I went to Menards yesterday and picked up two boxes of LED bulbs that replace the four foot fluorescent bulbs. These are the style that you do away with the fluorescent ballast and wire one end hot while the other end is just a holder. These were $20 for a two pack so $40 for the fixture. The swap wasn't bad and the light output is nice. I'll wait until they have the 11% sale and go get enough to do every fixture. I don't think the picture does the bulbs justice but the fixture farthest away on the left is the one I replaced. In the shop it's a noticeable difference.
