Combined cycle powerplants are > 60% efficient (LHV). The LHV of hydrogen is 33.3 kWh (of heat) per kilogram.
Yes, it would be inefficient overall. And it's still cheaper than nuclear. Throw in a large fraction of energy not going through hydrogen (direct to grid, or through batteries) and the cost would be even lower.
Yes, it would be inefficient overall. And it's still cheaper than nuclear. Throw in a large fraction of energy not going through hydrogen (direct to grid, or through batteries) and the cost would be even lower.