Why would you want to use electric power anyway? Its the type of energy thats the hardest to aquire (we use chemical energy in lots of powerplants to create electrical energy with bad efficency). For a enviromental friendly rocket you could still rely on chemical propelants, e.g. hydrogen created by electrolysis of renewable energy. Thats way easier due to the high energy density of chemical propulsion...
Elon Musk (SpaceX) said every form of transportation will eventually go electric…with the exception of rockets.
You just mentioned one of it. What if going electric makes for a lighter booster? Wouldn't that save some cost in terms of being more efficient and cheaper? There are loads of reason to go electric, if (that's a big if) it's practical. You know it can also be easily reused if based on batteries, etc.