Review of heating and cooling technologies for buildings: A techno-economic case study of eleven European countries

The present study develops a review of heating and cooling (H&C) technologies used to produce space H&C services in eleven European member states. On the one hand, it revises (a) technical parameters, e.g. energy efficiency, of various H&C technologies. On the other hand, it reflects the status-quo of (b) economic costs of these systems, and it exhibits a (c) short environmental impact assessment. Costs are differentiated between investment and operational costs. The H&C technology portfolio is subdivided into (i) end-use heating technologies, (ii) district heating (DH) technologies and (iii) cooling technologies. Based on the data analysis, the different H&C systems are compared among one another in terms of technical efficiency, capital and operational cost, and technical lifetime and age of the technology stock. Whilst the different heat pump (HP) systems excel in the average efficiency, natural gas boilers are the most efficient option among fossil fuel fired boilers. Furthermore, it is the cleanest of the fossil fuels. The environmental assessment exhibits the importance of renewable energy systems for a sustainable energy transition. HP systems and electric heaters are grid -dependent and the CO2 footprint depends on the carbon footprint of the specific country's electricity supply. Regarding the economic analysis, following is concluded: on average, the capital costs of end-use HPs and solar thermal collectors are around 1000 ke/MW, while biomass boilers cost slightly more. Both on a DH and end-use level, fossil fuel boilers are among the most cost-efficient options. District cooling systems are low-cost options compared to small granular air-conditioners. Furthermore, HP systems (which can provide heating and cooling attendances) are more cost-effective on a decentralised scale, meanwhile biomass boilers and combined heat and power (CHP) plants are more cost competitive on a large DH plant level. Current developments and challenges within the residential sector are identified and future research trends are summarised. Overall, the outcome is a simple, but unified review of heating and cooling technologies for Europe and a perspective for efficient pathways for this sector.