E NERGY SIMULATION OF BUILDINGS TYPOLOGIES AND THERMAL COMFORT

The combination with survey data has proved effective to characterize the two groups of interest for the analysis in this paper. The socio-economic data combined with the annual consumption profiles uncovers potential lack of thermal comfort levels inside households both in summer and winter for the FP consumer group, but it is not clear for the FO group and needs further enlightenment. The high levels of daily electricity consumption (over 40 kWh/day) together with its descriptive socio-economic variables could indicate fuel obesity patterns. Yet, when looking deeper in the two distinct annual consumption profiles, different conclusions might be drawn. In a region with very hot summers (average temperature around 23ºC) that might require high cooling demand, substantial differences in summer and winter months’ electricity consumption might suggest lack of thermal comfort levels, in summer months.

3.1.3.2 Energy simulation of buildings typologies and thermal comfort

increase due to climate change, as the case study. We conclude that fuel poverty is prevalent amongst the households in this group though a detailed appraisal of individual households could suggest that not all households might be under fuel poverty in equal measure.

Figure 3.4 – Heating and cooling annual energy demand for the typologies of the two consumer groups: fuel poverty (top) and fuel obesity (bottom)

In the case of the potential fuel obesity group, and contrary to what could be expected from the annual consumption profiles and socio-economic determinants, the thermal comfort performance gap appears still very high. Despite the levels of consumption in this group are around sevenfold the other consumers group, the calculated gap is 94% for space heating and 87% for space cooling, still high values and close to the other group. This is due to the similar average demand for space heating and cooling between the two groups, but bigger households in the FO group. Real measured consumption is still far from fully satisfaction of “ideal” indoor thermal comfort levels and was also revealed by the substantially lower consumption in summer identified in the annual consumption profiles. But these conclusions can only be straightforward applied to the cooling season, since we are assessing just electricity for climatization. For space

heating, in households with both electric and non-electric climatization, the use of e.g.

fireplaces, may partly bridge this gap, presenting this estimations as conservative. Nonetheless, these performance gaps are aligned with the results from Palma (2017), where a widespread lack of thermal comfort across the majority of Portuguese civil parishes was assessed (i.e.

88.2% gap for space heating and 94% for space cooling in the city of Évora), under less conservative schedules and household conditioned areas.

The thermal comfort performance gaps for both groups allow to derive some important conclusions for this region and sample. The results stress the importance of addressing the fuel poverty problem and the need for increased awareness and policy support. From the surveys, we identified the ownership of both space cooling and heating equipment, but these results clearly show that having the equipment does not mean it is used. This can be partly justified by the high costs of energy for families, as stated in Section 1, when compared to EU28 average. According to IEA (2016), electricity prices in Portugal are relatively high by IEA standards and they have been increasing significantly over the past decade. From 2008 to 2013, final electricity prices increased annually on average by 8.8% for household customer.

Figure 3.5 – Heating and cooling thermal performance gaps for both consumer groups

Another important outcome from the results is the significance of behavior and of socio- economic details (as income). Therefore, income is a relevant determinant that explains the consumption differences from both groups. Seebauer and Wold (2017) identify the influence of income on electricity consumption, highlighting that instead of influencing daily electricity consuming routines, the income level could drive appliance purchases, setting a household’s

base electricity load, which is also aligned with the idea of bringing for discussion the fuel obesity group.

Energy prices and a general low ownership of cooling equipment in the city (and country) partly explain the high thermal performance gap for both consumer groups in the cooling season.

However, in Portugal, as other Mediterranean countries, the use of traditional cooling techniques (opening windows during the night, shading device) are very common, allowing the occupants to minimize higher indoor temperatures. We argue that these cultural habits partly explain the high values of thermal comfort gaps, also in the Fuel Obesity group. Further analysis should be carried, for example based on direct inquiries of the occupants on their thermal comfort, instead of assessing it through energy consumption analysis.

We acknowledge some boundaries to our performance gaps results derived from the assumptions used, as follows: a) despite supported by information of ownership and use of other energy sources from the door to door surveys, our methodology only address electricity consumption, b) we assume average equipment efficiencies for the conversion of energy services calculated from the simulations to final energy demand; and c) due to lack of local information, we use national indicators on the electricity consumption used for heating and cooling.

However, despite these limitations, we were able to draw important conclusions on consumer segmentation groups, deepening the understanding on consumers under fuel poverty conditions and the main drivers for that. But it becomes evident that our first perception in defining the second group of consumers, as a fuel obesity group, based on the electricity consumption levels, can be understood as panglossian after an accurate analysis of the actual thermal comfort gaps.

This raises the importance of combined assessments supported by multiple datasets for robust conclusions.

Therefore, despite the differences in electricity consumption patterns, both consumer groups still need to increase their consumption to achieve a better indoor comfort and reduce related health problems. To overcome this thermal comfort gap, a strong increase in energy consumption should be expected, which will affect the EU policy goals on energy consumption and emissions reduction. Therefore, we consider of utmost importance that tailor-made policies and information campaigns addressing (i) high-income households should focus on support increased use of more efficient equipment, lifestyle changes and adoption of renewable energy sources, and (ii) low-income households should focus on incentives either for efficient equipment or renewables use, or either to burden energy costs. Energy policies and measures can help to tackle the expected energy consumption in the future, but with clear differences on how to approach and target each consumer groups.

In Portugal, energy subsidies (named as social tariff) have been provided for the fuel poor households minimizing the high-energy costs but they do not provide a sustainable long-term solution not addressing the root causes of the problem. On the opposite, energy renovation measures of households at fuel poverty risk can give a long-term sustainable answer improving the energy performance of buildings. These solutions can compete with higher energy consumption from e.g. heaters and air conditioners in providing space heating and cooling services demand. Though, while insulation measures can be used as a protective measure in buildings, insulation by the interior increases the risk of overheating. Note that in a country like Portugal and at Évora specifically, some measures, such as external insulation, might cause much more thermal discomfort in the summer worsening the problem.

Modernization and retrofit of buildings and energy equipment is therefore an effective solution for energy poor households as presented by Bouzarovski and Petrova (2015), but identifying and funding those households might be an issue, even in high income countries, with the ability for extensive data collection. Our methodology presents an alternative approach for such identification.

Another alternative solution to overcome the thermal comfort gap is the increase of use of locally produced electricity from renewable sources. Évora has a high solar PV rooftop potential (40MW) (Moreira, 2016). Therefore, this strategy could be very important to help increase thermal comfort levels without an increase in energy costs to both groups of consumers. Also, green and cool roofs, smart glazing, thermochromics materials inducing changes in the color of the building’s façade that reduce heating and cooling needs are solutions that will overcome the thermal comfort needs without increasing energy consumption.