Optimal carbon-neutral retrofit of residential communities in Barcelona, Spain

This paper investigates the optimal retrofit solutions for residential communities to be carbon neutral in Barcelona, Spain. In particular, three different sizes for the residential communities are considered depending on the number of housing units: small, medium, and large. First, the best cost-effective energy efficiency measures (EEMs) have been determined and applied to all the buildings of the communities, in order to reduce their overall energy demand. The retrofit optimization results demonstrate that combinations of passive and active strategies would achieve source energy use saving and electrical peak demand savings up to 57% and 29%, respectively. Then, a variety of renewable energy generation systems has been explored to determine the optimal grid-connected technologies for meeting the electricity demands while achieving annual carbon neutral conditions for the residential buildings. The analysis shows that wind turbines can reduce the cost of electricity generation up to 21.5% compared to the current utility prices (LCOE value as 0.247 (sic)/kWh) and electricity sell back policies. The results indicate that for PV systems to compete with wind turbines, their capital costs need to be lower by at least 40% compared to the current level costs. (C) 2019 Elsevier B.V. All rights reserved.