Improving the quantification of building energy savings through temperature-sensitivity analysis

Buildings are responsible for a significant proportion of total energy consumption and therefore represent an important target for energy savings. Their consumption is strongly temperature-dependent, as it is dominated by the heating and cooling demand to ensure thermal comfort inside.

To quantify the energy savings of a building over time (for example after renovation or with lowered indoor temperatures), it is necessary to remove the influence of meteorology on energy consumption and determine the part that is independent of weather, i.e. related to the building properties and its use. Current methodologies use daily energy demand proxies (degree-days) with fixed temperature thresholds for heating and cooling. However, hourly energy consumption is increasingly monitored by smart meters, and high-quality meteorological reanalysis data are available globally, giving access to a finer temporal scale on which variations in both outside temperature and building use are expected.

Here we present a case study using 10 years of hourly meteorological data and energy consumption data from a university campus in Germany. We analyze the meteorology-dependent energy consumption including its sub-daily variations. We investigate the differences in energy savings quantification depending on the time step used. The detailed knowledge of energy consumption patterns and their temperature sensitivity that we obtain also provides the basis for identifying potential future energy savings through retrofits and changes in user behavior.