Life cycle analysis of incandescent, CFL, and LED light bulbs – It’s important to make sure when you’re using a new technology that supposedly saves energy, that you haven’t just shifted the energy consumption from the operational to the manufacturing portion of the product’s life cycle. This study compares three different lighting technologies: incandescent, compact fluorescent, and LED bulbs, and asks what the total energy input is to get ~400 lumens of light for 25,000 hours. Both CFLs and LEDs save about 80% of the energy over incandescent bulbs. For all bulb types, the embodied energy of manufacturing is only about 2% of the total energy consumed over the bulb’s life. CFLs and LEDs were roughly equivalent energetically at the time of this study, but the LEDs produced less in the way of toxic byproducts. The general expectation is that the efficiency of LED lighting will continue to improve, while CFLs are a pretty mature technology. The two best LED bulbs on the market today, with warm yellow light, compatible with dimmer switches, and giving about 800 lumens of light output (equivalent to a 60W incandescent bulb), seem to be this 13W one from Lighting Science ($30) and the 12W Philips A19 EnduraLED ($40). The prices seem high, but as with gas furnaces and boilers, electric motors and pumps, the cost of the electricity or fuel you run through the device ends up dwarfing the capital cost over its lifetime, so paying top dollar for efficiency is worthwhile.