If you use the lights a lot, the electrical savings can be startling.
Last year I replaced every lamp in our "Land Yacht" (including fluorescent tubes) with LED lights. These are all 12-volt DC lighting fixtures.
The drop in power consumption was amazing! The coach has a digital current monitor that shows me how many amps are being drawn from the 12 volt house batteries at any given moment. After the conversion, I could turn on every light in the coach, and the power consumption was less than the power drawn by just the four fluorescent fixtures in the living room prior to the conversion.
