The LED technology is currently in the early stages of commercial deployment while OLEDs are in the demonstration phase. All LED-based luminaires require optics to distribute the unidirectional light emitted by the LED and a large heat sink to maintain the LED temperature within limits. Furthermore, like fluorescent lamps, both LED and OLEDs require they be supplied through an electronic circuit to provide them with the proper form of electric power. Both LEDs and OLEDs and the luminaires based on them are discussed below.