With growing urban populations, methods of reducing the urban heat island effect have become increasingly important. Cool pavements altering the heat storage of materials used in pavements can lead to lower surface temperatures and reduce the thermal radiation emitted to the atmosphere. Cool pavement technologies utilize various strategies to reduce the temperature of new and existing pavements, including increased albedo, evaporative cooling, and reduced heat conduction. This process of negative radiation forces helps offset the impacts of increasing atmospheric temperatures. This paper presents an extensive analysis of the state of the art of cool pavements. The properties and principles of cool pavements are reviewed, including reflectivity, thermal emittance, heat transfer, thermal capacity, and permeability. The different types, research directions, and applications of reflective pavements are outlined and discussed. Maintenance and restoration technologies of cool pavements are reviewed, including permeable pavements. Results show that cool pavements have significant temperature reduction potential in the urban environment. This research is important for policy actions of the European Union, noting that European and international business stakeholders have recently expressed their interest in new ways of reducing energy consumption through technologically advanced pavements.

The paper presents a holistic evaluation of the energy and environmental profile of two renewable energy technologies: Photovoltaics (thin-film and crystalline) and solar thermal collectors (flat plate and vacuum tube). The selected renewable systems exhibit size scalability (i.e., photovoltaics can vary from small to large scale applications) and can easily fit to residential applications (i.e., solar thermal systems). Various technical variations were considered for each of the studied technologies. The environmental implications were assessed through detailed life cycle assessment (LCA), implemented from raw material extraction through manufacture, use, and end of life of the selected energy systems. The methodological order followed comprises two steps: i. LCA and uncertainty analysis (conducted via SimaPro), and ii. techno-economic assessment (conducted via RETScreen). All studied technologies exhibit environmental impacts during their production phase and through their operation they manage to mitigate significant amounts of emitted greenhouse gases due to the avoided use of fossil fuels. The life cycle carbon footprint was calculated for the studied solar systems and was compared to other energy production technologies (either renewables or fossil-fuel based) and the results fall within the range defined by the global literature. The study showed that the implementation of photovoltaics and solar thermal projects in areas with high average insolation (i.e., Crete, Southern Greece) can be financially viable even in the case of low feed-in-tariffs. The results of the combined evaluation provide insight on choosing the most appropriate technologies from multiple perspectives, including financial and environmental.

This paper introduces a methodology for the characterization of ports, employing specifically defined eco-efficiency indicators and combining typically available data (handled cargo, containers and passengers) with ship exhaust pollutants values (mainly NO_x, SO_x and PM) and anticipated external costs (ECs) due to emitted air pollutants to provide a collective overview of all port-related economic and environmental activities. The results from an applied case study allow a comparative evaluation of 16 selected ports based on 17 different evaluation criteria and denote that the employment of such an overall approach can allow port authorities to improve managerial aspects, potentially lower operational costs and promote reduced environmental effects.

In these days of heightened environmental consciousness, many countries are shifting their focus towards renewable energy sources for both large-scale uses (such as power plants that generate electricity) and smaller-scale applications (e.g., building heating and cooling). In this light, it is not surprising that there is a growing interest in technologies that are reliant on non-conventional sources of power, such as geothermal energy. This study is making an effort to provide a comprehensive understanding of the possible advantages and multiple uses of geothermal energy systems, in the context of their technical and environmental evaluation through Life Cycle Assessment. A brief description of the analyzing methods and the tools used to study a particular system or application is presented. The geothermal technologies and the applications of specific systems are discussed in detail, providing their environmental advantages and their technical barriers as well. District and domestic heating systems cover a significant fraction of the geothermal energy potential. The majority of the discussed studies cover the electricity production as the most important application of geothermal energy. The overall conclusion of the current work is that geothermal energy is an extremely viable alternative that, combined with other renewable energy systems, may mitigate the negative effects of the existing energy mix worldwide.