A Case Study on a Stochastic-Based Optimisation Approach towards the Integration of Photovoltaic Panels in Multi-Residential Social Housing

Rui Oliveira,Romeu Vicente,Ricardo M.S.F Almeida,António Figueiredo

doi:10.3390/en14227615

Abstract

The socioeconomic reality and the energy retrofit potential of the social housing neighbourhoods in Portugal are stimulating challenges to be addressed by research to pursue suitable energy efficient strategies to be integrated into these buildings. Therefore, this study explored a stochastic-based optimisation approach towards the integration of photovoltaic (PV) panels, considering different scenarios that combine the occupancy rate, the internal gains, the envelope refurbishment and the heating system efficiency. The optimisation approach has as its objective the minimisation of the life cycle cost of the photovoltaic system while using a limited space area on the rooftop for its installation. This study allowed concluding that the use of passive measures such as improving the thermal performance of the building envelope is essential to attain a lower optimal-sizing of a photovoltaic installation. The results reveal a decreasing trend in the PV optimal sizing, attaining a reduction up to 30% of the total number of PV panels installed on the sloped rooftop in several scenarios with 50% of occupancy rate. However, the impact can be greater when passive measures are coupled to more efficient heating systems, with higher COP, which result in a decrease up to 64% of the number of PV panels. Thus, the approach proposed is of paramount importance to aid in the decision-making process of design and sizing of photovoltaic installation, highlighting the practical application potential for social housing and a contribution for mitigation of the energy poverty of low-income families that live in these buildings.

Highlights

The European building stock from the 1970s to the 1990s represent the largest share of the existing buildings and are considered the least energy-efficient, presenting enormous potential for intervention
The total energy demand is used as input for the calculation of the Net Present Value (NPV) value associated with the integration of photovoltaic panels
This study has highlighted the need to define a robust approach to assess the impact of improvement measures, both active and passive, on the energy efficiency in social housing buildings, tackling the optimisation approach for photovoltaic energy system design, as a contribution for mitigation of the energy poverty of low-income families that live in these neighbourhoods

Summary

Introduction

The European building stock from the 1970s to the 1990s represent the largest share of the existing buildings and are considered the least energy-efficient, presenting enormous potential for intervention. The massive construction of new buildings and infrastructures has been progressively slowed down, giving priority to the rehabilitation of existing buildings and built heritage. According to this tendency, new challenges and funding programs have emerged across. The enormous potential to decrease energy consumption and the advances in renewable energy technologies were two of the main drivers for the implementation of nearly zero energy buildings (nZEB) over the last decade and have led member states to outline new measures and guidelines at the national scale to encourage the refurbishment of existing building stock [7].

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Results

Conclusion