Replacing LED light bulbs before they fail may be greener

Households can reduce their energy bills and cut their contribution to greenhouse gas emissions by switching to more efficient lighting, but what's the best strategy to maximize savings in cost, energy and emissions? Should we buy our new bulbs today or wait for further improvements to the technology?

Having considered the options in detail, researchers based at the University of Michigan, US, have drawn up a list of household lighting guidelines to help us make the right decision.

All incandescent and halogen light bulbs should be replaced immediately with compact fluorescent lamps or LED versions, they found, assuming an average use of 3 hours per day. But if you are already using compact fluorescent lamps then the next step depends on several factors.