A tandem cell from Berlin converts 32.5 percent of the light into electricity. Panels with such cells would produce almost half as much electricity with the same area.

Researchers from Berlin have set a world record. Their tandem solar cell converted 32.5 percent of the sun’s energy into electricity. That is almost a third more than conventional solar cells that you can currently buy. Calculated from the new cell. If you look at the commercially available panels (efficiency around 21.9 percent), the increase is even around 50 percent. The trick was successful with a so-called tandem cell. Two cells are superimposed here. The bottom is a silicon cell, with a perovskite cell on top.

“This is a really big leap forward that we didn’t anticipate a few months ago,” said Steve Albrecht of Helmholtz-Zentrum Berlin (HZB). “All the teams involved at HZB, especially the teams from the PV Competence Center (PVcomB) and the HySPRINT Innovation Lab, worked together excellently and with great dedication.” With 32.5 percent, the Berliners were able to surpass the previous record of 31.3 percent set by the École Polytechnique Fédérale de Lausanne (EPFL). Both institutes are in a race. The EPFL was the first to surpass the 30 percent mark, previously the Berliners held the record.

Solar energy: More electricity from the same area

Both layers of the tandem cell use different parts of the light. The silicon cell emits the red rays and the top cell blue rays. The problem with these cells is the permeability of the layers in the cell structure. The record is just another milestone. In recent times, records have been pushed to and above the 30 percent mark. These are still laboratory tests, but they show where development is headed. If these tandem cells go into series, the performance of a panel can be increased enormously. On the surface where 400 watts of power can be achieved today, almost 600 would then be possible.

The HZB is working on initiating industrial production of the cells together with the company Meyer Burger from Switzerland. However, the tandem cells are likely to be expensive to produce. But since in most cases the area for the solar panels is limited, a panel with that much higher efficiency would probably be successful. Especially since an end to the records is not in sight.

What: HZB