Can't be everything. Electrical power is like 20-35% or so of total power used in most countries. I just checked some statistics of the Umweltbundesamt, the German ~environment protection office. The electrical fraction is suprisingly low! Though it's supposed to increase because most renewable energy production is electric.

My guess is nuclear energy, more efficient cars, better insulated houses, and less heavy industry.

If you have a price competitive modular rapidly approved and scaled meltdown proof plant design that can be built in a couple years.

Unfortunately, that does not exist in nuclear power. As in, not a single one of those requirements is fulfilled by any commercial design.