more than likely any LCD TV will (Unless a great big one) will use less power than the 13" TV you have now.
Look at the back of your TV, it should show the power (Watts or VA) that it uses. Then look at the new TV sets you are interested in LCD or LED LCD. You can even look the numbers up on the net for TV's you may be interested in. Most "LED" TV's are actually LED LCD TV's and you will pay more for these compared to a "regular LCD TV" soo you wont live long nuff to see the money you save going the LED LCD route (yet).
Course stay away from plasma, they are gettin the power levels they draw down, but if you leave the TV on all the time , as you say, The LCD will last longer.
Good luck

Gary

Here's a chart that should answer your question.

Here is a link that might be useful: Power Used For LCD And Plasma HDTVs

dodge and jimi....I have a June 2002 13" Orion. On the back it says 120 v, 60mhz, 54 watt. I take this to mean that it uses 54 watts. There isn't a LCD tv on the site you gave me jimi that came close to that. I would want a 40" (about", and they seem to be almost 3 times the wattage if I am reading the chart correctly.

From what I know the LED TVs have used quite a bit more power than a traditional LCD TV in the same screen size. This type of LED television approaches plasma displays in power usage. The edge lit LED televisions use less power than an LCD of the same size.

Here is a link that might be useful: led televisions

I have to say the LED TV are way cooler if you can afford one. Go for it.

Here is a link that might be useful: Life Insurance Comparison