I use florecent plant lights 15 wats, here is the cool part
the power comes in and plugs in to an outdoor timer, a dusk till dawn sensor is plugged int the timer and the lights are pluged in to the sensor, the timer is set to come on at 6am and go off at 9pm so at 6am the lights come on as the timer is activated and the light sensor is activated because it is dark, when the sun comes out, the sensor is deactivated turning the lights off, when the sun goes down the sensor is again activated and the lights come on, at 9pm the timer is deactivated and the lights go off. completely automatic, maintenance free and energy efficient since the lights are only on when needed.