You need H2 only after solar + EVs provides more than 24 hours of needed energy in an area. Although H2 does save on transmission costs for medium to long distance. One of the remarkable aspects of BYD Dolphin, now under $9000 for 32kwh battery is that the battery value alone is $260/kwh capacity, and if you never drove it, but sold electricity 2.6c/kwh higher at night than you pay at day, then you pay for the car in its entirety. Just batteries can be sold under $100/kwh in China, and you could make 200% ROI from 3c/kwh price differential. EVs and batteries can be paid by private sector instead of utility investment markup model.

H2 technologies are advancing, including storage and pipes. Electrical transmission is more than 10x more expensive than transmitting gas/H2, and saves money on that end relative to efficiency loss. Surplus solar with input cost at 2c/kwh or less achieves under $2/kg H2 target which is equivalent driving distance to $1/gallon gasoline, and 10c/kwh electric only value delivered energy, and 6c/kwh combined heat and electricity value.