Beyond Silicon, Caelux, First Solar, Hanwha Q Cells, Oxford PV, Swift Solar, Tandem PV
3 to 5 years
An innovative solar technology set even another world record for efficiency in November 2023. It had only been in existence for roughly five months, and it won't be long before the previous record becomes outdated as well. Perovskite tandem solar cells are a unique type of next-generation solar technology that is responsible for the startling acceleration of efficiency advances. These cells combine materials with similar crystal structures on top of conventional silicon.
Perovskite solar technology has continued to surpass its own efficiency records, which gauge the percentage of sunlight that is turned into power, during the ten years that scientists have been experimenting with it. Perovskites absorb light at different wavelengths than silicon cells, which currently make up 95% of the solar market. In tandem solar cells, the combination of silicon and perovskites allows for greater use of the solar spectrum, resulting in higher power output per cell.
Perovskite-only cells have achieved experimental efficiencies of about 26%, while silicon-based cells have a maximum technical efficiency of less than 30%. However, in the laboratory, perovskite tandem cells have already surpassed 33% efficiency. The alluring promise of this technology is that, if used extensively, perovskite tandem cells might generate more electricity than conventional solar cells at a cheaper cost. However, in practical use, perovskites have shown to be unreliable. Solar cells made of silicon have a long lifespan. Not many perovskite tandem panels have even undergone outside testing.
Perovskites are susceptible to absorbing moisture and deteriorating in heat due to their electrochemical composition; nevertheless, scientists have been trying to improve the barriers surrounding panels and switch to more stable perovskite compounds.
Other companies could reveal products later this decade. In May, UK-based Oxford PV announced that it had achieved an efficiency of 28.6% for a commercial-size perovskite tandem cell, which is significantly larger than those used to test the materials in the lab. The company plans to deliver its first panels and ramp up manufacturing in 2024.
The 60-cell residential-size solar panel has achieved a conversion efficiency – the proportion of solar energy shining on a panel turned into electricity – of 26.9%, surpassing the current best silicon panels of roughly 25% with a similar defined panel area.
The efficiency was independently measured and certified by Germany’s Fraunhofer CalLab.
Oxford PV's secret weapon is its proprietary high-efficiency tandem solar cells, which can theoretically reach over 43% efficiency, leaving traditional silicon solar cells, which have a theoretical limit of less than 30%, in the dust. Based in Yarnton, England, the company develops solar technology and produces its panels at its factory in Brandenburg a der Havel, Germany. Within the next few years, it plans to scale up its manufacturing of tandem solar cells to gigawatt volumes.
