中国称为节能灯，**称为省电灯泡，或称电子灯泡、紧凑型萤光灯及一体式萤光灯，港澳地区粤语称悭电胆，是指将萤光灯与镇流器组合成一个整体的照明设备。悭电胆的尺寸与白炽灯相近，与灯座的接口也和白炽灯相同，所以可以直接替换白炽灯。节能灯的消耗功率与萤光灯相近，与萤光灯相比之下没有比较省电而且单价高出甚多。选购前应留意单价、使用场所、使用时间及频率，勿被「省电」的行销噱头误导。

A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light, and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent lamp; some types fit into light fixtures formerly used for incandescent lamps. The lamps use a tube which is curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp.