Cut the Power
For energy-saving smarts, add smart power strips to your green bathroom. These actually monitor what's going on with each appliance plugged into them. If the power usage drops to stand-by mode, that single outlet shuts off. That way, it cuts off the "vampire" that sucks power even when things aren't in use.
There are a couple of things you can do to reduce the amount of electric lighting you use. The simplest thing is to replace your standard light bulbs with motion-activated lights. These screw right into your regular light socket. They'll automatically turn on when you walk into the room and automatically turn off when you walk out.
Daylighting requires a little more work. Basically, daylighting brings the sunshine into your room through the roof, even in places where you wouldn't be able to install a skylight. It uses reflective tubing, an exterior sunlight collector, and an interior diffusing lens in the ceiling to channel sunlight into a room. The tubing can be angled through the roof and attic spaces to reach the room you want to brighten with natural light. It's a relatively simple installation that doesn't need major construction or framing.