The -ism word ending adds a slightly negative connotation to a variety of concepts, turning them into “doctrines” supported by adepts that are somehow deprived of critical thinking. Like Patrik Schumacher launched Parametricism in the attempt to convert the practice of parametric design into an influential theory, the belief that photovoltaic panels should be part of any projects could be called Photovoltaicism, but far be it from me to theorise it.
There is an increasing number of solar energy enthusiasts, which would be positive if they didn’t want to apply solar panels onto any surfaces regardless of the orientation, geometry and shading conditions. Including solar power installations in architecture projects has become a sort of marketing strategy. Companies and property developers like to show off solar panels as a symbol of their supposed commitment to sustainability. Typical examples are the design for the Apple headquarters in Cupertino, with its photovoltaic roof, and the photovoltaic glass façade of the Heron Tower in the City of London.
While having solar panels on display can be beneficial to a company’s image, it might not be so relevant in terms of energy performance if the installation is designed without properly taking into account the parameters that affect the efficiency of photovoltaics. Factors such as non-optimal orientation and tilt, high temperature, curved geometries and shading can decrease considerably the efficiency of photovoltaic panels. For instance, the efficiency of a vertical photovoltaic façade is reduced by approximately a 30% compared to that of an installation with optimal tilt. When enthusiasts come up with a desire for solar panels, it can be hard to dismiss their ideas because the location they had in mind is facing the North or because there are some nearby trees and buildings casting shadows. Nevertheless, I think solar installations should be designed to perform optimally both from a visual and from an energy perspective, especially when integrated into architectural skins.
So-called sustainable design is supposed to prevent the waste of resources as much as possible. I have learned that installing solar panels on any urban surface by overlooking the parameters that can maximise their efficiency is wasteful, as it does not exploit the full potential of photovoltaic materials and can lead to using more active material than is really needed. Therefore, covering a building with photovoltaic panels is not necessarily sustainable, rather the solar panels may have more a “decorative” or symbolic function than being highly effective energy generators. If not accurately designed, solar facades, solar roofs, solar lighting and any other solar installation can be a waste of resources. Architects and designers have a responsibility for preventing this type of waste. A solar installation is not just a black or dark bluish patch that can be pasted anywhere in a CAD model or in a Photoshop image. A landscape, building, artwork or any object is not necessarily better or more “sustainable” because it has solar panels. It all depends on how intelligently the solar installation is designed, also in relation to the context it is inserted in. Skilful design is the key to sustainability.