Multi-Period Optimisation of District-Scale Building Integrated Photovoltaic Deployment

The deployment of solar energy technologies such as building integrated photovoltaics (BIPVs) is one of many ways to mitigate present greenhouse gas emissions and abate GHG emissions in future urban development. The widespread deployment of BIPVs is therefore ideal, but deployment must be met with an understanding of the life cycle carbon associated with the technologies manufacturing and their availability as a finite resource. In this paper we describe deployment schedules over the next several decades for BIPVs in a redeveloping urban quarter in Zürich, Switzerland, known as Altstetten. Altstetten has near term goals for carbon neutral buildings that must be met through energy retrofits, higher building standards, and renewable energy. In solving how best to deploy BIPV systems to reduce the life cycle emissions of the buildings in Altstetten, we develop a multi period deployment scheme from a Mixed Integer Linear Programming optimization model that determines the optimal PV deployment within a larger urban multi-energy system. This approach intermingles spatially resolved optimisations with temporally resolved projections of how to deploy the BIPV systems. We analyse results of several optimal solutions sets to investigate the role urban morphology and BIPV embodied emissions play in BIPV utility. We find that different planning strategies (e.g. reduce cost before carbon emissions) play a role in the quantity and rate at which BIPV could be expected to be deployed and that a strategy of minimizing carbon before cost results in less required BIPV deployment than if cost is of the prime concern.