It varies, depending on many factors. a study from 2001 cites 81%. bear in mind the tech has come a long way since then, and China is far ahead in production of commercial examples, so getting efficiency quotes in English is tricky. Note also the consequence of lower efficiency in a money-fuel tree is just more panels needed at the front end, to di the same amount of work.
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/30535aw.pdf&ved=2ahUKEwjzxPuTir_3AhW0pnIEHet4AQIQFnoECBcQAQ&usg=AOvVaw1wgKcUaGbidUB7pu-1b4wR