Energy Efficiency in Residential Buildings in Mozambique - Measurements and Simulations

University dissertation from Division of Building Science, Lund University

Abstract: Popular Abstract in English Energy savings and climate change mitigation have been discussed in the world since the oil crisis in the 1970s and the building sector has been seen as one of the largest contributors to global warming effects in the world. Energy efficiency in buildings is a critical issue to be addressed in order to reduce electricity energy used in buildings and is one of the main tasks that is developed within the program Advancing Sustainable Construction in Mozambique. The work done in this thesis contributes to better knowledge in the field of building energy performance through energy analysis, auditing, modelling, and simulations of energy use in buildings with a focus on the residential sector in Mozambique. Research in the energy efficiency in buildings sector is an important issue, because it can generate knowledge and awareness among builders, architects and engineers about the benefits of using tools which predict the energy use in buildings during the design stage or when retrofitting. It was found that there is a lack of suitable tools in Mozambique, for assessing building energy use during the design stage and at renewal. It was also found that the energy in residential buildings is used inefficiently. In order to find tools to cope with these problems, seven modelling and simulation tools were studied and among them one was selected as suitable to be used in Mozambique, considering factors as climate, building stock and education level. Additionally, measurement equipment for measuring indoor temperature, humidity, and electricity data and outdoor climate such as direct and diffuse solar radiation, temperature and humidity, wind direction and wind speed was installed in the case study “3 de Fevereiro Residential” building. The measured indoor and outdoor climatic factors were necessary for gauging the predictions of the simulation tool. From a literature review and the inspection done in the case study building, it was found that the existing appliances in residential buildings are old and energy inefficient. An analysis showed that using new and efficient technologies for air conditioning, appliances and for lighting could result in a reduction of electrical energy use by 24%. It was concluded that the improvements mentioned above can be enhanced with the use of renewable energy such as solar panels. To test this, a photovoltaic system generating electricity from the sunlight was designed and installed in the “3 de Fevereiro building”. The system supplied the building with electricity for cooling and lighting. This research system proved to work well and included the possibility to collect data via internet. The use of renewable energy is vital in improvement of electrical energy used in urban and rural zones. The constraint for its use is related to the price which is unaffordable for the majority of the Mozambican population living in rural zones. Thus, loans and incentives from the government for households who need to use efficient appliances and solar panels is highly recommended.