depends on if that rate continues or levels off. I imagine it does level off, but it wouldn’t be immediately after the 10% loss.

The perovskite solar cells (PSCs) are capable of retaining over 90 per cent of their initial performance after 600 hours of continuous operation, the team noted, making them suitable for commercial use.

That’s what the article says - it leaves a bit to interpretation, for sure. But “viable for commercial” must imply that it’s not useless after a couple months.