Solar textile for building exteriors gives power dressing new meaning

A durable solar textile that turns buildings into massive electricity generators is being developed by a Dutch fashion designer with a market-ready product expected within three years.

Pauline van Dongen, whose smart solar clothing has graced catwalks worldwide, teamed up with engineering consultancy Tentech to develop Suntex, which is backed by a EUR100,000 grant from the Netherlands government that is matched in kind by the project partners.

The flexible, lightweight and water-resistant textile is created by weaving together organic photovoltaic (OPV) solar cells, made from polymers, with recycled polymer yarns. It is intended for use as a cladding material for new or retrofitted buildings or as a form of solar shading for glazing.

A focus on sustainability is expected to result in a cloth with low embodied carbon that can be easily dismantled and recycled at end of life.

‘The facade is a huge untapped potential for solar in most northern European countries,’ van Dongen told RIBAJ in an exclusive interview. ‘Although all kinds of materials can clad facades for solar, including building integrated photovoltaics, we are hoping to add a new material to the library to help architects create a better fit both aesthetically and functionally.’

Research is currently on a ‘semi-industrial scale’. It has produced a series of sample solar textiles that have been mechanical and electrical tested with fully-automated looms able to weave the OPV and polymer strands in development.

OPV is less efficient than regular solar panels, but spread across a large surface area it could generate a significant amount of electricity. A theoretical case study of the Westraven building (which has the largest textile facade in the Netherlands) covered with 5,000m² of active OPV was calculated to produce 320.4MWh each year. That equates to 4% of the building’s total energy consumption, enough to fulfil all its lighting requirements. The additional benefits of sun shading and thermal isolation have yet to be quantified.

‘Suntex also provides the qualitative benefit of a completely new aesthetic appearance, or aesthetic upgrade in the case of existing buildings, contributing to the social acceptance of solar technology,’ says van Dongen.

Tensioning and loading on the material is a critical factor, the designer adds, as it will be stretched across an aluminium or steel frame to create an external screen across the facade. Through a modular approach the cloth could be scaled up to cover anything from a 10-storey to a 40-storey building, adjusting power supply and power output to suit.

The textile is expected to have low embodied carbon compared to solar panels, due to the use of OPV, which is widely recognised as a highly sustainable solar material, and organic polymers made from recycled material. The lightweight structure and focus on recycling should cut the amount of carbon used in production.

‘Sustainability is a big issue in the fashion industry, including the materials you choose and how to recycle them,’ says van Dongen. ‘One thing we're running into in the construction market is that textiles are often heavily coated and their composite character makes recycling difficult, especially when you integrate solar technologies…it raises questions about how we make these materials more sustainable,’ she concludes.