Solar Heating and Cooling in Buildings – How Sustainable?

Abstract

Conventional heating and cooling systems are responsible for large amounts of carbon dioxide release to the environment, as well as for the use of harmful refrigerants regarding the greenhouse effect and the ozone depletion potential. Solar radiation is a clean form of energy, which is required for almost all natural processes on earth. In South Africa, the majority of produced electricity is generated from fossil fuels and the potential of renewable energy sources is vast, solar radiation in particular is in abundance. The upper limit for Global Horizontal Irradiance (GHI) in South Africa can be as high as 2 300 kWh/m2/a, whereas the Direct Normal Irradiance (DNI) value attains a maximum of 2 900 kWh/m2/a, which is significantly higher than it is in other regions worldwide. The global air conditioning systems market has been estimated to reach 78.8 million units by 2015 due to increasing living standards, comfort expectations and global warming. South Africa is not the best performer regarding renewable energy use among African countries and there is a long way to go to achieve a sustainable environment. This paper seeks to investigate the feasibility and the sustainability of solar driven air conditioning system in South Africa based on meteological weather data. Currently, renewable energy is a topic of interest in South Africa after the 2008 energy emergency when power outages were rolled out due to inadequate maximum load planning. Solar air conditioning technology remains an untapped technology in South Africa.