Now we have some knowledge about the levelized costs of electricity generation.
Because the intermittency of renewable electricity, energy storage technologies are getting much attention nowadays.
So I googled this figure ("Ranges of levelized cost of output electricity for electricity storage systems").
FC/ aboveground: hydrogen fuel cell with aboveground storage
FC/ geologic: hydrogen fuel cell with geologic storage
CAES: compressed air energy storage
Last week, one person who has been working in an energy consulting company told me that the economics of compressed air electricity storage was not satisfactory to utility companies. His remarks conflict with this NREL analysis result.
Or, if both are right, none of the electricity storage technology is commercially viable.
Source: Steward, D., Saur, G., Penev, M., & Ramsden, T. (2009). Lifecycle Cost Analysis of Hydrogen Versus Other Technologies for Electrical Energy Storage (NREL/TP-560-46719). Golden, CO: National Renewable Energy Laboratory.