The Energy Context
Buildings consume about 40% of our total energy needs. Large amounts of CO2 are produced during both construction and maintenance. This means that if we succeed in making the building industry more energy-efficient, we can also make a significant impact in the effort to prevent global warming.
Against this backdrop, media façades appear at first glance as relics from a less aware era, where no thought was put into energy consumption of buildings. We, on the other hand, are hard at work to reinvent the media façade as an agent of sustainability. To achieve this, we have turned to organic photovoltaics: attractive for both their energy-efficient solutions and their design potential.
A Self-powering Media Façade
We imagined a zero-energy media façade: a self-sufficient mechanism, capable of generating the electricity it consumes. To effect this, we place two double-sided LED lights in the centre of a rhombus made of polycarbonate. Over the entire plane of this semi-transparent support, a wafer-thin layer of organic substrate is built in. The substrate converts sunlight into electricity. While this energy does not directly illuminate the adjacent LEDs, and only feeds directly into the power grid, the power produced is always equal or greater than the energy required by the façade. During the day the façade produces more, at night less — in accordance with its needs. Thus, it is self-sufficient in daily use.
Solar cells that convert the sun's radiant energy into electrical energy are the basis for this. Organic photovoltaics (OPV) are able to achieve this function. In comparison with conventional crystalline silicon cells, they are not based on rare earths, rather organic hydrocarbon compounds. Although less powerful, they conserve production resources and are therefore more environmentally friendly. For a façade that in itself does not require very much energy, this is exactly the right solution.
OPV are suitable for the creative design of media facades precisely because the very thin layer of photoactive hydrocarbons and deducing electrodes can be applied to almost any material and shape. As long as their exteriors are shielded from oxygen, water and mechanical stress, these solar cells can be given almost any conceivable shape.
Shimmering Solar Elements
When the opportunity arose to develop a media façade for the ring-shaped exhibition pavilion by Michele de Lucchi Architects, on the Novartis Campus in Basel, we took advantage of the creative freedom the OPV cells presented. Thousands of shimmering diamond shaped OPV cells will span the curved façade (here pictures of a prototype). They will not only reflect the sunlight, but also convert it into electricity needed by the LEDs embedded in them. These shine outwards, and also downwards onto the layer of façade below. The colored light patterns thus also move behind and between the semi-transparent OPV cells. In this way, the solar cell required for energy generation itself becomes the protagonist of our newest media architecture.