Quite often there is a tendency to avoid the use of photovoltaics because it is believed that it costs significantly more than traditional building solutions.
Self-consumption or optimization of the energy production?
Since most European countries abrogated the program of incentives “Feed-in-Tariff”, in order to maximize the economic benefits of a photovoltaic system, it is necessary an increase of the self-consumption rate of the energy produced. A photovoltaic system should be ideally designed considering the energy demand hourly profile of the building. A photovoltaic installation on an east or west oriented roof or facade, compared to a traditional south-oriented one, allow to better cover the morning and afternoon electric load peaks.
Daily load profile and energy production of a multi-unit building.
Is a BIPV envelope really more expensive than a conventional one?
A BIPV system integrated into a facade or into a roof is often classified as a cost ineffective building solution. This happens when the BIPV envelope is directly compared with a similar non-photovoltaic solution (cladding in fiber cement, stone, glass, tiles, etc.) without considering the economic benefits of the energy production. In reality the extra cost of a BIPV solution is the difference between the cost of the photovoltaic cladding plus the accessories to make it active (BOS) and the cost of a similar solution without the photovoltaic components.
Extra cost definition.
A practical example for a BIPV facade and roof in Ticino
In the following table are listed the information needed to calculate the return on investment (ROI) of a BIPV facade and roof installation in southern Switzerland. Compared to a non-active solution (fiber cement cladding), the extra cost of the BIPV cladding will be recovered in 12 years.
