Basically big if true, but this thing's 40% and photovoltaics' 20% aren't comparable efficiency numbers.
* They say wire to wire, IDK exactly what that means, but if it includes the losses from green hydrogen production then it seems like pretty wild efficiency. This doesn't line up with the numbers though, as H2 with 1250Wh/L * 0.4 = 500 Wh/L claimed density.