The aim of this study is to investigate, review, and assess the recent advances of alternative cooling technologies using traditional vapor compression (VC) systems as a baseline. Around 99% of the final energy consumption used for cooling in the current European market (European Union plus the United Kingdom (EU27 + UK) is supplied by VC technologies. In comparison, the remaining 1% is produced by thermally driven heat pumps (TDHPs). This study focuses on providing a complete taxonomy of cooling technologies. While the EU heating sector is broadly explored in scientific literature, a significant lack of data and information is present in the cooling sector. This study highlights technologies that can potentially compete and eventually replace VC systems within the decade (2030). Among others, the most promising of these are membrane heat pump, transcritical cycle, Reverse Brayton (Bell Coleman cycle), and absorption cooling. However, the latter mentioned technologies still need further research and development (R&D) to become fully competitive with VC technologies. Notably, there are no alternative cooling technologies characterized by higher efficiency and less cost than VC technologies in the EU market.

Greenhouse gas emissions have reached critical levels and climate change is threatening the globe. Thus, the space heating and cooling sector is striving to decarbonize assets through higher efficiency and renewable energy adoption for 2030 and 2050. This article reviewed data about the environmental impact and the primary energy consumption of 27 space heating and cooling technologies for the residential sector as if they were adopted in 11 different European member states: Austria, Cyprus, Denmark, Estonia, France, Germany, Italy, Poland, Romania, Spain, and Sweden. Direct emissions from the machineries and upstream indirect emissions from the energy carriers were considered. The analysis indicates that the adoption of renewable energy-powered technologies should be prioritized due to the significantly lower emissions related to these technologies. Notably, the emissions of electricity-powered technologies, if not driven by the direct self-consumption of renewable energy systems, highly depend on the region of adoption: in specific cases, such as in Poland, Cyprus, and Estonia, they can even exceed the emissions of coal-powered technologies. These countries should speed up the adoption of decarbonization policies regarding the residential sector to close the gap with the other EU member states and provide their contribution to the EU climate change goals.

Reducing greenhouse gas (GHG) emissions and energy consumption in the building sector requires not only improving the energy efficiency of buildings but also minimising material requirements, embodied emissions, and waste generation. Circular Economy (CE) principles can be applied to minimize resource extraction and waste generation in the building industry. However, to implement effective CE strategies, quantification and evaluation of materials accumulated in buildings are required. This study aims to provide accurate data and a detailed analysis of the materials available in the EU27 residential building sector. By elaborating the data provided by the H2020 European projects Hotmaps and AmBIENCe, the different materials used for floors, roofs, walls, windows, and insulation layers in single-family houses, multifamily houses, and apartment blocks in the different construction periods were quantified for each EU27 country. Considering results at the EU27 level, concrete and brick characterize the largest part of the European residential building stock, whereas materials such as wood and different types of rock are used in much more limited amounts. These results form the basis for policymakers to monitor the status of the residential building sector, evaluate the potential of CE policies at a national level, and assess the environmental impact of building practices through lifecycle assessment.

The European Union recognizes the vital role that innovation in renewable energy technologies plays in accelerating the energy transition. In the largest ever transnational research and innovation program, Horizon Europe (2021–2027), the EU allocated 35% of the total budget of €95.5 billion to green technology research. This paper examines public research and development (R&D) funding for renewable energy technologies in 17 European countries from 2000 to 2020 by analyzing its extent, composition, and effectiveness. While large economies lead in the size of total available public R&D support, Nordic countries lead when it comes to available public R&D funding relative to the sizes of their respective economies. Thereby, the share of the European Union’s funding within the total public R&D support available in each country is vastly heterogeneous across countries, ranging from 13% to 63%. Furthermore, based on detailed and recent data, the effectiveness of public R&D funding is estimated through a Negative Binomial Regression model with fixed effects. Overall, public R&D funding is confirmed as an effective driver of green innovation. Like in previous studies, limitations stem from restricted data availability and temporal uncertainty of innovation. These limitations are addressed, which shall incentivize future research and policymaking.

A lack of aggregate analysis concerning energy communities exists in the academic literature. The authors utilized a combination of literature reviews and desk research to fill this gap. The existing debate on the classification of energy communities was summarized and aligned. Discovered classifications were used to analyze the status quo of the sector. The authors found nearly 4000 energy communities with 900,000 members in the European Union. On average, there are 844 members per one energy community. Germany, the Netherlands, Denmark, and the United Kingdom are at the forefront of the movement. Different countries have different primary sources of renewable energy utilized by energy communities, and membership structures vary based on the energy source and corporate purpose of the energy community together with the sector’s maturity in a certain country. Predominantly, hydro and biomass are used by energy communities in Alpine countries, solar energy is used in Germany, Spain, and France, wind in the Netherlands and Denmark, and different renewables in the United Kingdom. More members have joined the hydro, biomass, and wind communities than solar communities. Each country has national and regional associations of energy communities. In addition, intermediary actors, researchers, and consultancy agencies have shown a growing interest in the deployment of the movement. Achieving a conformity of business models Europe-wide would probably be impossible and pointless. Distinct geographical, institutional, and policy context-specific conditions stimulate diversity rather than conformity.