SSDs don't save much power. HDDs consume about 4-15% of the laptop power (mostly at the low end if you're not constantly thrashing the drive), and the SSD power consumption is about half that.

Here is data on HDD power use: http://www.crhc.uiuc.edu/~mahesri/cl...t_cs497yyz.pdf

Samsung web site says SSDs give at best a 50% savings.

Bottom line: HDD to SSD should cut consumption by only a few percent.