Impact of climate change on thermal comfort, heating and cooling energy demand in Europe

Bernard Aebischer, Martin Jakob, and Giacomo Catenazzi, ETH Zurich, Centre for Energy Policy and Economics (CEPE)
The late George Henderson

Keywords

climate change, energy demand, cooling, heating, energy efficiency, thermal comfort, overheating, energy policy

Abstract

So far, in most European countries, the amount of energy required for heating is greater by far than the energy used for space cooling on a national basis– even in the service sector. But due to higher internal loads, the proliferation of fashionable glass facades, thermal insulation, and rising standards of comfort, the cooled floor area is steadily increasing. Events like the extraordinary hot summer of 2003 are accelerating this trend and steadily rising mean annual temperatures (1.3°C during the 20th century in Switzerland) are increasing the specific energy demand for space cooling. In this paper, we provide evidence regarding the increasing relevance of thermal discomfort in terms of overheating, due to both building retrofits and climate change. Further, possible changes in heating and cooling energy demand over the next 30 years are explored for two climate variants: mean annual temperatures remaining constant and a second case in which temperatures increase until 2035 by +1°C in winter and +2°C in summer. The possible impacts on the CO2 emissions in different European locations are evaluated considering the CO2 intensity of the heating fuels, the market penetration of electric heating, and the CO2 intensity of electricity production.

For much of Europe, increases in cooling energy demand due to global warming will be outweighed by reductions in the need for heating energy. Depending on the generation mix in particular countries, the net effect on CO2 emissions may be an increase even where overall demand for delivered energy is reduced. Strategies and measures in the building sector to minimize possible negative impacts of climate change on energy demand for heating and cooling are discussed.