Perovskites have spent years as the exciting material that might make solar panels dramatically more efficient. Their lab results are still compelling. The harder question is now outside, where light, heat, oxygen, water, and time all take turns being rude.
Efficiency Is Only the First Verb
A cell can perform brilliantly for a short test and still fail as infrastructure. Field tests ask a less glamorous question: what happens every day?
Why Tandems Matter
Silicon cells are mature and reliable. Adding a perovskite layer can capture parts of the spectrum silicon misses. That is the promise. The engineering problem is making the stack survive.
The Deployment Question
The winning technology may not be the absolute record holder. It may be the design that can be manufactured consistently, repaired sensibly, and insured without heroic assumptions.
