Current distribution networks for electricity do not work well enough to transport large quantities of electricity for long distances.
In my opinion, this is the main issue that needs to be solved. Currently, we have centralized power plants with constant output, which distribute energy over medium ranges.
Decentralized energy production with fluctuating output doesn't play well with the existing network. However, that's not an unsurmountable problem - it's just not profitable as long as fission and fossil fuels are acceptable alternatives.
In my opinion, this is the main issue that needs to be solved. Currently, we have centralized power plants with constant output, which distribute energy over medium ranges.
Decentralized energy production with fluctuating output doesn't play well with the existing network. However, that's not an unsurmountable problem - it's just not profitable as long as fission and fossil fuels are acceptable alternatives.