Purchasing a television is important when looking at the energy consumption that your conventional tv set could potentially use. Depending on the type of television you choose, it could use between 45 watts or as much as 500 watts of electricity. This could mean between $13 to $145 per year to run. The most efficient televisions to date are smaller LCD tv's, and the most power hungry ones are large plasma sets. Rear Projection televisions can generally be energy efficient, however they are very large and don't get nearly as bright.

Here is a good source if you're looking for the differences between the energy efficiency when purchasing a new set.