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 – 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.

Reaching climate neutrality by 2050 is one of the main long-term objectives of the European Union climate and energy policy, and renewable energy sources (RES) are integral parts of this transition. RES development results in many effects, direct and indirect, linked to each other, societal, local and individual, i.e., “multiple impacts of RES” (MI RES). These effects need to be carefully assessed and evaluated to obtain the full picture of energy field transformation and its context, and enable further development of RES. Nevertheless, the MI RES concept is often presented misleadingly and its scope varies throughout the literature. This paper provides a literature overview of the methodologies of this concept and presents a new concept of MI RES, respecting the difference between effects resulting from the implementation of RES and ultimate multiple impacts. We have summarized the effects into four groups: economic, social, environmental, and technical, which all lead to group of ultimate multiple impacts. Finally, we provide the complex overview of all MI RES and present the framework, which is used to analyze the multiple impacts and effects of RES and to show how the RES development leads and contributes to these impacts and effects. The concept is recommended to be considered in designing a robust energy policy by decision-makers.

Renewable energy communities (RECs) are becoming a valuable concept for the energy transition, allowing citizens and local actors to participate in energy production and sharing. The paper examines the key motivations that impact the willingness of two specific actor groups, multi-apartment building representatives and municipal actors, to participate in or establish RECs, and how these motivations differ across the two actor types. Using a mixed-methods approach combining 50 in-depth interviews and 132 survey responses from Czechia, we identify and compare the relative importance of economic, environmental, technical, and societal motivations across these groups.Economic motivations, particularly energy cost savings and investment returns, are the dominant drivers for both actor types. Municipalities also place significantly more emphasis on energy security and autonomy, while representatives of multi-apartment buildings view RECs primarily as investment projects with limited community engagement. Environmental concerns are acknowledged, but often secondary, and societal benefits such as community cohesion or local employment are generally perceived as less influential.The findings contribute to a deeper understanding of the motivations that drive actors to enter and engage in RECs. The results also suggest that effective policies should be tailored to the needs of each group: community outreach and strategic planning for municipalities, as well as clear financial incentives and a straightforward regulatory framework for multi-apartment buildings.