@kenw as mentioned by @keyser even if you could shave off a few watts - is it worth the risk that might come with instability? Your not talking from going from 100w to 10w, lets say you could save 2 watts.
In the big picture at say 15 cents per kwh.. Do the math.. Your talking like $2.63 over the year..
And you might be below that or even if you were paying 50 cents a kwh your only talking $8.77 over the year..
This cost savings are in no way worth any effort even, or the risk of problems.
Now if you were talking say changing some hardware or whatever and went from 150W to 10 watts.. So a savings of like 180 dollars a year.. Hey such a savings might be worth even changing hardware - because you might recoup the cost of the new hardware in a few years.