A solar solution for the future

Organic photovoltaics: Shining a new light on solar power

05 December, 2016
Sunlight is an abundant energy source offering a clean alternative to fossil fuels. Photovoltaics (PV) capture the sun’s energy, converting sunlight into electricity. However, applications for conventional PV technologies are limited by their weight and fragility. Organic photovoltaics (OPV) now promise the light weight and flexibility needed for wider use.

PV is one of the most exciting technologies in the race to find sustainable energy sources. By harnessing the power of the sun, we can generate electricity with a low carbon footprint for on- and off-grid applications. This renewable source of energy can already be seen in action around the world, with solar panels on rooftops powering buildings and feeding the grid.

Although PV is a growing and valuable technology, its applications are limited. That’s down to several key factors:
  • Weight: Solar panels are heavy – a standard 1 x 1.7 metre panel weighs 25kg. Add the frame, and it’s up to 50-60kg. You need a really strong roof to support that weight.
  • Fragility: Conventional, crystalline solar cells are incredibly brittle. So, if you want to bring a solar panel to a rainforest in Brazil or a remote place in Africa along bumpy roads, there’s a high risk of breakages.
  • Environmental impact: Conventional crystalline solar cells require energy intensive high temperature processing, whereas OPVs are printed at low temperatures on thin polymer substrates.

A new dawn for solar power

This is where OPV – one of the newest technologies – come into play. OPV are specially designed, printed organic molecules that harvest the light of the sun to generate electricity. The material is so lightweight and flexible that you can stick it directly onto a building or integrate it with a steel panel during construction. It can even be retrofitted to existing buildings in the form of decorative adhesive films for windows. The cost of installation is much lower, so the application opportunities are also broader.

A flexible OPV can be rolled up in a tube. It’s robust, so you can transport it to the most challenging places. Plus, you can apply printed OPV cells to surfaces that aren’t flat – so they could be used to create new nomadic consumer items, like tents or backpacks that light up at night. Really, our imagination is the only limit.

OPV has huge potential but brings its own challenges too, mainly around lifetime, efficiency and industrial scale up production. There is a great need for collaboration from a broad range of industries and researchers to bring this technology to a wider use.

The Sunflower project

To further develop OPV and demonstrate applications, 17 academic and industry partners across the supply chain joined up to form the FP7 Sunflower project, which was funded by the European Union. Amcor was a member of this consortium.

The goal of Sunflower was to develop more efficient, affordable and long-lasting printed OPV materials, with minimal environmental impact. The group focused on making the printed molecules more effective at harvesting light, and explored sustainable alternatives to the rare organic components.

OPV cells degrade over time with exposure to oxygen, moisture and light, so the team also looked at how to encapsulate the films in order to preserve the organic molecules. Ultimately, the aim was to make the technology reproducible on a larger, industrial scale, making OPV an affordable option for new consumer applications.

Amcor’s contribution

In the four years leading up to March 2016, when the project drew to a close, Sunflower made huge inroads into the development of OPV, including the creation of new materials offering lower production costs than competing solutions. In a laboratory setting, the efficiency of OPV cells has now reached 10 per cent. These results will help the European Union, which invested €10m in the project, to fulfil its goal of raising renewable energy usage from 14 per cent in 2012 to 27-30 per cent by 2030.

Sunflower was a great match for Amcor because of our strong focus on sustainable technologies. Our solar solutions include transparent, durable, high-barrier films used in photovoltaic technologies. These allow solar cells to operate in more extreme conditions and climates by protecting them from moisture and oxygen. They are thin and light, and therefore suitable for a variety of applications – from boat decks to building facades. They are also a great option for OPV encapsulation.

Thanks to learnings from the Sunflower project, we’ve made a leap forward in the Ultra Barrier Technology used in these films, achieving moisture barrier levels not previously possible in industrial-scale production. We’re now in the process of scaling up so we can bring these improvements to the market.

Future Uses

OPV technology has had great potential for a number of years now, especially in applications where aesthetics are important. By resolving key challenges, the Sunflower project has paved the way for far wider use of solar power – for example in consumer electronic devices.

The ‘Solarte’ series from consortium member Belectric is really exciting. It offers ways of integrating energetically active components into architecture and product design. It’s very flexible in terms of colour, shape and materials, so it can be used to harness energy in all sorts of products, from sports and fashion accessories to urban furnishings and lighting solutions.

Sensors for smart buildings is another interesting area. Take smoke alarms and infrared detectors – they need power and currently that comes down to wiring them in or using batteries, which are costly. OPV can harvest ambient light, even in low light levels, to opening up new applications.

At Amcor, we’re now working on new ways to create PV substrates that are more durable, so that OPV can be used in an even wider range of applications.

Learn more about Amcor’s commitment to solar-powered sustainability and the Sunflower project, or contact us now.