Investigation of energy performance and climate change adaptation strategies of hotels in Greece

Abstract

There is evidence that hotels are the highest energy use buildings of the tertiary sector in Europe and internationally because of their operational characteristics and the large number of users. Therefore, there is potential for significant energy savings. This study investigated the energy performance of the hotel sector in Greece and proposes a methodology for their energy classification and climate change mitigation strategies for an optimum building envelope design for a typical hotel building operated all year or seasonally. This was achieved by collecting operational energy data for 90 Greek hotels and analyzing them using the k-means algorithm. Then a typical hotel building was modelled using TRNSYS and climate change weather files to assess the impact on its energy demand and to propose climate change mitigation strategies. The assessment was performed via hourly simulations with real climatic data for the past and generated future data for the years 2020, 2050 and 2080. The analysis of the energy data (based on utilities supply) of 90 hotels shows average consumption approx 290 kWh/m2/year for hotels with annual operation and 200 kWh/m2/year for hotels with seasonal operation. Furthermore, the hotels were classified in well separated clusters in terms of their electricity and oil consumption. The classification showed that each cluster has high average energy consumption compared to other buildings in Greece. Cooling energy demand of the typical building increased by 33% and heating energy demand decreased by 22% in 2010 compared to 1970. Cooling load is expected to rise by 15% in year 2020, 34% in year 2050 and 63% in year 2080 compared to year 1970. Heating load is expected to decrease by 14% in year 2020, 29% in year 2050 and 46% in year 2080. It was found that different strategies can be applied to all year and seasonally operated buildings for the most energy efficient performance. These include: a. For all year operated buildings: insulation, double low e glazing, intelligently controlled night and day ventilation, ceiling fans and shading. The building of year 2050 would need more shading and the building of year 2080 would need additional shading and cool materials. b. For seasonally operated buildings: Intelligently controlled night and day ventilation, cool materials, ceiling fans, shading and double low e glazing. Only the building of year 2080 would need insulation. This study makes a contribution to understanding the impact of the climate change on the energy demand of hotel buildings and proposes mitigation strategies that focus on the building envelope in different periods and climatic zones of Greece.