||Solid-State Lighting (SSL) is a fast evolving, promising energy-efficient technology, offering a wide range of potential uses. The article presents the status of the existing light emitting diode (LED) pilot actions in Europe, analyzing 106 LED test cases from 17 European countries. Projects from the public and commercial sectors form the focus of this article, with special attention devoted to the economics of LED projects â particularly in terms of energy savings. The results of the test cases demonstrate wide variation. Installations offer energy savings of 59% on average (savings range from 10% to more than 90%). In many applications, LEDs are competitive (with payback time ranging from two to 10 years), yet a large number of projects are still in the trial phase. From the test cases reviewed, the most successful applications are, in terms of savings and economic considerations, replacement of both (1) incandescent light bulbs in traffic light systems, and (2) halogen spotlights in indoor applications. The LED projects bring many co-benefits, including lower maintenance costs, improved lighting characteristics, or improved ambience. Some challenges remain to be addressed, such as to improve the quality characteristics of LEDs and the quality of information and data provided by manufacturers/suppliers, and optimality of LED technology for existing street lighting systems.