Energy efficiency may not be something you care a lot about. If you're in a public school, someone else pays for the electricity. However, many schools are seriously under powered. If your school is having problems with equipment frequently tripping circuit breakers or crashing when the air conditioners go on, then you may want to keep an eye open for energy-efficient servers. Sun already has a design that uses much less power. Other vendors will follow. While they will be advertising on cost savings, you can start to think about new locations that equipment might now be able to function.
Congress begins push for energy-efficient servers: "The House of Representatives has approved a bill calling on the EPA to study the use of energy-efficient servers that can cut the power demand of equipment-packed data centers."