EDP NEW study on energy consumption and comfort in Portuguese residential pilot

Buildings are indispensable for meeting the EU’s carbon neutrality, energy efficiency and renewable energy objectives. The building stock is Europe's largest single energy consumer, accounting for 40% of the EU's energy consumption. In that perspective, EDP NEW, a SATO partner and leader of the demonstration activities, is developing a research study to promote energy efficiency in the residential building stock. The study is part of a dissertation for the Master Programme in Energy Engineering and Management at the University of Lisbon - Instituto Superior Técnico, titled “Monitoring of energy consumption profile and comfort conditions in residential buildings”.

The proposed work will evaluate the energy consumption and indoor comfort characteristics of households of the Portuguese residential pilot, located in the municipality of Seixal. Out of the 50 buildings in the pilot, 23 buildings were selected, after excluding buildings with missing or inaccurate information, but ensuring that the sample reflects a diverse, yet representative group of buildings. Data collected on building energy consumption over the course of a year will be thoroughly analysed and subjected to an initial pre-processing phase. Data cleaning strategies will be used during this step to verify the accuracy and reliability of the dataset.

The establishment of an annual Energy Use Intensity (EUI), expressed in kWh/m2, is a significant component of this research, providing a metric for quantifying and comparing building performance throughout the sample. At the EU level, the EUI for residential buildings is approximately 180 kWh/m2 [1], with considerable heterogeneity among member states. Portugal stands out with a notably lower EUI of 70 kWh/m2 [2]. This large gap difference can be explained by examining the breakdown of the household energy consumption by end-use. While, on average, space heating constitutes the largest share of household energy use in the EU, accounting for 62.9% of the total energy consumption, Portugal diverges significantly. The country's Mediterranean climate, characterized by dry, warm summers and mild, rainy winters, results in only 23.2% of energy consumption being allocated to space heating. This deviation highlights the climate's impact on residential energy needs, as Portugal requires less space heating compared to Nordic countries. Interestingly, the breakdown reveals a unique trend in Portugal, where kitchen appliances occupy a predominant position as the primary end-use, surpassing the European average (Figure 1a and 1b).

Figure 1a Figure 1b

Figure 1 - Residential energy consumption by final use in the EU (a) and Portugal (b) in 2020 [1, 2]

To allow for a more granular analysis, the EUI will be further analysed based on building typology, type of housing, and other parameter values that affect energy consumption, such as useful floor area, number of occupants, and the year of construction. The research continues to create typical load profiles for different periods, including typical weekdays, weekends, and seasons. These profiles provide a more in-depth insight into energy consumption trends, showing peak consumption periods and pilots suitable for targeted energy saving measures. Furthermore, the weighted contribution of different appliances to the overall energy consumption will be assessed.

The findings of the study provide valuable insights into the energy-related behaviour of Portuguese households and offer crucial guidance for improving energy efficiency and enhancing indoor comfort in residential settings. Finally, the outputs will be compared with European benchmarks.

Bibliography

[1] A. Gaglia, K. Tsikaloudaki, E. Dialynas and K. Laskos, “The Impact of the Energy Performance Regulations’ updated on the construction technology, economics and energy aspects of new residential buildings: The case of Greece,” Energy and Buildings, vol. 155, 2017.

[2] Buildings Performance Institute Europe (BPIE), “Factsheet: Portugal - Current use of EPCs and potential links to iBRoad,” 2018.