This new solar technology can be printed or woven into fabric


This is perovskite – the mineral behind an exciting new generation of solar cell technology

 Image: Rob Lavinsky,iRocks

Our planet is facing an unprecedented global emergency due to the climate crisis. To counter thus narrative we need new and disruptive energy technologies. Breakthroughs here can make our planet a better place to live, minimize the deleterious effects of climate change and ensure a high standard of living. Harvesting energy through green and clean means is the way forward to preserve our civilization. As Jimmy Carter once said: no-one can ever embargo the sun or interrupt its delivery to us”; the sun is the best gift to humanity and harvesting sunlight at a cut-rate price will solve our energy demand issues to a large extent.

Renewable technology will drive the energy transition and will also induce geopolitical shifts, creating new alliances and business models. Countries that are currently fossil fuel suppliers will need to reinvent themselves or embrace new technological approaches in order to remain competitive. Our planet’s current energy demand is approximately 16 Terawatts (TW); by 2050 we will need energy for 10 billion people, and this will be around 30TW.

To bridge this gap, we need new approaches and changes to the current paradigm. The electric light did not come from the continuous improvement of candles, but through disruptive innovation. The societal pressure to embrace sustainable energy has made photovoltaics (PV) – or solar panels – one of the main contenders. Currently, the PV industry is dominated by silicon-based technology, which has reached the masses and has achieved grid parity (that is, cost parity with traditional sources of energy) in some parts of the world. The costs for solar energy have already fallen 77% from 2010 to 2018 due to an annual growth rate of 7.9% in renewables.

In recent years, the PV sector has witnessed a surge of installments and drastic price reduction; however, the manufacturing of silicon solar cells remains an energy-intensive process – that is, the energy consumed to produce the technology – the energy payback time – remains high, and the production rate is not equipped to adapt quickly to the challenges of satisfying future demand. But today a new breed of solar technology could prove to be the answer.

Classical silicon-based solar cells are today a mature, or first-generation, technology. They were superseded by thin film-based PV cells; these are made by depositing thin layers of a light-harvesting material on a substrate, which can be glass, metal or plastic. This technology uses exotic materials in extremely thin layers, however, which makes it difficult to be cost-competitive with traditional silicon-based PV cells.

But today a new source of sustainable solar energy is under development that could have a low energy payback time, and a cost that could see it deployed widely. This technology – characterized as emerging PV – is based on nanostructured or carbon-based materials such as dye, perovskite (a family of man-made crystals), or organic-based solar cells.

Recently, we have witnessed an unprecedented rise in the investigation of perovskite materials for solar cell fabrication due to their excellent semiconducting behavior, ease of manufacture and high level of efficiency. In less than a decade, it has outperformed all the existing thin film PV technology and can now compete head-to-head with mature silicon technology in terms of solar-to-electric efficiency.

Perovskite-based PV cells use an ultra-thin layer of material

Perovskite-based PV cells use an ultra-thin layer of material, and this allows perovskite to be cost competitive – along with its easy processability due to its high tolerance for manufacturing defects. In the future, economies of scale and technological advancements will cut fabrication costs even further.

Perovskite is a semiconductor, light-absorbing pigment. Its versatility means it can be formulated as an ink, which can then be printed at any possible object – and this means employing routine printing processes such as inkjet technology, painting surfaces with brushes or newspaper printing could be adopted for mass-scale production.

This new source of sustainable energy – with its low energy payback time, portability and flexibility – is fully equipped to reach the masses. It can also be formed into threads and woven into fabrics, bags or building materials. Perovskite solar cells have made stunning progress within a short timeframe at the laboratory scale; now we need to join forces and create synergies through chemistry in order to improve the material’s stability.

Greenhouse gas emissions are a threat to humanity everywhere. but don’t panic – instead, let’s build the future together though disruptive innovation.