GHG reduction and energy efficiency analyses in a zero-energy solar house archetype

The objective of this study is to validate a zero-energy solar house (ZESH) as a sustainable development tool, based in accounting greenhouse gases (GHG) emissions mitigation. The method considers a multicriterial assessment for electricity conservation, power generation and GHG reduction. The potential and limitations of photovoltaic systems (PVSs) and the electricity consumption of the residential sector are studied. The guidelines and strategies of a ZESH are defined, focusing on the use of the sun in architecture, solar heating and PVSs through a qualitative analysis. These studies are carried out through a zero-energy house model (considering the annual consumption of a residence connected to the grid) that incorporates the guidelines and strategies of a solar house. The bioclimatic strategies and solar systems are analysed considering its application in São Paulo. The evaluation of passive strategies for thermal conditioning demonstrates a potential to increase by 70% the hours of comfort in the year. Using more efficient technologies for artificial lighting shows an energy conservation potential of around 12.5%, within the defined parameters and considering the average residential consumption. The use of a solar system to heat water has the potential to save up to 16.3% of energy compared to a business-as-usual scenario (traditional house). The electricity generation by PVSs combined with the adoption of energy efficiency measures demonstrates a potential to achieve, at least, zero net annual energy balance relative to the business-as-usual residential consumption of the grid. Thus, a potential to avoid up to 1.66 t CO2 per year for each housing unit is estimated.