regardless what kind of power plant is needed (either nuclear or anything else), I agree with salvia, that energy efficiency is important, but will not be enough to supply our needs.
understanding from few articles that I read, that our energy demand will doubled in 2020, while as the energy efficiency that was proposed by some manufactured by today is only able to save energy by 20-30% max.
so yes, efficiency is greatly needed, but the answer of providing a safe and sufficient powerplant is also need to be implemented.