A paper calendar placed in the kitchen is always available and can be glanced at from across the room. In a field study of the LINC digital calendar prototype, we achieved the same level of availability at the cost of leaving a computer running all the time. This brought to my attention the tension between the benefit of providing an ambient display that is always available and the cost in terms of power consumption. As we design and build future ambient displays for the home, we need to carefully consider this tension between availability and energy use.