On the roof of every Israeli apartment building you find water heaters and solar panels-- the solar water heater is known (in one of the most fabulous Israeli appliance names) as a dude shemesh. In a country with this much sun, it only makes sense for us to heat our water using solar energy.
In the summer, this means that we have hot water all day long without paying a dime for heating. In the winter, you have to plan your showers carefully-- you can usually shower with hot water in the middle of the day, but in the evening you often need to heat the water using electricity (via a special switch in everyone's home-- if you flip a switch in your new Israeli apartment and nothing appears to happen, you may be heating your water). It takes about a half hour for the water in our dude shemesh to heat. Some people even use timers to insure hot water at specific times during the summer.
Don't forget to clean off your solar panels every so often! Dusty solar panels can't collect sunlight.
Are you a heat-at-specific-times or a flip-the-switch-and-wait kind of winter showerer?