The world’s first large-scale production of perovskite solar cells has started in a surprising place. Perovskites have been hailed for a decade as having the potential to transform the way we produce electricity and initiate an age of clean energy production. However, after the failures of so many other technologies to live up to the hype, most observers have not wanted to get their hopes up too much. We may be about to find out whether this is the real thing.
Most current solar power uses silicon photovoltaic cells. The fall in the price of silicon cells has been astonishing, costing less than 1 percent of what they did around 40 years ago, while efficiency and reliability have increased dramatically. No other energy source in history has got so cheap, so fast. However, solar engineers have acknowledged for a long time there are performance limits silicon cannot cross, and it looks like we’re getting close, driving a search for something better.
Perovskites (with suitable storage) look like the best chance to end fossil fuels' reign. It’s only nine years since scientists proved that crystals based around a calcium titanate structure and doped with tiny quantities of metals can efficiently convert solar power to electricity. In that time, their efficiency has improved far more quickly than any rival solar technology. Better yet, perovskites require far less energy and expense to make than silicon cells (which require high-temperature manufacturing) and are also potentially much more versatile.
In 2013, Dr Olga Malinkiewicz showed it was possible to manufacture perovskite cells with inkjet printing techniques, bringing the cost of production down even further. Nevertheless, predictions of mass production by 2018 were not fulfilled. Early perovskites degraded quickly on exposure to air and water. Moreover, all solar cells lose efficiency at larger scales compared to laboratory experiments, but the curve for perovskites was particularly steep. Progress has been made on both fronts, but these and other obstacles have prevented commercial-scale production.
Now, however, Malinkiewicz has launched the world’s first industrial-scale perovskite cell production line, using the inkjet printing technique she invented.
Malinkiewicz's company Saule Technologies, named after the Baltic Sun goddess, has started manufacturing in Wroclaw, Poland. The location is remarkable because Poland is Europe’s most coal-dependent country. Until recently, the political climate there was as hostile to solar, but that has turned around recently. The nation’s installed solar has jumped fourteen-fold in just three years, although it still remains low per capita.
Among perovskite cells' advantages is that they can be exceptionally thin, allowing them to be printed on curved surfaces and flexible rolls. Already, Saule boast of the uses found for their cells produced on a prototype line, including electronic price tags that operate off indoor light and windows with semi-transparent perovskite layers built-in.
The announcement does not mean the end for silicon cells just yet, however. Not only do Saule’s cells need to show they can live up to their promises, many people expect the medium-term future of solar power to lie in silicon-perovskite tandem cells. Many perovskite recipes produce cells that collect high-energy photons such as blue and violet light and let lower energy photons through. A thin layer of perovskite printed onto a silicon cell is likely to be the most efficient way to collect solar power over the next decade and may be the cheapest as well.
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