Photovoltaic aluminum: the incredible technology that could make solar panels disappear from our roofs

This is the heart of the German “Alu-PV” initiative, which brings together several organizations including the Hamelin Solar Energy Research Institute (ISFH), MN Metall GmbH, Baltic Renewable Partners and Fraunhofer CSP. The consortium has developed an original method for directly integrating photovoltaic modules into aluminum facade elements, without compromising on aesthetics or safety.

A lamination process

To design the photovoltaic facades, the researchers proceeded using a method called “lamination”. This involves assembling and sealing the different layers of a solar panel using heat and pressure. The technique was also used to directly integrate the module into the metal.

Concretely, the process is based on a standard membrane plate laminator, operating at 155°C and 1,000 mbar, with layers of silicone to compensate for differences in height of the 3D profiles. This allows the module to be glued directly to facade elements with complex shapes, without a custom machine.

Before arriving at the prototypes, the researchers had to overcome various technical difficulties. Because directly assembling solar cells on aluminum could cause deformation or even cracks.

Additionally, aluminum conducts electricity, making direct contact with cells potentially dangerous. The team had to find technical ways to solve these two big problems, and they succeeded.

Performances on point

Tests carried out on the prototypes delivered encouraging results. The photovoltaic cells showed performances comparable to those of conventional solar modules. After manufacturing, the modules were also subjected to electroluminescence imaging, a technique which reveals potentially present cracks or defects invisible to the naked eye. But no cellular damage was detected on the prototypes.

With the performance and integrity of the systems having been validated, the team also touts the design flexibility of its technology. Several geometric variations were manufactured: wavy, zigzag, rectangular surfaces, as well as customizable color options. The modules can also reach two meters in length.

So far, the consortium has manufactured three demonstration modules on anodized aluminum supports of different shapes. We therefore remain at the prototype stage: no marketing date or price has been communicated.

So many possibilities to meet the expectations of architects who are often reluctant to adopt solar solutions which constrain their creativity. “The developed prototypes only differ from a classic facade element by two connectors. For us, this is a key factor to guarantee acceptance by installers,” researcher Kevin Meyer told PV Magazine.

Obviously, questions of durability, resistance to thermal cycles in real conditions, or even manufacturing costs on an industrial scale will still need to be studied. But the technical demonstrations already seem solid, enough to potentially lead to commercialization.