Choosing an LED lightbulb

It is getting ever trickier to find incandescent bulbs. Almost all rich countries are phasing them out because they squander so much energy as heat rather than visible light. But they have ardent fans. Unlike many of their would-be successors, such as compact fluorescent lights (CFLs) and light-emitting diodes (LEDs), they cast a full spectrum of colours reminiscent of daylight, need no time to warm up and can be dimmed. Ahead of the European phase-out in 2009, for example, Vaclav Klaus, the Czech president, urged people to hoard a lifetime’s worth.