Design of carbon neutral communities in Spain

Abstract

This study investigates the optimal retrofitsolutions for residential communities to be carbon neutral in Barcelona, Spain. The residential building stock in these communities includesthree prototypical dwelling types: detached, attached, and apartment.In this study, three different sizes for the residential communities are considered depending on the number of housing units: small, medium, and large. First,the bestcost-effectiveenergy efficiency measures (EEMs) have been determinedand applied to allthe buildings of thecommunities, in order to reduce their overallenergy demand.The retrofit optimization results demonstratethat combinationsof passive and active strategies would achieve source energy use saving and electrical peak demandsavings up to 57% and 29%, respectively.Then, a variety of renewable energy generation systems has been explored to determinetheoptimal grid-connected technologiesfor meeting the electricity demandswhile achieving annual carbon neutral conditions for the residential buildings. The analysis results indicatethatcurrently,wind turbines would be the most cost-effectiverenewable generation systems for the residential communities in Barcelona to be carbon-neutral. Specifically, the analysis shows that wind turbines can reduce the cost of electricity generationup to 21.5%compared tothe currentutilityprices (LCOE value as 0.247 €/kWh) and electricity sell back policies. The results indicate that for PV systems tocompetewith wind turbines, their capital costs need to be lower by at least 40% compared to the current level costs