Baseboard Heat?

[Brie Schmidt]

We have a unit that currently has baseboard heat (electric) The tenants we had in there years ago never complained about the cost of heat, but the tenants we have had for the past 2 years say that their bill goes up $400-$500 a month during winter.  

The baseboards were in place when we bought it and that unit was redone within the last 10 years.  Has technology advanced enough that if we replace the baseboards they will be more energy efficient and lower their monthly heating costs?