Have you thought about LED lighting? LED Light bulbs are semiconductors, just like a computer chip. When electricity is passed through them, they emit energy in the form of light. They are injected with certain chemicals, that determine their light color. LEDs convert the majority of energy passed through them to light, as opposed to incandescent bulbs that produce light as a by-product of being heated thus they can be up to 90% more efficient than traditional household filament bulbs - and these will still fit in all your old fixtures.