34.6 percent efficiency confirmed for perovskite tandem solar cell

According to manufacturer Longi, the remarkable efficiency of 34.6 percent has already been confirmed by the European Solar Test Installation. This EU-funded authority measures and tests solar modules. Long-term tests are also carried out there.

This should ensure that almost 35 percent of the energy of the incident light is converted directly into electricity. This means that the last world record - also set by a Longi module - from exactly one year ago has been beaten by 3.3 percent.

Compared to the solar cells currently in use, this is over 50 percent more efficient. A photovoltaic system of this type could therefore generate half as much electricity on the same surface area. If an older system, which is probably no longer at full capacity due to its age, were installed, the amount of electricity could even triple or quadruple.

This outstanding value is made possible by combining the promising perovskite solar cells with classic silicon-based cells. This takes advantage of the fact that perovskite modules are almost completely permeable to long-wave light in particular.

This longer-wave light, which is mostly in the infrared range that is no longer visible, is converted into electricity by typical silicon-based solar cells. If you like, the two technologies complement each other almost perfectly.

The efficiency of 22 to 25 percent now achieved by commercial solar cells and almost 20 percent for perovskite could therefore be used to construct an even better solar module at some point, or even in the near future.

The only remaining problem is durability. The mineral perovskite in solar modules currently loses its performance too quickly. The efficiency drops rapidly - faster than would be desirable for the system on the roof or in the field.

Nevertheless, progress is still being made in this area. Recently, a commercially manufactured PV module with a 10-year guarantee was was presented, which is based on perovskite. According to the manufacturer Utmo Light, the service life of the cells themselves is even 25 years. However, there is still room for improvement in terms of efficiency.

So there is still a lot to do. However, a few scent marks have now been set.